fmt

Log not implemented messages as debug in prometheus metrics. (#477 )
Support for prepared statements (#474 )
2026-03-23 01:16:30 +00:00 · 2023-06-17 08:57:19 -07:00 · 2023-06-16 18:48:38 -07:00 · 2023-06-16 12:57:44 -07:00 · 2023-06-12 09:23:56 -07:00 · 2023-06-12 00:51:24 -07:00
44 changed files with 5223 additions and 1056 deletions
--- a/CONFIG.md
+++ b/CONFIG.md
@@ -49,6 +49,14 @@ default: 30000 # milliseconds

 How long an idle connection with a server is left open (ms).

+### server_lifetime
+```
+path: general.server_lifetime
+default: 86400000 # 24 hours
+```
+
+Max connection lifetime before it's closed, even if actively used.
+
 ### idle_client_in_transaction_timeout
 ```
 path: general.idle_client_in_transaction_timeout
@@ -180,6 +188,22 @@ default: "admin_pass"

 Password to access the virtual administrative database

+### dns_cache_enabled
+```
+path: general.dns_cache_enabled
+default: false
+```
+When enabled, ip resolutions for server connections specified using hostnames will be cached
+and checked for changes every `dns_max_ttl` seconds. If a change in the host resolution is found
+old ip connections are closed (gracefully) and new connections will start using new ip.
+
+### dns_max_ttl
+```
+path: general.dns_max_ttl
+default: 30
+```
+Specifies how often (in seconds) cached ip addresses for servers are rechecked (see `dns_cache_enabled`).
+
 ## `pools.<pool_name>` Section

 ### pool_mode
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,6 +26,27 @@ version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bddcadddf5e9015d310179a59bb28c4d4b9920ad0f11e8e14dbadf654890c9a6"

+[[package]]
+name = "async-stream"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dad5c83079eae9969be7fadefe640a1c566901f05ff91ab221de4b6f68d9507e"
+dependencies = [
+ "async-stream-impl",
+ "futures-core",
+]
+
+[[package]]
+name = "async-stream-impl"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10f203db73a71dfa2fb6dd22763990fa26f3d2625a6da2da900d23b87d26be27"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "async-trait"
 version = "0.1.68"
@@ -62,9 +83,9 @@ checksum = "a4a4ddaa51a5bc52a6948f74c06d20aaaddb71924eab79b8c97a8c556e942d6a"

 [[package]]
 name = "bb8"
-version = "0.8.0"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1627eccf3aa91405435ba240be23513eeca466b5dc33866422672264de061582"
+checksum = "98b4b0f25f18bcdc3ac72bdb486ed0acf7e185221fd4dc985bc15db5800b0ba2"
 dependencies = [
 "async-trait",
 "futures-channel",
@@ -212,6 +233,12 @@ dependencies = [
 "syn 1.0.109",
 ]

+[[package]]
+name = "data-encoding"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ee2393c4a91429dffb4bedf19f4d6abf27d8a732c8ce4980305d782e5426d57"
+
 [[package]]
 name = "digest"
 version = "0.10.6"
@@ -223,6 +250,24 @@ dependencies = [
 "subtle",
 ]

+[[package]]
+name = "either"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
+
+[[package]]
+name = "enum-as-inner"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9720bba047d567ffc8a3cba48bf19126600e249ab7f128e9233e6376976a116"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "env_logger"
 version = "0.10.0"
@@ -275,6 +320,15 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"

+[[package]]
+name = "form_urlencoded"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9c384f161156f5260c24a097c56119f9be8c798586aecc13afbcbe7b7e26bf8"
+dependencies = [
+ "percent-encoding",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.28"
@@ -410,6 +464,12 @@ version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"

+[[package]]
+name = "heck"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9"
+
 [[package]]
 name = "hermit-abi"
 version = "0.2.6"
@@ -434,6 +494,17 @@ dependencies = [
 "digest",
 ]

+[[package]]
+name = "hostname"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c731c3e10504cc8ed35cfe2f1db4c9274c3d35fa486e3b31df46f068ef3e867"
+dependencies = [
+ "libc",
+ "match_cfg",
+ "winapi",
+]
+
 [[package]]
 name = "http"
 version = "0.2.9"
@@ -522,6 +593,27 @@ dependencies = [
 "cxx-build",
 ]

+[[package]]
+name = "idna"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "418a0a6fab821475f634efe3ccc45c013f742efe03d853e8d3355d5cb850ecf8"
+dependencies = [
+ "matches",
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
+[[package]]
+name = "idna"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e14ddfc70884202db2244c223200c204c2bda1bc6e0998d11b5e024d657209e6"
+dependencies = [
+ "unicode-bidi",
+ "unicode-normalization",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.2"
@@ -542,6 +634,24 @@ dependencies = [
 "windows-sys",
 ]

+[[package]]
+name = "ipconfig"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd302af1b90f2463a98fa5ad469fc212c8e3175a41c3068601bfa2727591c5be"
+dependencies = [
+ "socket2",
+ "widestring",
+ "winapi",
+ "winreg",
+]
+
+[[package]]
+name = "ipnet"
+version = "2.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f88c5561171189e69df9d98bcf18fd5f9558300f7ea7b801eb8a0fd748bd8745"
+
 [[package]]
 name = "is-terminal"
 version = "0.4.4"
@@ -554,6 +664,15 @@ dependencies = [
 "windows-sys",
 ]

+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.5"
@@ -589,6 +708,12 @@ dependencies = [
 "wasm-bindgen",
 ]

+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.139"
@@ -604,6 +729,12 @@ dependencies = [
 "cc",
 ]

+[[package]]
+name = "linked-hash-map"
+version = "0.5.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.1.4"
@@ -622,13 +753,31 @@ dependencies = [

 [[package]]
 name = "log"
-version = "0.4.17"
+version = "0.4.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
+checksum = "b06a4cde4c0f271a446782e3eff8de789548ce57dbc8eca9292c27f4a42004b4"
+
+[[package]]
+name = "lru-cache"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31e24f1ad8321ca0e8a1e0ac13f23cb668e6f5466c2c57319f6a5cf1cc8e3b1c"
 dependencies = [
- "cfg-if",
+ "linked-hash-map",
 ]

+[[package]]
+name = "match_cfg"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffbee8634e0d45d258acb448e7eaab3fce7a0a467395d4d9f228e3c1f01fb2e4"
+
+[[package]]
+name = "matches"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
+
 [[package]]
 name = "md-5"
 version = "0.10.5"
@@ -737,9 +886,15 @@ dependencies = [
 "windows-sys",
 ]

+[[package]]
+name = "percent-encoding"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "478c572c3d73181ff3c2539045f6eb99e5491218eae919370993b890cdbdd98e"
+
 [[package]]
 name = "pgcat"
-version = "1.0.1"
+version = "1.0.2-alpha3"
 dependencies = [
 "arc-swap",
 "async-trait",
@@ -754,6 +909,7 @@ dependencies = [
 "futures",
 "hmac",
 "hyper",
+ "itertools",
 "jemallocator",
 "log",
 "md-5",
@@ -762,12 +918,15 @@ dependencies = [
 "once_cell",
 "parking_lot",
 "phf",
+ "pin-project",
 "postgres-protocol",
 "rand",
 "regex",
+ "rustls",
 "rustls-pemfile",
 "serde",
 "serde_derive",
+ "serde_json",
 "sha-1",
 "sha2",
 "socket2",
@@ -775,7 +934,10 @@ dependencies = [
 "stringprep",
 "tokio",
 "tokio-rustls",
+ "tokio-test",
 "toml",
+ "trust-dns-resolver",
+ "webpki-roots",
 ]

 [[package]]
@@ -820,6 +982,26 @@ dependencies = [
 "siphasher",
 ]

+[[package]]
+name = "pin-project"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c95a7476719eab1e366eaf73d0260af3021184f18177925b07f54b30089ceead"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39407670928234ebc5e6e580247dd567ad73a3578460c5990f9503df207e8f07"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.9",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.9"
@@ -865,6 +1047,12 @@ dependencies = [
 "unicode-ident",
 ]

+[[package]]
+name = "quick-error"
+version = "1.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
+
 [[package]]
 name = "quote"
 version = "1.0.26"
@@ -915,9 +1103,9 @@ dependencies = [

 [[package]]
 name = "regex"
-version = "1.8.0"
+version = "1.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac6cf59af1067a3fb53fbe5c88c053764e930f932be1d71d3ffe032cbe147f59"
+checksum = "d0ab3ca65655bb1e41f2a8c8cd662eb4fb035e67c3f78da1d61dffe89d07300f"
 dependencies = [
 "aho-corasick",
 "memchr",
@@ -926,9 +1114,19 @@ dependencies = [

 [[package]]
 name = "regex-syntax"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "436b050e76ed2903236f032a59761c1eb99e1b0aead2c257922771dab1fc8c78"
+
+[[package]]
+name = "resolv-conf"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6868896879ba532248f33598de5181522d8b3d9d724dfd230911e1a7d4822f5"
+checksum = "52e44394d2086d010551b14b53b1f24e31647570cd1deb0379e2c21b329aba00"
+dependencies = [
+ "hostname",
+ "quick-error",
+]

 [[package]]
 name = "ring"
@@ -961,9 +1159,9 @@ dependencies = [

 [[package]]
 name = "rustls"
-version = "0.21.0"
+version = "0.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07180898a28ed6a7f7ba2311594308f595e3dd2e3c3812fa0a80a47b45f17e5d"
+checksum = "c911ba11bc8433e811ce56fde130ccf32f5127cab0e0194e9c68c5a5b671791e"
 dependencies = [
 "log",
 "ring",
@@ -990,6 +1188,12 @@ dependencies = [
 "untrusted",
 ]

+[[package]]
+name = "ryu"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f91339c0467de62360649f8d3e185ca8de4224ff281f66000de5eb2a77a79041"
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
@@ -1017,6 +1221,9 @@ name = "serde"
 version = "1.0.160"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bb2f3770c8bce3bcda7e149193a069a0f4365bda1fa5cd88e03bca26afc1216c"
+dependencies = [
+ "serde_derive",
+]

 [[package]]
 name = "serde_derive"
@@ -1030,10 +1237,21 @@ dependencies = [
 ]

 [[package]]
-name = "serde_spanned"
-version = "0.6.1"
+name = "serde_json"
+version = "1.0.96"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0efd8caf556a6cebd3b285caf480045fcc1ac04f6bd786b09a6f11af30c4fcf4"
+checksum = "057d394a50403bcac12672b2b18fb387ab6d289d957dab67dd201875391e52f1"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "serde_spanned"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93107647184f6027e3b7dcb2e11034cf95ffa1e3a682c67951963ac69c1c007d"
 dependencies = [
 "serde",
 ]
@@ -1108,11 +1326,23 @@ checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"

 [[package]]
 name = "sqlparser"
-version = "0.33.0"
+version = "0.34.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "355dc4d4b6207ca8a3434fc587db0a8016130a574dbcdbfb93d7f7b5bc5b211a"
+checksum = "37d3706eefb17039056234df6b566b0014f303f867f2656108334a55b8096f59"
 dependencies = [
 "log",
+ "sqlparser_derive",
+]
+
+[[package]]
+name = "sqlparser_derive"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55fe75cb4a364c7f7ae06c7dbbc8d84bddd85d6cdf9975963c3935bc1991761e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
 ]

 [[package]]
@@ -1168,6 +1398,26 @@ dependencies = [
 "winapi-util",
 ]

+[[package]]
+name = "thiserror"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10deb33631e3c9018b9baf9dcbbc4f737320d2b576bac10f6aefa048fa407e3e"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "982d17546b47146b28f7c22e3d08465f6b8903d0ea13c1660d9d84a6e7adcdbb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "time"
 version = "0.1.45"
@@ -1235,6 +1485,30 @@ dependencies = [
 "tokio",
 ]

+[[package]]
+name = "tokio-stream"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d660770404473ccd7bc9f8b28494a811bc18542b915c0855c51e8f419d5223ce"
+dependencies = [
+ "futures-core",
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-test"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53474327ae5e166530d17f2d956afcb4f8a004de581b3cae10f12006bc8163e3"
+dependencies = [
+ "async-stream",
+ "bytes",
+ "futures-core",
+ "tokio",
+ "tokio-stream",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.7.7"
@@ -1251,9 +1525,9 @@ dependencies = [

 [[package]]
 name = "toml"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b403acf6f2bb0859c93c7f0d967cb4a75a7ac552100f9322faf64dc047669b21"
+checksum = "d6135d499e69981f9ff0ef2167955a5333c35e36f6937d382974566b3d5b94ec"
 dependencies = [
 "serde",
 "serde_spanned",
@@ -1263,18 +1537,18 @@ dependencies = [

 [[package]]
 name = "toml_datetime"
-version = "0.6.1"
+version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ab8ed2edee10b50132aed5f331333428b011c99402b5a534154ed15746f9622"
+checksum = "5a76a9312f5ba4c2dec6b9161fdf25d87ad8a09256ccea5a556fef03c706a10f"
 dependencies = [
 "serde",
 ]

 [[package]]
 name = "toml_edit"
-version = "0.19.6"
+version = "0.19.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08de71aa0d6e348f070457f85af8bd566e2bc452156a423ddf22861b3a953fae"
+checksum = "92d964908cec0d030b812013af25a0e57fddfadb1e066ecc6681d86253129d4f"
 dependencies = [
 "indexmap",
 "serde",
@@ -1297,9 +1571,21 @@ checksum = "8ce8c33a8d48bd45d624a6e523445fd21ec13d3653cd51f681abf67418f54eb8"
 dependencies = [
 "cfg-if",
 "pin-project-lite",
+ "tracing-attributes",
 "tracing-core",
 ]

+[[package]]
+name = "tracing-attributes"
+version = "0.1.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4017f8f45139870ca7e672686113917c71c7a6e02d4924eda67186083c03081a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "tracing-core"
 version = "0.1.30"
@@ -1309,6 +1595,51 @@ dependencies = [
 "once_cell",
 ]

+[[package]]
+name = "trust-dns-proto"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4f7f83d1e4a0e4358ac54c5c3681e5d7da5efc5a7a632c90bb6d6669ddd9bc26"
+dependencies = [
+ "async-trait",
+ "cfg-if",
+ "data-encoding",
+ "enum-as-inner",
+ "futures-channel",
+ "futures-io",
+ "futures-util",
+ "idna 0.2.3",
+ "ipnet",
+ "lazy_static",
+ "rand",
+ "smallvec",
+ "thiserror",
+ "tinyvec",
+ "tokio",
+ "tracing",
+ "url",
+]
+
+[[package]]
+name = "trust-dns-resolver"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aff21aa4dcefb0a1afbfac26deb0adc93888c7d295fb63ab273ef276ba2b7cfe"
+dependencies = [
+ "cfg-if",
+ "futures-util",
+ "ipconfig",
+ "lazy_static",
+ "lru-cache",
+ "parking_lot",
+ "resolv-conf",
+ "smallvec",
+ "thiserror",
+ "tokio",
+ "tracing",
+ "trust-dns-proto",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.4"
@@ -1354,6 +1685,17 @@ version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"

+[[package]]
+name = "url"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d68c799ae75762b8c3fe375feb6600ef5602c883c5d21eb51c09f22b83c4643"
+dependencies = [
+ "form_urlencoded",
+ "idna 0.3.0",
+ "percent-encoding",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.4"
@@ -1446,6 +1788,21 @@ dependencies = [
 "wasm-bindgen",
 ]

+[[package]]
+name = "webpki-roots"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa54963694b65584e170cf5dc46aeb4dcaa5584e652ff5f3952e56d66aff0125"
+dependencies = [
+ "rustls-webpki",
+]
+
+[[package]]
+name = "widestring"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17882f045410753661207383517a6f62ec3dbeb6a4ed2acce01f0728238d1983"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -1545,9 +1902,18 @@ checksum = "447660ad36a13288b1db4d4248e857b510e8c3a225c822ba4fb748c0aafecffd"

 [[package]]
 name = "winnow"
-version = "0.3.3"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "faf09497b8f8b5ac5d3bb4d05c0a99be20f26fd3d5f2db7b0716e946d5103658"
+checksum = "61de7bac303dc551fe038e2b3cef0f571087a47571ea6e79a87692ac99b99699"
 dependencies = [
 "memchr",
 ]
+
+[[package]]
+name = "winreg"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "80d0f4e272c85def139476380b12f9ac60926689dd2e01d4923222f40580869d"
+dependencies = [
+ "winapi",
+]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pgcat"
-version = "1.0.1"
+version = "1.0.2-alpha3"
 edition = "2021"

 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
@@ -8,18 +8,18 @@ edition = "2021"
 tokio = { version = "1", features = ["full"] }
 bytes = "1"
 md-5 = "0.10"
-bb8 = "0.8.0"
+bb8 = "0.8.1"
 async-trait = "0.1"
 rand = "0.8"
 chrono = "0.4"
 sha-1 = "0.10"
 toml = "0.7"
-serde = "1"
+serde = { version = "1", features = ["derive"] }
 serde_derive = "1"
 regex = "1"
 num_cpus = "1"
 once_cell = "1"
-sqlparser = "0.33.0"
+sqlparser = {version = "0.34", features = ["visitor"] }
 log = "0.4"
 arc-swap = "1"
 env_logger = "0.10"
@@ -39,6 +39,14 @@ nix = "0.26.2"
 atomic_enum = "0.2.0"
 postgres-protocol = "0.6.5"
 fallible-iterator = "0.2"
+pin-project = "1"
+webpki-roots = "0.23"
+rustls = { version = "0.21", features = ["dangerous_configuration"] }
+trust-dns-resolver = "0.22.0"
+tokio-test = "0.4.2"
+serde_json = "1"
+itertools = "0.10"

 [target.'cfg(not(target_env = "msvc"))'.dependencies]
 jemallocator = "0.5.0"
+
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ PostgreSQL pooler and proxy (like PgBouncer) with support for sharding, load bal
 | Failover | **Stable** | Queries are automatically rerouted around broken replicas, validated by regular health checks. |
 | Admin database statistics | **Stable** | Pooler statistics and administration via the `pgbouncer` and `pgcat` databases. |
 | Prometheus statistics | **Stable** | Statistics are reported via a HTTP endpoint for Prometheus. |
-| Client TLS | **Stable** | Clients can connect to the pooler using TLS/SSL. |
+| SSL/TLS | **Stable** | Clients can connect to the pooler using TLS. Pooler can connect to Postgres servers using TLS. |
 | Client/Server authentication | **Stable** | Clients can connect using MD5 authentication, supported by `libpq` and all Postgres client drivers. PgCat can connect to Postgres using MD5 and SCRAM-SHA-256. |
 | Live configuration reloading | **Stable** | Identical to PgBouncer; all settings can be reloaded dynamically (except `host` and `port`). |
 | Auth passthrough | **Stable** | MD5 password authentication can be configured to use an `auth_query` so no cleartext passwords are needed in the config file.|
--- a/dev/Dockerfile
+++ b/dev/Dockerfile
@@ -1,4 +1,4 @@
-FROM rust:bullseye
+FROM rust:1.70-bullseye

 # Dependencies
 RUN apt-get update -y \
--- a/dev/docker-compose.yaml
+++ b/dev/docker-compose.yaml
@@ -25,7 +25,7 @@ x-common-env-pg:

 services:
  main:
-    image: kubernetes/pause
+    image: gcr.io/google_containers/pause:3.2
    ports:
      - 6432

@@ -64,7 +64,7 @@ services:
      <<: *common-env-pg
      POSTGRES_INITDB_ARGS: --auth-local=md5 --auth-host=md5 --auth=md5
      PGPORT: 10432
-    command: ["postgres", "-p", "5432", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-c", "pg_stat_statements.max=100000"]
+    command: ["postgres", "-p", "10432", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-c", "pg_stat_statements.max=100000"]

  toxiproxy:
    build: .
--- a/pgcat.minimal.toml
+++ b/pgcat.minimal.toml
@@ -0,0 +1,22 @@
+# This is an example of the most basic config
+# that will mimic what PgBouncer does in transaction mode with one server.
+
+[general]
+
+host = "0.0.0.0"
+port = 6433
+admin_username = "pgcat"
+admin_password = "pgcat"
+
+[pools.pgml.users.0]
+username = "postgres"
+password = "postgres"
+pool_size = 10
+min_pool_size = 1
+pool_mode = "transaction"
+
+[pools.pgml.shards.0]
+servers = [
+  ["127.0.0.1", 28815, "primary"]
+]
+database = "postgres"
--- a/pgcat.toml
+++ b/pgcat.toml
@@ -23,6 +23,9 @@ connect_timeout = 5000 # milliseconds
 # How long an idle connection with a server is left open (ms).
 idle_timeout = 30000 # milliseconds

+# Max connection lifetime before it's closed, even if actively used.
+server_lifetime = 86400000 # 24 hours
+
 # How long a client is allowed to be idle while in a transaction (ms).
 idle_client_in_transaction_timeout = 0 # milliseconds

@@ -57,10 +60,19 @@ tcp_keepalives_count = 5
 # Number of seconds between keepalive packets.
 tcp_keepalives_interval = 5

+# Handle prepared statements.
+prepared_statements = true
+
 # Path to TLS Certificate file to use for TLS connections
-# tls_certificate = "server.cert"
+# tls_certificate = ".circleci/server.cert"
 # Path to TLS private key file to use for TLS connections
-# tls_private_key = "server.key"
+# tls_private_key = ".circleci/server.key"
+
+# Enable/disable server TLS
+server_tls = false
+
+# Verify server certificate is completely authentic.
+verify_server_certificate = false

 # User name to access the virtual administrative database (pgbouncer or pgcat)
 # Connecting to that database allows running commands like `SHOW POOLS`, `SHOW DATABASES`, etc..
@@ -68,6 +80,58 @@ admin_username = "admin_user"
 # Password to access the virtual administrative database
 admin_password = "admin_pass"

+# Default plugins that are configured on all pools.
+[plugins]
+
+# Prewarmer plugin that runs queries on server startup, before giving the connection
+# to the client.
+[plugins.prewarmer]
+enabled = false
+queries = [
+  "SELECT pg_prewarm('pgbench_accounts')",
+]
+
+# Log all queries to stdout.
+[plugins.query_logger]
+enabled = false
+
+# Block access to tables that Postgres does not allow us to control.
+[plugins.table_access]
+enabled = false
+tables = [
+  "pg_user",
+  "pg_roles",
+  "pg_database",
+]
+
+# Intercept user queries and give a fake reply.
+[plugins.intercept]
+enabled = true
+
+[plugins.intercept.queries.0]
+
+query = "select current_database() as a, current_schemas(false) as b"
+schema = [
+  ["a", "text"],
+  ["b", "text"],
+]
+result = [
+  ["${DATABASE}", "{public}"],
+]
+
+[plugins.intercept.queries.1]
+
+query = "select current_database(), current_schema(), current_user"
+schema = [
+  ["current_database", "text"],
+  ["current_schema", "text"],
+  ["current_user", "text"],
+]
+result = [
+  ["${DATABASE}", "public", "${USER}"],
+]
+
+
 # pool configs are structured as pool.<pool_name>
 # the pool_name is what clients use as database name when connecting.
 # For a pool named `sharded_db`, clients access that pool using connection string like
@@ -137,6 +201,61 @@ idle_timeout = 40000
 # Connect timeout can be overwritten in the pool
 connect_timeout = 3000

+# When enabled, ip resolutions for server connections specified using hostnames will be cached
+# and checked for changes every `dns_max_ttl` seconds. If a change in the host resolution is found
+# old ip connections are closed (gracefully) and new connections will start using new ip.
+# dns_cache_enabled = false
+
+# Specifies how often (in seconds) cached ip addresses for servers are rechecked (see `dns_cache_enabled`).
+# dns_max_ttl = 30
+
+# Plugins can be configured on a pool-per-pool basis. This overrides the global plugins setting,
+# so all plugins have to be configured here again.
+[pool.sharded_db.plugins]
+
+[pools.sharded_db.plugins.prewarmer]
+enabled = true
+queries = [
+  "SELECT pg_prewarm('pgbench_accounts')",
+]
+
+[pools.sharded_db.plugins.query_logger]
+enabled = false
+
+[pools.sharded_db.plugins.table_access]
+enabled = false
+tables = [
+  "pg_user",
+  "pg_roles",
+  "pg_database",
+]
+
+[pools.sharded_db.plugins.intercept]
+enabled = true
+
+[pools.sharded_db.plugins.intercept.queries.0]
+
+query = "select current_database() as a, current_schemas(false) as b"
+schema = [
+  ["a", "text"],
+  ["b", "text"],
+]
+result = [
+  ["${DATABASE}", "{public}"],
+]
+
+[pools.sharded_db.plugins.intercept.queries.1]
+
+query = "select current_database(), current_schema(), current_user"
+schema = [
+  ["current_database", "text"],
+  ["current_schema", "text"],
+  ["current_user", "text"],
+]
+result = [
+  ["${DATABASE}", "public", "${USER}"],
+]
+
 # User configs are structured as pool.<pool_name>.users.<user_index>
 # This section holds the credentials for users that may connect to this cluster
 [pools.sharded_db.users.0]
@@ -206,6 +325,8 @@ sharding_function = "pg_bigint_hash"
 username = "simple_user"
 password = "simple_user"
 pool_size = 5
+min_pool_size = 3
+server_lifetime = 60000
 statement_timeout = 0

 [pools.simple_db.shards.0]
--- a/src/admin.rs
+++ b/src/admin.rs
@@ -1,4 +1,5 @@
 use crate::pool::BanReason;
+use crate::stats::pool::PoolStats;
 use bytes::{Buf, BufMut, BytesMut};
 use log::{error, info, trace};
 use nix::sys::signal::{self, Signal};
@@ -12,9 +13,9 @@ use tokio::time::Instant;
 use crate::config::{get_config, reload_config, VERSION};
 use crate::errors::Error;
 use crate::messages::*;
+use crate::pool::ClientServerMap;
 use crate::pool::{get_all_pools, get_pool};
-use crate::stats::{get_client_stats, get_pool_stats, get_server_stats, ClientState, ServerState};
-use crate::ClientServerMap;
+use crate::stats::{get_client_stats, get_server_stats, ClientState, ServerState};

 pub fn generate_server_info_for_admin() -> BytesMut {
    let mut server_info = BytesMut::new();
@@ -254,39 +255,12 @@ async fn show_pools<T>(stream: &mut T) -> Result<(), Error>
 where
    T: tokio::io::AsyncWrite + std::marker::Unpin,
 {
-    let all_pool_stats = get_pool_stats();
-
-    let columns = vec![
-        ("database", DataType::Text),
-        ("user", DataType::Text),
-        ("pool_mode", DataType::Text),
-        ("cl_idle", DataType::Numeric),
-        ("cl_active", DataType::Numeric),
-        ("cl_waiting", DataType::Numeric),
-        ("cl_cancel_req", DataType::Numeric),
-        ("sv_active", DataType::Numeric),
-        ("sv_idle", DataType::Numeric),
-        ("sv_used", DataType::Numeric),
-        ("sv_tested", DataType::Numeric),
-        ("sv_login", DataType::Numeric),
-        ("maxwait", DataType::Numeric),
-        ("maxwait_us", DataType::Numeric),
-    ];
-
+    let pool_lookup = PoolStats::construct_pool_lookup();
    let mut res = BytesMut::new();
-    res.put(row_description(&columns));
-
-    for ((_user_pool, _pool), pool_stats) in all_pool_stats {
-        let mut row = vec![
-            pool_stats.database(),
-            pool_stats.user(),
-            pool_stats.pool_mode().to_string(),
-        ];
-        pool_stats.populate_row(&mut row);
-        pool_stats.clear_maxwait();
-        res.put(data_row(&row));
-    }
-
+    res.put(row_description(&PoolStats::generate_header()));
+    pool_lookup.iter().for_each(|(_identifier, pool_stats)| {
+        res.put(data_row(&pool_stats.generate_row()));
+    });
    res.put(command_complete("SHOW"));

    // ReadyForQuery
@@ -334,17 +308,17 @@ where
                let paused = pool.paused();

                res.put(data_row(&vec![
-                    address.name(),                         // name
-                    address.host.to_string(),               // host
-                    address.port.to_string(),               // port
-                    database_name.to_string(),              // database
-                    pool_config.user.username.to_string(),  // force_user
-                    pool_config.user.pool_size.to_string(), // pool_size
-                    "0".to_string(),                        // min_pool_size
-                    "0".to_string(),                        // reserve_pool
-                    pool_config.pool_mode.to_string(),      // pool_mode
-                    pool_config.user.pool_size.to_string(), // max_connections
-                    pool_state.connections.to_string(),     // current_connections
+                    address.name(),                                          // name
+                    address.host.to_string(),                                // host
+                    address.port.to_string(),                                // port
+                    database_name.to_string(),                               // database
+                    pool_config.user.username.to_string(),                   // force_user
+                    pool_config.user.pool_size.to_string(),                  // pool_size
+                    pool_config.user.min_pool_size.unwrap_or(0).to_string(), // min_pool_size
+                    "0".to_string(),                                         // reserve_pool
+                    pool_config.pool_mode.to_string(),                       // pool_mode
+                    pool_config.user.pool_size.to_string(),                  // max_connections
+                    pool_state.connections.to_string(),                      // current_connections
                    match paused {
                        // paused
                        true => "1".to_string(),
@@ -725,6 +699,8 @@ where
        ("bytes_sent", DataType::Numeric),
        ("bytes_received", DataType::Numeric),
        ("age_seconds", DataType::Numeric),
+        ("prepare_cache_hit", DataType::Numeric),
+        ("prepare_cache_miss", DataType::Numeric),
    ];

    let new_map = get_server_stats();
@@ -748,6 +724,14 @@ where
                .duration_since(server.connect_time())
                .as_secs()
                .to_string(),
+            server
+                .prepared_hit_count
+                .load(Ordering::Relaxed)
+                .to_string(),
+            server
+                .prepared_miss_count
+                .load(Ordering::Relaxed)
+                .to_string(),
        ];

        res.put(data_row(&row));
--- a/src/auth_passthrough.rs
+++ b/src/auth_passthrough.rs
@@ -77,6 +77,8 @@ impl AuthPassthrough {
            pool_size: 1,
            statement_timeout: 0,
            pool_mode: None,
+            server_lifetime: None,
+            min_pool_size: None,
        };

        let user = &address.username;
--- a/src/client.rs
+++ b/src/client.rs
@@ -3,8 +3,9 @@ use crate::pool::BanReason;
 /// Handle clients by pretending to be a PostgreSQL server.
 use bytes::{Buf, BufMut, BytesMut};
 use log::{debug, error, info, trace, warn};
+use once_cell::sync::Lazy;
 use std::collections::HashMap;
-use std::sync::Arc;
+use std::sync::{atomic::AtomicUsize, Arc};
 use std::time::Instant;
 use tokio::io::{split, AsyncReadExt, BufReader, ReadHalf, WriteHalf};
 use tokio::net::TcpStream;
@@ -13,17 +14,25 @@ use tokio::sync::mpsc::Sender;

 use crate::admin::{generate_server_info_for_admin, handle_admin};
 use crate::auth_passthrough::refetch_auth_hash;
-use crate::config::{get_config, get_idle_client_in_transaction_timeout, Address, PoolMode};
+use crate::config::{
+    get_config, get_idle_client_in_transaction_timeout, get_prepared_statements, Address, PoolMode,
+};
 use crate::constants::*;
 use crate::messages::*;
+use crate::plugins::PluginOutput;
 use crate::pool::{get_pool, ClientServerMap, ConnectionPool};
 use crate::query_router::{Command, QueryRouter};
 use crate::server::Server;
-use crate::stats::{ClientStats, PoolStats, ServerStats};
+use crate::stats::{ClientStats, ServerStats};
 use crate::tls::Tls;

 use tokio_rustls::server::TlsStream;

+/// Incrementally count prepared statements
+/// to avoid random conflicts in places where the random number generator is weak.
+pub static PREPARED_STATEMENT_COUNTER: Lazy<Arc<AtomicUsize>> =
+    Lazy::new(|| Arc::new(AtomicUsize::new(0)));
+
 /// Type of connection received from client.
 enum ClientConnectionType {
    Startup,
@@ -92,6 +101,9 @@ pub struct Client<S, T> {

    /// Used to notify clients about an impending shutdown
    shutdown: Receiver<()>,
+
+    /// Prepared statements
+    prepared_statements: HashMap<String, Parse>,
 }

 /// Client entrypoint.
@@ -539,6 +551,7 @@ where
                Some(md5_hash_password(username, password, &salt))
            } else {
                if !get_config().is_auth_query_configured() {
+                    wrong_password(&mut write, username).await?;
                    return Err(Error::ClientAuthImpossible(username.into()));
                }

@@ -565,6 +578,8 @@ where
                        }

                        Err(err) => {
+                            wrong_password(&mut write, username).await?;
+
                            return Err(Error::ClientAuthPassthroughError(
                                err.to_string(),
                                client_identifier,
@@ -587,7 +602,15 @@ where
                    client_identifier
                );

-                let fetched_hash = refetch_auth_hash(&pool).await?;
+                let fetched_hash = match refetch_auth_hash(&pool).await {
+                    Ok(fetched_hash) => fetched_hash,
+                    Err(err) => {
+                        wrong_password(&mut write, username).await?;
+
+                        return Err(err);
+                    }
+                };
+
                let new_password_hash = md5_hash_second_pass(&fetched_hash, &salt);

                // Ok password changed in server an auth is possible.
@@ -642,24 +665,12 @@ where
        ready_for_query(&mut write).await?;

        trace!("Startup OK");
-        let pool_stats = match get_pool(pool_name, username) {
-            Some(pool) => {
-                if !admin {
-                    pool.stats
-                } else {
-                    Arc::new(PoolStats::default())
-                }
-            }
-            None => Arc::new(PoolStats::default()),
-        };
-
        let stats = Arc::new(ClientStats::new(
            process_id,
            application_name,
            username,
            pool_name,
            tokio::time::Instant::now(),
-            pool_stats,
        ));

        Ok(Client {
@@ -682,6 +693,7 @@ where
            application_name: application_name.to_string(),
            shutdown,
            connected_to_server: false,
+            prepared_statements: HashMap::new(),
        })
    }

@@ -716,6 +728,7 @@ where
            application_name: String::from("undefined"),
            shutdown,
            connected_to_server: false,
+            prepared_statements: HashMap::new(),
        })
    }

@@ -754,6 +767,13 @@ where

        self.stats.register(self.stats.clone());

+        // Result returned by one of the plugins.
+        let mut plugin_output = None;
+
+        // Prepared statement being executed
+        let mut prepared_statement = None;
+        let mut will_prepare = false;
+
        // Our custom protocol loop.
        // We expect the client to either start a transaction with regular queries
        // or issue commands for our sharding and server selection protocol.
@@ -763,13 +783,16 @@ where
                self.transaction_mode
            );

+            // Should we rewrite prepared statements and bind messages?
+            let mut prepared_statements_enabled = get_prepared_statements();
+
            // Read a complete message from the client, which normally would be
            // either a `Q` (query) or `P` (prepare, extended protocol).
            // We can parse it here before grabbing a server from the pool,
            // in case the client is sending some custom protocol messages, e.g.
            // SET SHARDING KEY TO 'bigint';

-            let message = tokio::select! {
+            let mut message = tokio::select! {
                _ = self.shutdown.recv() => {
                    if !self.admin {
                        error_response_terminal(
@@ -797,28 +820,75 @@ where
                // allocate a connection, we wouldn't be able to send back an error message
                // to the client so we buffer them and defer the decision to error out or not
                // to when we get the S message
-                'D' | 'E' => {
+                'D' => {
+                    if prepared_statements_enabled {
+                        let name;
+                        (name, message) = self.rewrite_describe(message).await?;
+
+                        if let Some(name) = name {
+                            prepared_statement = Some(name);
+                        }
+                    }
+
+                    self.buffer.put(&message[..]);
+                    continue;
+                }
+
+                'E' => {
                    self.buffer.put(&message[..]);
                    continue;
                }

                'Q' => {
                    if query_router.query_parser_enabled() {
-                        query_router.infer(&message);
+                        if let Ok(ast) = QueryRouter::parse(&message) {
+                            let plugin_result = query_router.execute_plugins(&ast).await;
+
+                            match plugin_result {
+                                Ok(PluginOutput::Deny(error)) => {
+                                    error_response(&mut self.write, &error).await?;
+                                    continue;
+                                }
+
+                                Ok(PluginOutput::Intercept(result)) => {
+                                    write_all(&mut self.write, result).await?;
+                                    continue;
+                                }
+
+                                _ => (),
+                            };
+
+                            let _ = query_router.infer(&ast);
+                        }
                    }
                }

                'P' => {
+                    if prepared_statements_enabled {
+                        (prepared_statement, message) = self.rewrite_parse(message)?;
+                        will_prepare = true;
+                    }
+
                    self.buffer.put(&message[..]);

                    if query_router.query_parser_enabled() {
-                        query_router.infer(&message);
+                        if let Ok(ast) = QueryRouter::parse(&message) {
+                            if let Ok(output) = query_router.execute_plugins(&ast).await {
+                                plugin_output = Some(output);
+                            }
+
+                            let _ = query_router.infer(&ast);
+                        }
                    }

                    continue;
                }

                'B' => {
+                    if prepared_statements_enabled {
+                        (prepared_statement, message) = self.rewrite_bind(message).await?;
+                    }
+
                    self.buffer.put(&message[..]);

                    if query_router.query_parser_enabled() {
@@ -846,6 +916,18 @@ where
                continue;
            }

+            // Check on plugin results.
+            match plugin_output {
+                Some(PluginOutput::Deny(error)) => {
+                    self.buffer.clear();
+                    error_response(&mut self.write, &error).await?;
+                    plugin_output = None;
+                    continue;
+                }
+
+                _ => (),
+            };
+
            // Get a pool instance referenced by the most up-to-date
            // pointer. This ensures we always read the latest config
            // when starting a query.
@@ -1015,7 +1097,48 @@ where
            // If the client is in session mode, no more custom protocol
            // commands will be accepted.
            loop {
-                let message = match initial_message {
+                // Only check if we should rewrite prepared statements
+                // in session mode. In transaction mode, we check at the beginning of
+                // each transaction.
+                if !self.transaction_mode {
+                    prepared_statements_enabled = get_prepared_statements();
+                }
+
+                debug!("Prepared statement active: {:?}", prepared_statement);
+
+                // We are processing a prepared statement.
+                if let Some(ref name) = prepared_statement {
+                    debug!("Checking prepared statement is on server");
+                    // Get the prepared statement the server expects to see.
+                    let statement = match self.prepared_statements.get(name) {
+                        Some(statement) => {
+                            debug!("Prepared statement `{}` found in cache", name);
+                            statement
+                        }
+                        None => {
+                            return Err(Error::ClientError(format!(
+                                "prepared statement `{}` not found",
+                                name
+                            )))
+                        }
+                    };
+
+                    // Since it's already in the buffer, we don't need to prepare it on this server.
+                    if will_prepare {
+                        server.will_prepare(&statement.name);
+                        will_prepare = false;
+                    } else {
+                        // The statement is not prepared on the server, so we need to prepare it.
+                        if server.should_prepare(&statement.name) {
+                            server.prepare(statement).await?;
+                        }
+                    }
+
+                    // Done processing the prepared statement.
+                    prepared_statement = None;
+                }
+
+                let mut message = match initial_message {
                    None => {
                        trace!("Waiting for message inside transaction or in session mode");

@@ -1074,6 +1197,27 @@ where
                match code {
                    // Query
                    'Q' => {
+                        if query_router.query_parser_enabled() {
+                            if let Ok(ast) = QueryRouter::parse(&message) {
+                                let plugin_result = query_router.execute_plugins(&ast).await;
+
+                                match plugin_result {
+                                    Ok(PluginOutput::Deny(error)) => {
+                                        error_response(&mut self.write, &error).await?;
+                                        continue;
+                                    }
+
+                                    Ok(PluginOutput::Intercept(result)) => {
+                                        write_all(&mut self.write, result).await?;
+                                        continue;
+                                    }
+
+                                    _ => (),
+                                };
+
+                                let _ = query_router.infer(&ast);
+                            }
+                        }
                        debug!("Sending query to server");

                        self.send_and_receive_loop(
@@ -1113,18 +1257,44 @@ where
                    // Parse
                    // The query with placeholders is here, e.g. `SELECT * FROM users WHERE email = $1 AND active = $2`.
                    'P' => {
+                        if prepared_statements_enabled {
+                            (prepared_statement, message) = self.rewrite_parse(message)?;
+                            will_prepare = true;
+                        }
+
+                        if query_router.query_parser_enabled() {
+                            if let Ok(ast) = QueryRouter::parse(&message) {
+                                if let Ok(output) = query_router.execute_plugins(&ast).await {
+                                    plugin_output = Some(output);
+                                }
+                            }
+                        }
+
                        self.buffer.put(&message[..]);
                    }

                    // Bind
                    // The placeholder's replacements are here, e.g. 'user@email.com' and 'true'
                    'B' => {
+                        if prepared_statements_enabled {
+                            (prepared_statement, message) = self.rewrite_bind(message).await?;
+                        }
+
                        self.buffer.put(&message[..]);
                    }

                    // Describe
                    // Command a client can issue to describe a previously prepared named statement.
                    'D' => {
+                        if prepared_statements_enabled {
+                            let name;
+                            (name, message) = self.rewrite_describe(message).await?;
+
+                            if let Some(name) = name {
+                                prepared_statement = Some(name);
+                            }
+                        }
+
                        self.buffer.put(&message[..]);
                    }

@@ -1144,12 +1314,30 @@ where
                    'S' => {
                        debug!("Sending query to server");

+                        match plugin_output {
+                            Some(PluginOutput::Deny(error)) => {
+                                error_response(&mut self.write, &error).await?;
+                                plugin_output = None;
+                                self.buffer.clear();
+                                continue;
+                            }
+
+                            Some(PluginOutput::Intercept(result)) => {
+                                write_all(&mut self.write, result).await?;
+                                plugin_output = None;
+                                self.buffer.clear();
+                                continue;
+                            }
+
+                            _ => (),
+                        };
+
                        self.buffer.put(&message[..]);

                        let first_message_code = (*self.buffer.get(0).unwrap_or(&0)) as char;

                        // Almost certainly true
-                        if first_message_code == 'P' {
+                        if first_message_code == 'P' && !prepared_statements_enabled {
                            // Message layout
                            // P followed by 32 int followed by null-terminated statement name
                            // So message code should be in offset 0 of the buffer, first character
@@ -1215,7 +1403,7 @@ where
                            .receive_server_message(server, &address, &pool, &self.stats.clone())
                            .await?;

-                        match write_all_half(&mut self.write, &response).await {
+                        match write_all_flush(&mut self.write, &response).await {
                            Ok(_) => (),
                            Err(err) => {
                                server.mark_bad();
@@ -1277,6 +1465,107 @@ where
        }
    }

+    /// Rewrite Parse (F) message to set the prepared statement name to one we control.
+    /// Save it into the client cache.
+    fn rewrite_parse(&mut self, message: BytesMut) -> Result<(Option<String>, BytesMut), Error> {
+        let parse: Parse = (&message).try_into()?;
+
+        let name = parse.name.clone();
+
+        // Don't rewrite anonymous prepared statements
+        if parse.anonymous() {
+            debug!("Anonymous prepared statement");
+            return Ok((None, message));
+        }
+
+        let parse = parse.rename();
+
+        debug!(
+            "Renamed prepared statement `{}` to `{}` and saved to cache",
+            name, parse.name
+        );
+
+        self.prepared_statements.insert(name.clone(), parse.clone());
+
+        Ok((Some(name), parse.try_into()?))
+    }
+
+    /// Rewrite the Bind (F) message to use the prepared statement name
+    /// saved in the client cache.
+    async fn rewrite_bind(
+        &mut self,
+        message: BytesMut,
+    ) -> Result<(Option<String>, BytesMut), Error> {
+        let bind: Bind = (&message).try_into()?;
+        let name = bind.prepared_statement.clone();
+
+        if bind.anonymous() {
+            debug!("Anonymous bind message");
+            return Ok((None, message));
+        }
+
+        match self.prepared_statements.get(&name) {
+            Some(prepared_stmt) => {
+                let bind = bind.reassign(prepared_stmt);
+
+                debug!("Rewrote bind `{}` to `{}`", name, bind.prepared_statement);
+
+                Ok((Some(name), bind.try_into()?))
+            }
+            None => {
+                debug!("Got bind for unknown prepared statement {:?}", bind);
+
+                error_response(
+                    &mut self.write,
+                    &format!(
+                        "prepared statement \"{}\" does not exist",
+                        bind.prepared_statement
+                    ),
+                )
+                .await?;
+
+                Err(Error::ClientError(format!(
+                    "Prepared statement `{}` doesn't exist",
+                    name
+                )))
+            }
+        }
+    }
+
+    /// Rewrite the Describe (F) message to use the prepared statement name
+    /// saved in the client cache.
+    async fn rewrite_describe(
+        &mut self,
+        message: BytesMut,
+    ) -> Result<(Option<String>, BytesMut), Error> {
+        let describe: Describe = (&message).try_into()?;
+        let name = describe.statement_name.clone();
+
+        if describe.anonymous() {
+            debug!("Anonymous describe");
+            return Ok((None, message));
+        }
+
+        match self.prepared_statements.get(&name) {
+            Some(prepared_stmt) => {
+                let describe = describe.rename(&prepared_stmt.name);
+
+                debug!(
+                    "Rewrote describe `{}` to `{}`",
+                    name, describe.statement_name
+                );
+
+                Ok((Some(name), describe.try_into()?))
+            }
+
+            None => {
+                debug!("Got describe for unknown prepared statement {:?}", describe);
+
+                Ok((None, message))
+            }
+        }
+    }
+
    /// Release the server from the client: it can't cancel its queries anymore.
    pub fn release(&self) {
        let mut guard = self.client_server_map.lock();
@@ -1310,7 +1599,7 @@ where
                .receive_server_message(server, address, pool, client_stats)
                .await?;

-            match write_all_half(&mut self.write, &response).await {
+            match write_all_flush(&mut self.write, &response).await {
                Ok(_) => (),
                Err(err) => {
                    server.mark_bad();
--- a/src/config.rs
+++ b/src/config.rs
@@ -12,6 +12,7 @@ use std::sync::Arc;
 use tokio::fs::File;
 use tokio::io::AsyncReadExt;

+use crate::dns_cache::CachedResolver;
 use crate::errors::Error;
 use crate::pool::{ClientServerMap, ConnectionPool};
 use crate::sharding::ShardingFunction;
@@ -121,6 +122,16 @@ impl Default for Address {
    }
 }

+impl std::fmt::Display for Address {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "[address: {}:{}][database: {}][user: {}]",
+            self.host, self.port, self.database, self.username
+        )
+    }
+}
+
 // We need to implement PartialEq by ourselves so we skip stats in the comparison
 impl PartialEq for Address {
    fn eq(&self, other: &Self) -> bool {
@@ -181,7 +192,9 @@ pub struct User {
    pub server_username: Option<String>,
    pub server_password: Option<String>,
    pub pool_size: u32,
+    pub min_pool_size: Option<u32>,
    pub pool_mode: Option<PoolMode>,
+    pub server_lifetime: Option<u64>,
    #[serde(default)] // 0
    pub statement_timeout: u64,
 }
@@ -194,12 +207,34 @@ impl Default for User {
            server_username: None,
            server_password: None,
            pool_size: 15,
+            min_pool_size: None,
            statement_timeout: 0,
            pool_mode: None,
+            server_lifetime: None,
        }
    }
 }

+impl User {
+    fn validate(&self) -> Result<(), Error> {
+        match self.min_pool_size {
+            Some(min_pool_size) => {
+                if min_pool_size > self.pool_size {
+                    error!(
+                        "min_pool_size of {} cannot be larger than pool_size of {}",
+                        min_pool_size, self.pool_size
+                    );
+                    return Err(Error::BadConfig);
+                }
+            }
+
+            None => (),
+        };
+
+        Ok(())
+    }
+}
+
 /// General configuration.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct General {
@@ -210,6 +245,8 @@ pub struct General {
    pub port: u16,

    pub enable_prometheus_exporter: Option<bool>,
+
+    #[serde(default = "General::default_prometheus_exporter_port")]
    pub prometheus_exporter_port: i16,

    #[serde(default = "General::default_connect_timeout")]
@@ -231,6 +268,12 @@ pub struct General {
    #[serde(default)] // False
    pub log_client_disconnections: bool,

+    #[serde(default)] // False
+    pub dns_cache_enabled: bool,
+
+    #[serde(default = "General::default_dns_max_ttl")]
+    pub dns_max_ttl: u64,
+
    #[serde(default = "General::default_shutdown_timeout")]
    pub shutdown_timeout: u64,

@@ -246,6 +289,12 @@ pub struct General {
    #[serde(default = "General::default_idle_client_in_transaction_timeout")]
    pub idle_client_in_transaction_timeout: u64,

+    #[serde(default = "General::default_server_lifetime")]
+    pub server_lifetime: u64,
+
+    #[serde(default = "General::default_server_round_robin")] // False
+    pub server_round_robin: bool,
+
    #[serde(default = "General::default_worker_threads")]
    pub worker_threads: usize,

@@ -254,12 +303,26 @@ pub struct General {

    pub tls_certificate: Option<String>,
    pub tls_private_key: Option<String>,
+
+    #[serde(default)] // false
+    pub server_tls: bool,
+
+    #[serde(default)] // false
+    pub verify_server_certificate: bool,
+
    pub admin_username: String,
    pub admin_password: String,

+    #[serde(default = "General::default_validate_config")]
+    pub validate_config: bool,
+
+    // Support for auth query
    pub auth_query: Option<String>,
    pub auth_query_user: Option<String>,
    pub auth_query_password: Option<String>,
+
+    #[serde(default)]
+    pub prepared_statements: bool,
 }

 impl General {
@@ -271,6 +334,10 @@ impl General {
        5432
    }

+    pub fn default_server_lifetime() -> u64 {
+        1000 * 60 * 60 // 1 hour
+    }
+
    pub fn default_connect_timeout() -> u64 {
        1000
    }
@@ -291,13 +358,17 @@ impl General {
    }

    pub fn default_idle_timeout() -> u64 {
-        60000 // 10 minutes
+        600000 // 10 minutes
    }

    pub fn default_shutdown_timeout() -> u64 {
        60000
    }

+    pub fn default_dns_max_ttl() -> u64 {
+        30
+    }
+
    pub fn default_healthcheck_timeout() -> u64 {
        1000
    }
@@ -317,6 +388,18 @@ impl General {
    pub fn default_idle_client_in_transaction_timeout() -> u64 {
        0
    }
+
+    pub fn default_validate_config() -> bool {
+        true
+    }
+
+    pub fn default_prometheus_exporter_port() -> i16 {
+        9930
+    }
+
+    pub fn default_server_round_robin() -> bool {
+        true
+    }
 }

 impl Default for General {
@@ -340,13 +423,21 @@ impl Default for General {
            log_client_connections: false,
            log_client_disconnections: false,
            autoreload: None,
+            dns_cache_enabled: false,
+            dns_max_ttl: Self::default_dns_max_ttl(),
            tls_certificate: None,
            tls_private_key: None,
+            server_tls: false,
+            verify_server_certificate: false,
            admin_username: String::from("admin"),
            admin_password: String::from("admin"),
            auth_query: None,
            auth_query_user: None,
            auth_query_password: None,
+            server_lifetime: Self::default_server_lifetime(),
+            server_round_robin: false,
+            validate_config: true,
+            prepared_statements: false,
        }
    }
 }
@@ -399,6 +490,7 @@ pub struct Pool {
    #[serde(default = "Pool::default_load_balancing_mode")]
    pub load_balancing_mode: LoadBalancingMode,

+    #[serde(default = "Pool::default_default_role")]
    pub default_role: String,

    #[serde(default)] // False
@@ -407,10 +499,18 @@ pub struct Pool {
    #[serde(default)] // False
    pub primary_reads_enabled: bool,

+    /// Maximum time to allow for establishing a new server connection.
    pub connect_timeout: Option<u64>,

+    /// Close idle connections that have been opened for longer than this.
    pub idle_timeout: Option<u64>,

+    /// Close server connections that have been opened for longer than this.
+    /// Only applied to idle connections. If the connection is actively used for
+    /// longer than this period, the pool will not interrupt it.
+    pub server_lifetime: Option<u64>,
+
+    #[serde(default = "Pool::default_sharding_function")]
    pub sharding_function: ShardingFunction,

    #[serde(default = "Pool::default_automatic_sharding_key")]
@@ -424,6 +524,10 @@ pub struct Pool {
    pub auth_query_user: Option<String>,
    pub auth_query_password: Option<String>,

+    #[serde(default = "Pool::default_cleanup_server_connections")]
+    pub cleanup_server_connections: bool,
+
+    pub plugins: Option<Plugins>,
    pub shards: BTreeMap<String, Shard>,
    pub users: BTreeMap<String, User>,
    // Note, don't put simple fields below these configs. There's a compatibility issue with TOML that makes it
@@ -456,6 +560,18 @@ impl Pool {
        None
    }

+    pub fn default_default_role() -> String {
+        "any".into()
+    }
+
+    pub fn default_sharding_function() -> ShardingFunction {
+        ShardingFunction::PgBigintHash
+    }
+
+    pub fn default_cleanup_server_connections() -> bool {
+        true
+    }
+
    pub fn validate(&mut self) -> Result<(), Error> {
        match self.default_role.as_ref() {
            "any" => (),
@@ -515,6 +631,10 @@ impl Pool {
            None => None,
        };

+        for (_, user) in &self.users {
+            user.validate()?;
+        }
+
        Ok(())
    }
 }
@@ -539,6 +659,9 @@ impl Default for Pool {
            auth_query: None,
            auth_query_user: None,
            auth_query_password: None,
+            server_lifetime: None,
+            plugins: None,
+            cleanup_server_connections: true,
        }
    }
 }
@@ -588,7 +711,7 @@ impl Shard {

        if primary_count > 1 {
            error!(
-                "Shard {} has more than on primary configured",
+                "Shard {} has more than one primary configured",
                self.database
            );
            return Err(Error::BadConfig);
@@ -617,6 +740,76 @@ impl Default for Shard {
    }
 }

+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct Plugins {
+    pub intercept: Option<Intercept>,
+    pub table_access: Option<TableAccess>,
+    pub query_logger: Option<QueryLogger>,
+    pub prewarmer: Option<Prewarmer>,
+}
+
+impl std::fmt::Display for Plugins {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "interceptor: {}, table_access: {}, query_logger: {}, prewarmer: {}",
+            self.intercept.is_some(),
+            self.table_access.is_some(),
+            self.query_logger.is_some(),
+            self.prewarmer.is_some(),
+        )
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct Intercept {
+    pub enabled: bool,
+    pub queries: BTreeMap<String, Query>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct TableAccess {
+    pub enabled: bool,
+    pub tables: Vec<String>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct QueryLogger {
+    pub enabled: bool,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct Prewarmer {
+    pub enabled: bool,
+    pub queries: Vec<String>,
+}
+
+impl Intercept {
+    pub fn substitute(&mut self, db: &str, user: &str) {
+        for (_, query) in self.queries.iter_mut() {
+            query.substitute(db, user);
+            query.query = query.query.to_ascii_lowercase();
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, Hash, Eq)]
+pub struct Query {
+    pub query: String,
+    pub schema: Vec<Vec<String>>,
+    pub result: Vec<Vec<String>>,
+}
+
+impl Query {
+    pub fn substitute(&mut self, db: &str, user: &str) {
+        for col in self.result.iter_mut() {
+            for i in 0..col.len() {
+                col[i] = col[i].replace("${USER}", user).replace("${DATABASE}", db);
+            }
+        }
+    }
+}
+
 /// Configuration wrapper.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct Config {
@@ -634,7 +827,13 @@ pub struct Config {
    #[serde(default = "Config::default_path")]
    pub path: String,

+    // General and global settings.
    pub general: General,
+
+    // Plugins that should run in all pools.
+    pub plugins: Option<Plugins>,
+
+    // Connection pools.
    pub pools: HashMap<String, Pool>,
 }

@@ -672,6 +871,7 @@ impl Default for Config {
            path: Self::default_path(),
            general: General::default(),
            pools: HashMap::default(),
+            plugins: None,
        }
    }
 }
@@ -791,6 +991,11 @@ impl Config {
        );
        info!("Shutdown timeout: {}ms", self.general.shutdown_timeout);
        info!("Healthcheck delay: {}ms", self.general.healthcheck_delay);
+        info!(
+            "Default max server lifetime: {}ms",
+            self.general.server_lifetime
+        );
+        info!("Sever round robin: {}", self.general.server_round_robin);
        match self.general.tls_certificate.clone() {
            Some(tls_certificate) => {
                info!("TLS certificate: {}", tls_certificate);
@@ -809,6 +1014,19 @@ impl Config {
                info!("TLS support is disabled");
            }
        };
+        info!("Server TLS enabled: {}", self.general.server_tls);
+        info!(
+            "Server TLS certificate verification: {}",
+            self.general.verify_server_certificate
+        );
+        info!("Prepared statements: {}", self.general.prepared_statements);
+        info!(
+            "Plugins: {}",
+            match self.plugins {
+                Some(ref plugins) => plugins.to_string(),
+                None => "not configured".into(),
+            }
+        );

        for (pool_name, pool_config) in &self.pools {
            // TODO: Make this output prettier (maybe a table?)
@@ -867,12 +1085,38 @@ impl Config {
                pool_name,
                pool_config.users.len()
            );
+            info!(
+                "[pool: {}] Max server lifetime: {}",
+                pool_name,
+                match pool_config.server_lifetime {
+                    Some(server_lifetime) => format!("{}ms", server_lifetime),
+                    None => "default".to_string(),
+                }
+            );
+            info!(
+                "[pool: {}] Cleanup server connections: {}",
+                pool_name, pool_config.cleanup_server_connections
+            );
+            info!(
+                "[pool: {}] Plugins: {}",
+                pool_name,
+                match pool_config.plugins {
+                    Some(ref plugins) => plugins.to_string(),
+                    None => "not configured".into(),
+                }
+            );

            for user in &pool_config.users {
                info!(
                    "[pool: {}][user: {}] Pool size: {}",
                    pool_name, user.1.username, user.1.pool_size,
                );
+                info!(
+                    "[pool: {}][user: {}] Minimum pool size: {}",
+                    pool_name,
+                    user.1.username,
+                    user.1.min_pool_size.unwrap_or(0)
+                );
                info!(
                    "[pool: {}][user: {}] Statement timeout: {}",
                    pool_name, user.1.username, user.1.statement_timeout
@@ -886,6 +1130,15 @@ impl Config {
                        None => pool_config.pool_mode.to_string(),
                    }
                );
+                info!(
+                    "[pool: {}][user: {}] Max server lifetime: {}",
+                    pool_name,
+                    user.1.username,
+                    match user.1.server_lifetime {
+                        Some(server_lifetime) => format!("{}ms", server_lifetime),
+                        None => "default".to_string(),
+                    }
+                );
            }
        }
    }
@@ -896,7 +1149,13 @@ impl Config {
            && (self.general.auth_query_user.is_none()
                || self.general.auth_query_password.is_none())
        {
-            error!("If auth_query is specified, you need to provide a value for `auth_query_user`, `auth_query_password`");
+            error!(
+                "If auth_query is specified, \
+                you need to provide a value \
+                for `auth_query_user`, \
+                `auth_query_password`"
+            );
+
            return Err(Error::BadConfig);
        }

@@ -904,7 +1163,14 @@ impl Config {
            if pool.auth_query.is_some()
                && (pool.auth_query_user.is_none() || pool.auth_query_password.is_none())
            {
-                error!("Error in pool {{ {} }}. If auth_query is specified, you need to provide a value for `auth_query_user`, `auth_query_password`", name);
+                error!(
+                    "Error in pool {{ {} }}. \
+                    If auth_query is specified, you need \
+                    to provide a value for `auth_query_user`, \
+                    `auth_query_password`",
+                    name
+                );
+
                return Err(Error::BadConfig);
            }

@@ -914,7 +1180,13 @@ impl Config {
                    || pool.auth_query_user.is_none())
                    && user_data.password.is_none()
                {
-                    error!("Error in pool {{ {} }}. You have to specify a user password for every pool if auth_query is not specified", name);
+                    error!(
+                        "Error in pool {{ {} }}. \
+                        You have to specify a user password \
+                        for every pool if auth_query is not specified",
+                        name
+                    );
+
                    return Err(Error::BadConfig);
                }
            }
@@ -972,6 +1244,10 @@ pub fn get_idle_client_in_transaction_timeout() -> u64 {
        .idle_client_in_transaction_timeout
 }

+pub fn get_prepared_statements() -> bool {
+    (*(*CONFIG.load())).general.prepared_statements
+}
+
 /// Parse the configuration file located at the path.
 pub async fn parse(path: &str) -> Result<(), Error> {
    let mut contents = String::new();
@@ -1012,6 +1288,7 @@ pub async fn parse(path: &str) -> Result<(), Error> {

 pub async fn reload_config(client_server_map: ClientServerMap) -> Result<bool, Error> {
    let old_config = get_config();
+
    match parse(&old_config.path).await {
        Ok(()) => (),
        Err(err) => {
@@ -1019,14 +1296,18 @@ pub async fn reload_config(client_server_map: ClientServerMap) -> Result<bool, E
            return Err(Error::BadConfig);
        }
    };
+
    let new_config = get_config();

-    if old_config.pools != new_config.pools {
-        info!("Pool configuration changed");
+    match CachedResolver::from_config().await {
+        Ok(_) => (),
+        Err(err) => error!("DNS cache reinitialization error: {:?}", err),
+    };
+
+    if old_config != new_config {
+        info!("Config changed, reloading");
        ConnectionPool::from_config(client_server_map).await?;
        Ok(true)
-    } else if old_config != new_config {
-        Ok(true)
    } else {
        Ok(false)
    }
--- a/src/dns_cache.rs
+++ b/src/dns_cache.rs
@@ -0,0 +1,410 @@
+use crate::config::get_config;
+use crate::errors::Error;
+use arc_swap::ArcSwap;
+use log::{debug, error, info, warn};
+use once_cell::sync::Lazy;
+use std::collections::{HashMap, HashSet};
+use std::io;
+use std::net::IpAddr;
+use std::sync::Arc;
+use std::sync::RwLock;
+use tokio::time::{sleep, Duration};
+use trust_dns_resolver::error::{ResolveError, ResolveResult};
+use trust_dns_resolver::lookup_ip::LookupIp;
+use trust_dns_resolver::TokioAsyncResolver;
+
+/// Cached Resolver Globally available
+pub static CACHED_RESOLVER: Lazy<ArcSwap<CachedResolver>> =
+    Lazy::new(|| ArcSwap::from_pointee(CachedResolver::default()));
+
+// Ip addressed are returned as a set of addresses
+// so we can compare.
+#[derive(Clone, PartialEq, Debug)]
+pub struct AddrSet {
+    set: HashSet<IpAddr>,
+}
+
+impl AddrSet {
+    fn new() -> AddrSet {
+        AddrSet {
+            set: HashSet::new(),
+        }
+    }
+}
+
+impl From<LookupIp> for AddrSet {
+    fn from(lookup_ip: LookupIp) -> Self {
+        let mut addr_set = AddrSet::new();
+        for address in lookup_ip.iter() {
+            addr_set.set.insert(address);
+        }
+        addr_set
+    }
+}
+
+///
+/// A CachedResolver is a DNS resolution cache mechanism with customizable expiration time.
+///
+/// The system works as follows:
+///
+/// When a host is to be resolved, if we have not resolved it before, a new resolution is
+/// executed and stored in the internal cache. Concurrently, every `dns_max_ttl` time, the
+/// cache is refreshed.
+///
+/// # Example:
+///
+/// ```
+/// use pgcat::dns_cache::{CachedResolverConfig, CachedResolver};
+///
+/// # tokio_test::block_on(async {
+/// let config = CachedResolverConfig::default();
+/// let resolver = CachedResolver::new(config, None).await.unwrap();
+/// let addrset = resolver.lookup_ip("www.example.com.").await.unwrap();
+/// # })
+/// ```
+///
+/// // Now the ip resolution is stored in local cache and subsequent
+/// // calls will be returned from cache. Also, the cache is refreshed
+/// // and updated every 10 seconds.
+///
+/// // You can now check if an 'old' lookup differs from what it's currently
+/// // store in cache by using `has_changed`.
+/// resolver.has_changed("www.example.com.", addrset)
+#[derive(Default)]
+pub struct CachedResolver {
+    // The configuration of the cached_resolver.
+    config: CachedResolverConfig,
+
+    // This is the hash that contains the hash.
+    data: Option<RwLock<HashMap<String, AddrSet>>>,
+
+    // The resolver to be used for DNS queries.
+    resolver: Option<TokioAsyncResolver>,
+
+    // The RefreshLoop
+    refresh_loop: RwLock<Option<tokio::task::JoinHandle<()>>>,
+}
+
+///
+/// Configuration
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct CachedResolverConfig {
+    /// Amount of time in secods that a resolved dns address is considered stale.
+    dns_max_ttl: u64,
+
+    /// Enabled or disabled? (this is so we can reload config)
+    enabled: bool,
+}
+
+impl CachedResolverConfig {
+    fn new(dns_max_ttl: u64, enabled: bool) -> Self {
+        CachedResolverConfig {
+            dns_max_ttl,
+            enabled,
+        }
+    }
+}
+
+impl From<crate::config::Config> for CachedResolverConfig {
+    fn from(config: crate::config::Config) -> Self {
+        CachedResolverConfig::new(config.general.dns_max_ttl, config.general.dns_cache_enabled)
+    }
+}
+
+impl CachedResolver {
+    ///
+    /// Returns a new Arc<CachedResolver> based on passed configuration.
+    /// It also starts the loop that will refresh cache entries.
+    ///
+    /// # Arguments:
+    ///
+    /// * `config` - The `CachedResolverConfig` to be used to create the resolver.
+    ///
+    /// # Example:
+    ///
+    /// ```
+    /// use pgcat::dns_cache::{CachedResolverConfig, CachedResolver};
+    ///
+    /// # tokio_test::block_on(async {
+    /// let config = CachedResolverConfig::default();
+    /// let resolver = CachedResolver::new(config, None).await.unwrap();
+    /// # })
+    /// ```
+    ///
+    pub async fn new(
+        config: CachedResolverConfig,
+        data: Option<HashMap<String, AddrSet>>,
+    ) -> Result<Arc<Self>, io::Error> {
+        // Construct a new Resolver with default configuration options
+        let resolver = Some(TokioAsyncResolver::tokio_from_system_conf()?);
+
+        let data = if let Some(hash) = data {
+            Some(RwLock::new(hash))
+        } else {
+            Some(RwLock::new(HashMap::new()))
+        };
+
+        let instance = Arc::new(Self {
+            config,
+            resolver,
+            data,
+            refresh_loop: RwLock::new(None),
+        });
+
+        if instance.enabled() {
+            info!("Scheduling DNS refresh loop");
+            let refresh_loop = tokio::task::spawn({
+                let instance = instance.clone();
+                async move {
+                    instance.refresh_dns_entries_loop().await;
+                }
+            });
+            *(instance.refresh_loop.write().unwrap()) = Some(refresh_loop);
+        }
+
+        Ok(instance)
+    }
+
+    pub fn enabled(&self) -> bool {
+        self.config.enabled
+    }
+
+    // Schedules the refresher
+    async fn refresh_dns_entries_loop(&self) {
+        let resolver = TokioAsyncResolver::tokio_from_system_conf().unwrap();
+        let interval = Duration::from_secs(self.config.dns_max_ttl);
+        loop {
+            debug!("Begin refreshing cached DNS addresses.");
+            // To minimize the time we hold the lock, we first create
+            // an array with keys.
+            let mut hostnames: Vec<String> = Vec::new();
+            {
+                if let Some(ref data) = self.data {
+                    for hostname in data.read().unwrap().keys() {
+                        hostnames.push(hostname.clone());
+                    }
+                }
+            }
+
+            for hostname in hostnames.iter() {
+                let addrset = self
+                    .fetch_from_cache(hostname.as_str())
+                    .expect("Could not obtain expected address from cache, this should not happen");
+
+                match resolver.lookup_ip(hostname).await {
+                    Ok(lookup_ip) => {
+                        let new_addrset = AddrSet::from(lookup_ip);
+                        debug!(
+                            "Obtained address for host ({}) -> ({:?})",
+                            hostname, new_addrset
+                        );
+
+                        if addrset != new_addrset {
+                            debug!(
+                                "Addr changed from {:?} to {:?} updating cache.",
+                                addrset, new_addrset
+                            );
+                            self.store_in_cache(hostname, new_addrset);
+                        }
+                    }
+                    Err(err) => {
+                        error!(
+                            "There was an error trying to resolv {}: ({}).",
+                            hostname, err
+                        );
+                    }
+                }
+            }
+            debug!("Finished refreshing cached DNS addresses.");
+            sleep(interval).await;
+        }
+    }
+
+    /// Returns a `AddrSet` given the specified hostname.
+    ///
+    /// This method first tries to fetch the value from the cache, if it misses
+    /// then it is resolved and stored in the cache. TTL from records is ignored.
+    ///
+    /// # Arguments
+    ///
+    /// * `host`      - A string slice referencing the hostname to be resolved.
+    ///
+    /// # Example:
+    ///
+    /// ```
+    /// use pgcat::dns_cache::{CachedResolverConfig, CachedResolver};
+    ///
+    /// # tokio_test::block_on(async {
+    /// let config = CachedResolverConfig::default();
+    /// let resolver = CachedResolver::new(config, None).await.unwrap();
+    /// let response = resolver.lookup_ip("www.google.com.");
+    /// # })
+    /// ```
+    ///
+    pub async fn lookup_ip(&self, host: &str) -> ResolveResult<AddrSet> {
+        debug!("Lookup up {} in cache", host);
+        match self.fetch_from_cache(host) {
+            Some(addr_set) => {
+                debug!("Cache hit!");
+                Ok(addr_set)
+            }
+            None => {
+                debug!("Not found, executing a dns query!");
+                if let Some(ref resolver) = self.resolver {
+                    let addr_set = AddrSet::from(resolver.lookup_ip(host).await?);
+                    debug!("Obtained: {:?}", addr_set);
+                    self.store_in_cache(host, addr_set.clone());
+                    Ok(addr_set)
+                } else {
+                    Err(ResolveError::from("No resolver available"))
+                }
+            }
+        }
+    }
+
+    //
+    // Returns true if the stored host resolution differs from the AddrSet passed.
+    pub fn has_changed(&self, host: &str, addr_set: &AddrSet) -> bool {
+        if let Some(fetched_addr_set) = self.fetch_from_cache(host) {
+            return fetched_addr_set != *addr_set;
+        }
+        false
+    }
+
+    // Fetches an AddrSet from the inner cache adquiring the read lock.
+    fn fetch_from_cache(&self, key: &str) -> Option<AddrSet> {
+        if let Some(ref hash) = self.data {
+            if let Some(addr_set) = hash.read().unwrap().get(key) {
+                return Some(addr_set.clone());
+            }
+        }
+        None
+    }
+
+    // Sets up the global CACHED_RESOLVER static variable so we can globally use DNS
+    // cache.
+    pub async fn from_config() -> Result<(), Error> {
+        let cached_resolver = CACHED_RESOLVER.load();
+        let desired_config = CachedResolverConfig::from(get_config());
+
+        if cached_resolver.config != desired_config {
+            if let Some(ref refresh_loop) = *(cached_resolver.refresh_loop.write().unwrap()) {
+                warn!("Killing Dnscache refresh loop as its configuration is being reloaded");
+                refresh_loop.abort()
+            }
+            let new_resolver = if let Some(ref data) = cached_resolver.data {
+                let data = Some(data.read().unwrap().clone());
+                CachedResolver::new(desired_config, data).await
+            } else {
+                CachedResolver::new(desired_config, None).await
+            };
+
+            match new_resolver {
+                Ok(ok) => {
+                    CACHED_RESOLVER.store(ok);
+                    Ok(())
+                }
+                Err(err) => {
+                    let message = format!("Error setting up cached_resolver. Error: {:?}, will continue without this feature.", err);
+                    Err(Error::DNSCachedError(message))
+                }
+            }
+        } else {
+            Ok(())
+        }
+    }
+
+    // Stores the AddrSet in cache adquiring the write lock.
+    fn store_in_cache(&self, host: &str, addr_set: AddrSet) {
+        if let Some(ref data) = self.data {
+            data.write().unwrap().insert(host.to_string(), addr_set);
+        } else {
+            error!("Could not insert, Hash not initialized");
+        }
+    }
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use trust_dns_resolver::error::ResolveError;
+
+    #[tokio::test]
+    async fn new() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await;
+        assert!(resolver.is_ok());
+    }
+
+    #[tokio::test]
+    async fn lookup_ip() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await.unwrap();
+        let response = resolver.lookup_ip("www.google.com.").await;
+        assert!(response.is_ok());
+    }
+
+    #[tokio::test]
+    async fn has_changed() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await.unwrap();
+        let hostname = "www.google.com.";
+        let response = resolver.lookup_ip(hostname).await;
+        let addr_set = response.unwrap();
+        assert!(!resolver.has_changed(hostname, &addr_set));
+    }
+
+    #[tokio::test]
+    async fn unknown_host() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await.unwrap();
+        let hostname = "www.idontexists.";
+        let response = resolver.lookup_ip(hostname).await;
+        assert!(matches!(response, Err(ResolveError { .. })));
+    }
+
+    #[tokio::test]
+    async fn incorrect_address() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await.unwrap();
+        let hostname = "w  ww.idontexists.";
+        let response = resolver.lookup_ip(hostname).await;
+        assert!(matches!(response, Err(ResolveError { .. })));
+        assert!(!resolver.has_changed(hostname, &AddrSet::new()));
+    }
+
+    #[tokio::test]
+    // Ok, this test is based on the fact that google does DNS RR
+    // and does not responds with every available ip everytime, so
+    // if I cache here, it will miss after one cache iteration or two.
+    async fn thread() {
+        let config = CachedResolverConfig {
+            dns_max_ttl: 10,
+            enabled: true,
+        };
+        let resolver = CachedResolver::new(config, None).await.unwrap();
+        let hostname = "www.google.com.";
+        let response = resolver.lookup_ip(hostname).await;
+        let addr_set = response.unwrap();
+        assert!(!resolver.has_changed(hostname, &addr_set));
+        let resolver_for_refresher = resolver.clone();
+        let _thread_handle = tokio::task::spawn(async move {
+            resolver_for_refresher.refresh_dns_entries_loop().await;
+        });
+        assert!(!resolver.has_changed(hostname, &addr_set));
+    }
+}
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -1,7 +1,7 @@
 //! Errors.

 /// Various errors.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone)]
 pub enum Error {
    SocketError(String),
    ClientSocketError(String, ClientIdentifier),
@@ -19,10 +19,14 @@ pub enum Error {
    ClientError(String),
    TlsError,
    StatementTimeout,
+    DNSCachedError(String),
    ShuttingDown,
    ParseBytesError(String),
    AuthError(String),
    AuthPassthroughError(String),
+    UnsupportedStatement,
+    QueryRouterParserError(String),
+    QueryRouterError(String),
 }

 #[derive(Clone, PartialEq, Debug)]
@@ -118,3 +122,9 @@ impl std::fmt::Display for Error {
        }
    }
 }
+
+impl From<std::ffi::NulError> for Error {
+    fn from(err: std::ffi::NulError) -> Self {
+        Error::QueryRouterError(err.to_string())
+    }
+}
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,11 +1,17 @@
+pub mod admin;
 pub mod auth_passthrough;
+pub mod client;
 pub mod config;
 pub mod constants;
+pub mod dns_cache;
 pub mod errors;
 pub mod messages;
 pub mod mirrors;
 pub mod multi_logger;
+pub mod plugins;
 pub mod pool;
+pub mod prometheus;
+pub mod query_router;
 pub mod scram;
 pub mod server;
 pub mod sharding;
--- a/src/main.rs
+++ b/src/main.rs
@@ -36,6 +36,7 @@ extern crate sqlparser;
 extern crate tokio;
 extern crate tokio_rustls;
 extern crate toml;
+extern crate trust_dns_resolver;

 #[cfg(not(target_env = "msvc"))]
 use jemallocator::Jemalloc;
@@ -60,36 +61,19 @@ use std::str::FromStr;
 use std::sync::Arc;
 use tokio::sync::broadcast;

-mod admin;
-mod auth_passthrough;
-mod client;
-mod config;
-mod constants;
-mod errors;
-mod messages;
-mod mirrors;
-mod multi_logger;
-mod pool;
-mod prometheus;
-mod query_router;
-mod scram;
-mod server;
-mod sharding;
-mod stats;
-mod tls;
-
-use crate::config::{get_config, reload_config, VERSION};
-use crate::messages::configure_socket;
-use crate::pool::{ClientServerMap, ConnectionPool};
-use crate::prometheus::start_metric_server;
-use crate::stats::{Collector, Reporter, REPORTER};
+use pgcat::config::{get_config, reload_config, VERSION};
+use pgcat::dns_cache;
+use pgcat::messages::configure_socket;
+use pgcat::pool::{ClientServerMap, ConnectionPool};
+use pgcat::prometheus::start_metric_server;
+use pgcat::stats::{Collector, Reporter, REPORTER};

 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    multi_logger::MultiLogger::init().unwrap();
+    pgcat::multi_logger::MultiLogger::init().unwrap();

    info!("Welcome to PgCat! Meow. (Version {})", VERSION);

-    if !query_router::QueryRouter::setup() {
+    if !pgcat::query_router::QueryRouter::setup() {
        error!("Could not setup query router");
        std::process::exit(exitcode::CONFIG);
    }
@@ -107,7 +91,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
        let runtime = Builder::new_multi_thread().worker_threads(1).build()?;

        runtime.block_on(async {
-            match config::parse(&config_file).await {
+            match pgcat::config::parse(&config_file).await {
                Ok(_) => (),
                Err(err) => {
                    error!("Config parse error: {:?}", err);
@@ -166,6 +150,12 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
        // Statistics reporting.
        REPORTER.store(Arc::new(Reporter::default()));

+        // Starts (if enabled) dns cache before pools initialization
+        match dns_cache::CachedResolver::from_config().await {
+                Ok(_) => (),
+                Err(err) => error!("DNS cache initialization error: {:?}", err),
+        };
+
        // Connection pool that allows to query all shards and replicas.
        match ConnectionPool::from_config(client_server_map.clone()).await {
            Ok(_) => (),
@@ -295,7 +285,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                    tokio::task::spawn(async move {
                        let start = chrono::offset::Utc::now().naive_utc();

-                        match client::client_entrypoint(
+                        match pgcat::client::client_entrypoint(
                            socket,
                            client_server_map,
                            shutdown_rx,
@@ -326,7 +316,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {

                            Err(err) => {
                                match err {
-                                    errors::Error::ClientBadStartup => debug!("Client disconnected with error {:?}", err),
+                                    pgcat::errors::Error::ClientBadStartup => debug!("Client disconnected with error {:?}", err),
                                    _ => warn!("Client disconnected with error {:?}", err),
                                }

--- a/src/messages.rs
+++ b/src/messages.rs
@@ -7,11 +7,15 @@ use socket2::{SockRef, TcpKeepalive};
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpStream;

+use crate::client::PREPARED_STATEMENT_COUNTER;
 use crate::config::get_config;
 use crate::errors::Error;
+
 use std::collections::HashMap;
+use std::ffi::CString;
 use std::io::{BufRead, Cursor};
 use std::mem;
+use std::sync::atomic::Ordering;
 use std::time::Duration;

 /// Postgres data type mappings
@@ -20,6 +24,10 @@ pub enum DataType {
    Text,
    Int4,
    Numeric,
+    Bool,
+    Oid,
+    AnyArray,
+    Any,
 }

 impl From<&DataType> for i32 {
@@ -28,6 +36,10 @@ impl From<&DataType> for i32 {
            DataType::Text => 25,
            DataType::Int4 => 23,
            DataType::Numeric => 1700,
+            DataType::Bool => 16,
+            DataType::Oid => 26,
+            DataType::AnyArray => 2277,
+            DataType::Any => 2276,
        }
    }
 }
@@ -116,7 +128,10 @@ where

 /// Send the startup packet the server. We're pretending we're a Pg client.
 /// This tells the server which user we are and what database we want.
-pub async fn startup(stream: &mut TcpStream, user: &str, database: &str) -> Result<(), Error> {
+pub async fn startup<S>(stream: &mut S, user: &str, database: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
    let mut bytes = BytesMut::with_capacity(25);

    bytes.put_i32(196608); // Protocol number
@@ -150,6 +165,21 @@ pub async fn startup(stream: &mut TcpStream, user: &str, database: &str) -> Resu
    }
 }

+pub async fn ssl_request(stream: &mut TcpStream) -> Result<(), Error> {
+    let mut bytes = BytesMut::with_capacity(12);
+
+    bytes.put_i32(8);
+    bytes.put_i32(80877103);
+
+    match stream.write_all(&bytes).await {
+        Ok(_) => Ok(()),
+        Err(err) => Err(Error::SocketError(format!(
+            "Error writing SSLRequest to server socket - Error: {:?}",
+            err
+        ))),
+    }
+}
+
 /// Parse the params the server sends as a key/value format.
 pub fn parse_params(mut bytes: BytesMut) -> Result<HashMap<String, String>, Error> {
    let mut result = HashMap::new();
@@ -425,6 +455,10 @@ pub fn row_description(columns: &Vec<(&str, DataType)>) -> BytesMut {
            DataType::Text => -1,
            DataType::Int4 => 4,
            DataType::Numeric => -1,
+            DataType::Bool => 1,
+            DataType::Oid => 4,
+            DataType::AnyArray => -1,
+            DataType::Any => -1,
        };

        row_desc.put_i16(type_size);
@@ -463,6 +497,29 @@ pub fn data_row(row: &Vec<String>) -> BytesMut {
    res
 }

+pub fn data_row_nullable(row: &Vec<Option<String>>) -> BytesMut {
+    let mut res = BytesMut::new();
+    let mut data_row = BytesMut::new();
+
+    data_row.put_i16(row.len() as i16);
+
+    for column in row {
+        if let Some(column) = column {
+            let column = column.as_bytes();
+            data_row.put_i32(column.len() as i32);
+            data_row.put_slice(column);
+        } else {
+            data_row.put_i32(-1 as i32);
+        }
+    }
+
+    res.put_u8(b'D');
+    res.put_i32(data_row.len() as i32 + 4);
+    res.put(data_row);
+
+    res
+}
+
 /// Create a CommandComplete message.
 pub fn command_complete(command: &str) -> BytesMut {
    let cmd = BytesMut::from(format!("{}\0", command).as_bytes());
@@ -473,6 +530,13 @@ pub fn command_complete(command: &str) -> BytesMut {
    res
 }

+pub fn flush() -> BytesMut {
+    let mut bytes = BytesMut::new();
+    bytes.put_u8(b'H');
+    bytes.put_i32(4);
+    bytes
+}
+
 /// Write all data in the buffer to the TcpStream.
 pub async fn write_all<S>(stream: &mut S, buf: BytesMut) -> Result<(), Error>
 where
@@ -505,6 +569,29 @@ where
    }
 }

+pub async fn write_all_flush<S>(stream: &mut S, buf: &[u8]) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
+    match stream.write_all(buf).await {
+        Ok(_) => match stream.flush().await {
+            Ok(_) => Ok(()),
+            Err(err) => {
+                return Err(Error::SocketError(format!(
+                    "Error flushing socket - Error: {:?}",
+                    err
+                )))
+            }
+        },
+        Err(err) => {
+            return Err(Error::SocketError(format!(
+                "Error writing to socket - Error: {:?}",
+                err
+            )))
+        }
+    }
+}
+
 /// Read a complete message from the socket.
 pub async fn read_message<S>(stream: &mut S) -> Result<BytesMut, Error>
 where
@@ -613,3 +700,285 @@ impl BytesMutReader for Cursor<&BytesMut> {
        }
    }
 }
+
+/// Parse (F) message.
+/// See: <https://www.postgresql.org/docs/current/protocol-message-formats.html>
+#[derive(Clone, Debug)]
+pub struct Parse {
+    code: char,
+    #[allow(dead_code)]
+    len: i32,
+    pub name: String,
+    pub generated_name: String,
+    query: String,
+    num_params: i16,
+    param_types: Vec<i32>,
+}
+
+impl TryFrom<&BytesMut> for Parse {
+    type Error = Error;
+
+    fn try_from(buf: &BytesMut) -> Result<Parse, Error> {
+        let mut cursor = Cursor::new(buf);
+        let code = cursor.get_u8() as char;
+        let len = cursor.get_i32();
+        let name = cursor.read_string()?;
+        let query = cursor.read_string()?;
+        let num_params = cursor.get_i16();
+        let mut param_types = Vec::new();
+
+        for _ in 0..num_params {
+            param_types.push(cursor.get_i32());
+        }
+
+        Ok(Parse {
+            code,
+            len,
+            name,
+            generated_name: prepared_statement_name(),
+            query,
+            num_params,
+            param_types,
+        })
+    }
+}
+
+impl TryFrom<Parse> for BytesMut {
+    type Error = Error;
+
+    fn try_from(parse: Parse) -> Result<BytesMut, Error> {
+        let mut bytes = BytesMut::new();
+
+        let name_binding = CString::new(parse.name)?;
+        let name = name_binding.as_bytes_with_nul();
+
+        let query_binding = CString::new(parse.query)?;
+        let query = query_binding.as_bytes_with_nul();
+
+        // Recompute length of the message.
+        let len = 4 // self
+            + name.len()
+            + query.len()
+            + 2
+            + 4 * parse.num_params as usize;
+
+        bytes.put_u8(parse.code as u8);
+        bytes.put_i32(len as i32);
+        bytes.put_slice(name);
+        bytes.put_slice(query);
+        bytes.put_i16(parse.num_params);
+        for param in parse.param_types {
+            bytes.put_i32(param);
+        }
+
+        Ok(bytes)
+    }
+}
+
+impl TryFrom<&Parse> for BytesMut {
+    type Error = Error;
+
+    fn try_from(parse: &Parse) -> Result<BytesMut, Error> {
+        parse.clone().try_into()
+    }
+}
+
+impl Parse {
+    pub fn rename(mut self) -> Self {
+        self.name = self.generated_name.to_string();
+        self
+    }
+
+    pub fn anonymous(&self) -> bool {
+        self.name.is_empty()
+    }
+}
+
+/// Bind (B) message.
+/// See: <https://www.postgresql.org/docs/current/protocol-message-formats.html>
+#[derive(Clone, Debug)]
+pub struct Bind {
+    code: char,
+    #[allow(dead_code)]
+    len: i64,
+    portal: String,
+    pub prepared_statement: String,
+    num_param_format_codes: i16,
+    param_format_codes: Vec<i16>,
+    num_param_values: i16,
+    param_values: Vec<(i32, BytesMut)>,
+    num_result_column_format_codes: i16,
+    result_columns_format_codes: Vec<i16>,
+}
+
+impl TryFrom<&BytesMut> for Bind {
+    type Error = Error;
+
+    fn try_from(buf: &BytesMut) -> Result<Bind, Error> {
+        let mut cursor = Cursor::new(buf);
+        let code = cursor.get_u8() as char;
+        let len = cursor.get_i32();
+        let portal = cursor.read_string()?;
+        let prepared_statement = cursor.read_string()?;
+        let num_param_format_codes = cursor.get_i16();
+        let mut param_format_codes = Vec::new();
+
+        for _ in 0..num_param_format_codes {
+            param_format_codes.push(cursor.get_i16());
+        }
+
+        let num_param_values = cursor.get_i16();
+        let mut param_values = Vec::new();
+
+        for _ in 0..num_param_values {
+            let param_len = cursor.get_i32();
+            let mut param = BytesMut::with_capacity(param_len as usize);
+            param.resize(param_len as usize, b'0');
+            cursor.copy_to_slice(&mut param);
+            param_values.push((param_len, param));
+        }
+
+        let num_result_column_format_codes = cursor.get_i16();
+        let mut result_columns_format_codes = Vec::new();
+
+        for _ in 0..num_result_column_format_codes {
+            result_columns_format_codes.push(cursor.get_i16());
+        }
+
+        Ok(Bind {
+            code,
+            len: len as i64,
+            portal,
+            prepared_statement,
+            num_param_format_codes,
+            param_format_codes,
+            num_param_values,
+            param_values,
+            num_result_column_format_codes,
+            result_columns_format_codes,
+        })
+    }
+}
+
+impl TryFrom<Bind> for BytesMut {
+    type Error = Error;
+
+    fn try_from(bind: Bind) -> Result<BytesMut, Error> {
+        let mut bytes = BytesMut::new();
+
+        let portal_binding = CString::new(bind.portal)?;
+        let portal = portal_binding.as_bytes_with_nul();
+
+        let prepared_statement_binding = CString::new(bind.prepared_statement)?;
+        let prepared_statement = prepared_statement_binding.as_bytes_with_nul();
+
+        let mut len = 4 // self
+            + portal.len()
+            + prepared_statement.len()
+            + 2 // num_param_format_codes
+            + 2 * bind.num_param_format_codes as usize // num_param_format_codes
+            + 2; // num_param_values
+
+        for (param_len, _) in &bind.param_values {
+            len += 4 + *param_len as usize;
+        }
+        len += 2; // num_result_column_format_codes
+        len += 2 * bind.num_result_column_format_codes as usize;
+
+        bytes.put_u8(bind.code as u8);
+        bytes.put_i32(len as i32);
+        bytes.put_slice(portal);
+        bytes.put_slice(prepared_statement);
+        bytes.put_i16(bind.num_param_format_codes);
+        for param_format_code in bind.param_format_codes {
+            bytes.put_i16(param_format_code);
+        }
+        bytes.put_i16(bind.num_param_values);
+        for (param_len, param) in bind.param_values {
+            bytes.put_i32(param_len);
+            bytes.put_slice(&param);
+        }
+        bytes.put_i16(bind.num_result_column_format_codes);
+        for result_column_format_code in bind.result_columns_format_codes {
+            bytes.put_i16(result_column_format_code);
+        }
+
+        Ok(bytes)
+    }
+}
+
+impl Bind {
+    pub fn reassign(mut self, parse: &Parse) -> Self {
+        self.prepared_statement = parse.name.clone();
+        self
+    }
+
+    pub fn anonymous(&self) -> bool {
+        self.prepared_statement.is_empty()
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Describe {
+    code: char,
+
+    #[allow(dead_code)]
+    len: i32,
+    target: char,
+    pub statement_name: String,
+}
+
+impl TryFrom<&BytesMut> for Describe {
+    type Error = Error;
+
+    fn try_from(bytes: &BytesMut) -> Result<Describe, Error> {
+        let mut cursor = Cursor::new(bytes);
+        let code = cursor.get_u8() as char;
+        let len = cursor.get_i32();
+        let target = cursor.get_u8() as char;
+        let statement_name = cursor.read_string()?;
+
+        Ok(Describe {
+            code,
+            len,
+            target,
+            statement_name,
+        })
+    }
+}
+
+impl TryFrom<Describe> for BytesMut {
+    type Error = Error;
+
+    fn try_from(describe: Describe) -> Result<BytesMut, Error> {
+        let mut bytes = BytesMut::new();
+        let statement_name_binding = CString::new(describe.statement_name)?;
+        let statement_name = statement_name_binding.as_bytes_with_nul();
+        let len = 4 + 1 + statement_name.len();
+
+        bytes.put_u8(describe.code as u8);
+        bytes.put_i32(len as i32);
+        bytes.put_u8(describe.target as u8);
+        bytes.put_slice(statement_name);
+
+        Ok(bytes)
+    }
+}
+
+impl Describe {
+    pub fn rename(mut self, name: &str) -> Self {
+        self.statement_name = name.to_string();
+        self
+    }
+
+    pub fn anonymous(&self) -> bool {
+        self.statement_name.is_empty()
+    }
+}
+
+pub fn prepared_statement_name() -> String {
+    format!(
+        "P_{}",
+        PREPARED_STATEMENT_COUNTER.fetch_add(1, Ordering::SeqCst)
+    )
+}
--- a/src/mirrors.rs
+++ b/src/mirrors.rs
@@ -7,8 +7,7 @@ use bytes::{Bytes, BytesMut};
 use parking_lot::RwLock;

 use crate::config::{get_config, Address, Role, User};
-use crate::pool::{ClientServerMap, PoolIdentifier, ServerPool};
-use crate::stats::PoolStats;
+use crate::pool::{ClientServerMap, ServerPool};
 use log::{error, info, trace, warn};
 use tokio::sync::mpsc::{channel, Receiver, Sender};

@@ -24,7 +23,7 @@ impl MirroredClient {
    async fn create_pool(&self) -> Pool<ServerPool> {
        let config = get_config();
        let default = std::time::Duration::from_millis(10_000).as_millis() as u64;
-        let (connection_timeout, idle_timeout, cfg) =
+        let (connection_timeout, idle_timeout, _cfg) =
            match config.pools.get(&self.address.pool_name) {
                Some(cfg) => (
                    cfg.connect_timeout.unwrap_or(default),
@@ -34,15 +33,14 @@ impl MirroredClient {
                None => (default, default, crate::config::Pool::default()),
            };

-        let identifier = PoolIdentifier::new(&self.database, &self.user.username);
-
        let manager = ServerPool::new(
            self.address.clone(),
            self.user.clone(),
            self.database.as_str(),
            ClientServerMap::default(),
-            Arc::new(PoolStats::new(identifier, cfg.clone())),
            Arc::new(RwLock::new(None)),
+            None,
+            true,
        );

        Pool::builder()
--- a/src/plugins/intercept.rs
+++ b/src/plugins/intercept.rs
@@ -0,0 +1,120 @@
+//! The intercept plugin.
+//!
+//! It intercepts queries and returns fake results.
+
+use async_trait::async_trait;
+use bytes::{BufMut, BytesMut};
+use serde::{Deserialize, Serialize};
+use sqlparser::ast::Statement;
+
+use log::debug;
+
+use crate::{
+    config::Intercept as InterceptConfig,
+    errors::Error,
+    messages::{command_complete, data_row_nullable, row_description, DataType},
+    plugins::{Plugin, PluginOutput},
+    query_router::QueryRouter,
+};
+
+// TODO: use these structs for deserialization
+#[derive(Serialize, Deserialize)]
+pub struct Rule {
+    query: String,
+    schema: Vec<Column>,
+    result: Vec<Vec<String>>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Column {
+    name: String,
+    data_type: String,
+}
+
+/// The intercept plugin.
+pub struct Intercept<'a> {
+    pub enabled: bool,
+    pub config: &'a InterceptConfig,
+}
+
+#[async_trait]
+impl<'a> Plugin for Intercept<'a> {
+    async fn run(
+        &mut self,
+        query_router: &QueryRouter,
+        ast: &Vec<Statement>,
+    ) -> Result<PluginOutput, Error> {
+        if !self.enabled || ast.is_empty() {
+            return Ok(PluginOutput::Allow);
+        }
+
+        let mut config = self.config.clone();
+        config.substitute(
+            &query_router.pool_settings().db,
+            &query_router.pool_settings().user.username,
+        );
+
+        let mut result = BytesMut::new();
+
+        for q in ast {
+            // Normalization
+            let q = q.to_string().to_ascii_lowercase();
+
+            for (_, target) in config.queries.iter() {
+                if target.query.as_str() == q {
+                    debug!("Intercepting query: {}", q);
+
+                    let rd = target
+                        .schema
+                        .iter()
+                        .map(|row| {
+                            let name = &row[0];
+                            let data_type = &row[1];
+                            (
+                                name.as_str(),
+                                match data_type.as_str() {
+                                    "text" => DataType::Text,
+                                    "anyarray" => DataType::AnyArray,
+                                    "oid" => DataType::Oid,
+                                    "bool" => DataType::Bool,
+                                    "int4" => DataType::Int4,
+                                    _ => DataType::Any,
+                                },
+                            )
+                        })
+                        .collect::<Vec<(&str, DataType)>>();
+
+                    result.put(row_description(&rd));
+
+                    target.result.iter().for_each(|row| {
+                        let row = row
+                            .iter()
+                            .map(|s| {
+                                let s = s.as_str().to_string();
+
+                                if s == "" {
+                                    None
+                                } else {
+                                    Some(s)
+                                }
+                            })
+                            .collect::<Vec<Option<String>>>();
+                        result.put(data_row_nullable(&row));
+                    });
+
+                    result.put(command_complete("SELECT"));
+                }
+            }
+        }
+
+        if !result.is_empty() {
+            result.put_u8(b'Z');
+            result.put_i32(5);
+            result.put_u8(b'I');
+
+            return Ok(PluginOutput::Intercept(result));
+        } else {
+            Ok(PluginOutput::Allow)
+        }
+    }
+}
--- a/src/plugins/mod.rs
+++ b/src/plugins/mod.rs
@@ -0,0 +1,44 @@
+//! The plugin ecosystem.
+//!
+//! Currently plugins only grant access or deny access to the database for a particual query.
+//! Example use cases:
+//!   - block known bad queries
+//!   - block access to system catalogs
+//!   - block dangerous modifications like `DROP TABLE`
+//!   - etc
+//!
+
+pub mod intercept;
+pub mod prewarmer;
+pub mod query_logger;
+pub mod table_access;
+
+use crate::{errors::Error, query_router::QueryRouter};
+use async_trait::async_trait;
+use bytes::BytesMut;
+use sqlparser::ast::Statement;
+
+pub use intercept::Intercept;
+pub use query_logger::QueryLogger;
+pub use table_access::TableAccess;
+
+#[derive(Clone, Debug, PartialEq)]
+pub enum PluginOutput {
+    Allow,
+    Deny(String),
+    Overwrite(Vec<Statement>),
+    Intercept(BytesMut),
+}
+
+#[async_trait]
+pub trait Plugin {
+    // Run before the query is sent to the server.
+    async fn run(
+        &mut self,
+        query_router: &QueryRouter,
+        ast: &Vec<Statement>,
+    ) -> Result<PluginOutput, Error>;
+
+    // TODO: run after the result is returned
+    // async fn callback(&mut self, query_router: &QueryRouter);
+}
--- a/src/plugins/prewarmer.rs
+++ b/src/plugins/prewarmer.rs
@@ -0,0 +1,28 @@
+//! Prewarm new connections before giving them to the client.
+use crate::{errors::Error, server::Server};
+use log::info;
+
+pub struct Prewarmer<'a> {
+    pub enabled: bool,
+    pub server: &'a mut Server,
+    pub queries: &'a Vec<String>,
+}
+
+impl<'a> Prewarmer<'a> {
+    pub async fn run(&mut self) -> Result<(), Error> {
+        if !self.enabled {
+            return Ok(());
+        }
+
+        for query in self.queries {
+            info!(
+                "{} Prewarning with query: `{}`",
+                self.server.address(),
+                query
+            );
+            self.server.query(&query).await?;
+        }
+
+        Ok(())
+    }
+}
--- a/src/plugins/query_logger.rs
+++ b/src/plugins/query_logger.rs
@@ -0,0 +1,38 @@
+//! Log all queries to stdout (or somewhere else, why not).
+
+use crate::{
+    errors::Error,
+    plugins::{Plugin, PluginOutput},
+    query_router::QueryRouter,
+};
+use async_trait::async_trait;
+use log::info;
+use sqlparser::ast::Statement;
+
+pub struct QueryLogger<'a> {
+    pub enabled: bool,
+    pub user: &'a str,
+    pub db: &'a str,
+}
+
+#[async_trait]
+impl<'a> Plugin for QueryLogger<'a> {
+    async fn run(
+        &mut self,
+        _query_router: &QueryRouter,
+        ast: &Vec<Statement>,
+    ) -> Result<PluginOutput, Error> {
+        if !self.enabled {
+            return Ok(PluginOutput::Allow);
+        }
+
+        let query = ast
+            .iter()
+            .map(|q| q.to_string())
+            .collect::<Vec<String>>()
+            .join("; ");
+        info!("[pool: {}][user: {}] {}", self.user, self.db, query);
+
+        Ok(PluginOutput::Allow)
+    }
+}
--- a/src/plugins/table_access.rs
+++ b/src/plugins/table_access.rs
@@ -0,0 +1,59 @@
+//! This query router plugin will check if the user can access a particular
+//! table as part of their query. If they can't, the query will not be routed.
+
+use async_trait::async_trait;
+use sqlparser::ast::{visit_relations, Statement};
+
+use crate::{
+    errors::Error,
+    plugins::{Plugin, PluginOutput},
+    query_router::QueryRouter,
+};
+
+use log::debug;
+
+use core::ops::ControlFlow;
+
+pub struct TableAccess<'a> {
+    pub enabled: bool,
+    pub tables: &'a Vec<String>,
+}
+
+#[async_trait]
+impl<'a> Plugin for TableAccess<'a> {
+    async fn run(
+        &mut self,
+        _query_router: &QueryRouter,
+        ast: &Vec<Statement>,
+    ) -> Result<PluginOutput, Error> {
+        if !self.enabled {
+            return Ok(PluginOutput::Allow);
+        }
+
+        let mut found = None;
+
+        visit_relations(ast, |relation| {
+            let relation = relation.to_string();
+            let parts = relation.split(".").collect::<Vec<&str>>();
+            let table_name = parts.last().unwrap();
+
+            if self.tables.contains(&table_name.to_string()) {
+                found = Some(table_name.to_string());
+                ControlFlow::<()>::Break(())
+            } else {
+                ControlFlow::<()>::Continue(())
+            }
+        });
+
+        if let Some(found) = found {
+            debug!("Blocking access to table \"{}\"", found);
+
+            Ok(PluginOutput::Deny(format!(
+                "permission for table \"{}\" denied",
+                found
+            )))
+        } else {
+            Ok(PluginOutput::Allow)
+        }
+    }
+}
--- a/src/pool.rs
+++ b/src/pool.rs
@@ -1,6 +1,6 @@
 use arc_swap::ArcSwap;
 use async_trait::async_trait;
-use bb8::{ManageConnection, Pool, PooledConnection};
+use bb8::{ManageConnection, Pool, PooledConnection, QueueStrategy};
 use bytes::{BufMut, BytesMut};
 use chrono::naive::NaiveDateTime;
 use log::{debug, error, info, warn};
@@ -10,6 +10,7 @@ use rand::seq::SliceRandom;
 use rand::thread_rng;
 use regex::Regex;
 use std::collections::HashMap;
+use std::fmt::{Display, Formatter};
 use std::sync::{
    atomic::{AtomicBool, Ordering},
    Arc,
@@ -17,13 +18,16 @@ use std::sync::{
 use std::time::Instant;
 use tokio::sync::Notify;

-use crate::config::{get_config, Address, General, LoadBalancingMode, PoolMode, Role, User};
+use crate::config::{
+    get_config, Address, General, LoadBalancingMode, Plugins, PoolMode, Role, User,
+};
 use crate::errors::Error;

 use crate::auth_passthrough::AuthPassthrough;
+use crate::plugins::prewarmer;
 use crate::server::Server;
 use crate::sharding::ShardingFunction;
-use crate::stats::{AddressStats, ClientStats, PoolStats, ServerStats};
+use crate::stats::{AddressStats, ClientStats, ServerStats};

 pub type ProcessId = i32;
 pub type SecretKey = i32;
@@ -61,6 +65,8 @@ pub struct PoolIdentifier {
    pub user: String,
 }

+static POOL_REAPER_RATE: u64 = 30_000; // 30 seconds by default
+
 impl PoolIdentifier {
    /// Create a new user/pool identifier.
    pub fn new(db: &str, user: &str) -> PoolIdentifier {
@@ -71,6 +77,12 @@ impl PoolIdentifier {
    }
 }

+impl Display for PoolIdentifier {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}@{}", self.user, self.db)
+    }
+}
+
 impl From<&Address> for PoolIdentifier {
    fn from(address: &Address) -> PoolIdentifier {
        PoolIdentifier::new(&address.database, &address.username)
@@ -91,6 +103,7 @@ pub struct PoolSettings {

    // Connecting user.
    pub user: User,
+    pub db: String,

    // Default server role to connect to.
    pub default_role: Option<Role>,
@@ -129,6 +142,9 @@ pub struct PoolSettings {
    pub auth_query: Option<String>,
    pub auth_query_user: Option<String>,
    pub auth_query_password: Option<String>,
+
+    /// Plugins
+    pub plugins: Option<Plugins>,
 }

 impl Default for PoolSettings {
@@ -138,6 +154,7 @@ impl Default for PoolSettings {
            load_balancing_mode: LoadBalancingMode::Random,
            shards: 1,
            user: User::default(),
+            db: String::default(),
            default_role: None,
            query_parser_enabled: false,
            primary_reads_enabled: true,
@@ -152,6 +169,7 @@ impl Default for PoolSettings {
            auth_query: None,
            auth_query_user: None,
            auth_query_password: None,
+            plugins: None,
        }
    }
 }
@@ -191,8 +209,6 @@ pub struct ConnectionPool {
    paused: Arc<AtomicBool>,
    paused_waiter: Arc<Notify>,

-    pub stats: Arc<PoolStats>,
-
    /// AuthInfo
    pub auth_hash: Arc<RwLock<Option<String>>>,
 }
@@ -242,10 +258,6 @@ impl ConnectionPool {
                    .clone()
                    .into_keys()
                    .collect::<Vec<String>>();
-                let pool_stats = Arc::new(PoolStats::new(identifier, pool_config.clone()));
-
-                // Allow the pool to be seen in statistics
-                pool_stats.register(pool_stats.clone());

                // Sort by shard number to ensure consistency.
                shard_ids.sort_by_key(|k| k.parse::<i64>().unwrap());
@@ -311,21 +323,34 @@ impl ConnectionPool {

                        if let Some(apt) = &auth_passthrough {
                            match apt.fetch_hash(&address).await {
-				Ok(ok) => {
-				    if let Some(ref pool_auth_hash_value) = *(pool_auth_hash.read()) {
-					if ok != *pool_auth_hash_value {
-					    warn!("Hash is not the same across shards of the same pool, client auth will \
-						   be done using last obtained hash. Server: {}:{}, Database: {}", server.host, server.port, shard.database);
-					}
-				    }
-				    debug!("Hash obtained for {:?}", address);
-				    {
-					let mut pool_auth_hash = pool_auth_hash.write();
-					*pool_auth_hash = Some(ok.clone());
-				    }
-				},
-				Err(err) => warn!("Could not obtain password hashes using auth_query config, ignoring. Error: {:?}", err),
-			    }
+                                Ok(ok) => {
+                                    if let Some(ref pool_auth_hash_value) = *(pool_auth_hash.read())
+                                    {
+                                        if ok != *pool_auth_hash_value {
+                                            warn!(
+                                                "Hash is not the same across shards \
+                                                of the same pool, client auth will \
+                                                be done using last obtained hash. \
+                                                Server: {}:{}, Database: {}",
+                                                server.host, server.port, shard.database,
+                                            );
+                                        }
+                                    }
+
+                                    debug!("Hash obtained for {:?}", address);
+
+                                    {
+                                        let mut pool_auth_hash = pool_auth_hash.write();
+                                        *pool_auth_hash = Some(ok.clone());
+                                    }
+                                }
+                                Err(err) => warn!(
+                                    "Could not obtain password hashes \
+                                        using auth_query config, ignoring. \
+                                        Error: {:?}",
+                                    err,
+                                ),
+                            }
                        }

                        let manager = ServerPool::new(
@@ -333,8 +358,12 @@ impl ConnectionPool {
                            user.clone(),
                            &shard.database,
                            client_server_map.clone(),
-                            pool_stats.clone(),
                            pool_auth_hash.clone(),
+                            match pool_config.plugins {
+                                Some(ref plugins) => Some(plugins.clone()),
+                                None => config.plugins.clone(),
+                            },
+                            pool_config.cleanup_server_connections,
                        );

                        let connect_timeout = match pool_config.connect_timeout {
@@ -347,14 +376,44 @@ impl ConnectionPool {
                            None => config.general.idle_timeout,
                        };

+                        let server_lifetime = match user.server_lifetime {
+                            Some(server_lifetime) => server_lifetime,
+                            None => match pool_config.server_lifetime {
+                                Some(server_lifetime) => server_lifetime,
+                                None => config.general.server_lifetime,
+                            },
+                        };
+
+                        let reaper_rate = *vec![idle_timeout, server_lifetime, POOL_REAPER_RATE]
+                            .iter()
+                            .min()
+                            .unwrap();
+
+                        let queue_strategy = match config.general.server_round_robin {
+                            true => QueueStrategy::Fifo,
+                            false => QueueStrategy::Lifo,
+                        };
+
+                        debug!(
+                            "[pool: {}][user: {}] Pool reaper rate: {}ms",
+                            pool_name, user.username, reaper_rate
+                        );
+
                        let pool = Pool::builder()
                            .max_size(user.pool_size)
+                            .min_idle(user.min_pool_size)
                            .connection_timeout(std::time::Duration::from_millis(connect_timeout))
                            .idle_timeout(Some(std::time::Duration::from_millis(idle_timeout)))
-                            .test_on_check_out(false)
-                            .build(manager)
-                            .await
-                            .unwrap();
+                            .max_lifetime(Some(std::time::Duration::from_millis(server_lifetime)))
+                            .reaper_rate(std::time::Duration::from_millis(reaper_rate))
+                            .queue_strategy(queue_strategy)
+                            .test_on_check_out(false);
+
+                        let pool = if config.general.validate_config {
+                            pool.build(manager).await?
+                        } else {
+                            pool.build_unchecked(manager)
+                        };

                        pools.push(pool);
                        servers.push(address);
@@ -375,7 +434,6 @@ impl ConnectionPool {

                let pool = ConnectionPool {
                    databases: shards,
-                    stats: pool_stats,
                    addresses,
                    banlist: Arc::new(RwLock::new(banlist)),
                    config_hash: new_pool_hash_value,
@@ -390,6 +448,7 @@ impl ConnectionPool {
                        // shards: pool_config.shards.clone(),
                        shards: shard_ids.len(),
                        user: user.clone(),
+                        db: pool_name.clone(),
                        default_role: match pool_config.default_role.as_str() {
                            "any" => None,
                            "replica" => Some(Role::Replica),
@@ -415,6 +474,10 @@ impl ConnectionPool {
                        auth_query: pool_config.auth_query.clone(),
                        auth_query_user: pool_config.auth_query_user.clone(),
                        auth_query_password: pool_config.auth_query_password.clone(),
+                        plugins: match pool_config.plugins {
+                            Some(ref plugins) => Some(plugins.clone()),
+                            None => config.plugins.clone(),
+                        },
                    },
                    validated: Arc::new(AtomicBool::new(false)),
                    paused: Arc::new(AtomicBool::new(false)),
@@ -424,10 +487,12 @@ impl ConnectionPool {
                // Connect to the servers to make sure pool configuration is valid
                // before setting it globally.
                // Do this async and somewhere else, we don't have to wait here.
-                let mut validate_pool = pool.clone();
-                tokio::task::spawn(async move {
-                    let _ = validate_pool.validate().await;
-                });
+                if config.general.validate_config {
+                    let mut validate_pool = pool.clone();
+                    tokio::task::spawn(async move {
+                        let _ = validate_pool.validate().await;
+                    });
+                }

                // There is one pool per database/user pair.
                new_pools.insert(PoolIdentifier::new(pool_name, &user.username), pool);
@@ -549,6 +614,10 @@ impl ConnectionPool {
            });
        }

+        // Indicate we're waiting on a server connection from a pool.
+        let now = Instant::now();
+        client_stats.waiting();
+
        while !candidates.is_empty() {
            // Get the next candidate
            let address = match candidates.pop() {
@@ -567,10 +636,6 @@ impl ConnectionPool {
                }
            }

-            // Indicate we're waiting on a server connection from a pool.
-            let now = Instant::now();
-            client_stats.waiting();
-
            // Check if we can connect
            let mut conn = match self.databases[address.shard][address.address_index]
                .get()
@@ -578,7 +643,10 @@ impl ConnectionPool {
            {
                Ok(conn) => conn,
                Err(err) => {
-                    error!("Banning instance {:?}, error: {:?}", address, err);
+                    error!(
+                        "Connection checkout error for instance {:?}, error: {:?}",
+                        address, err
+                    );
                    self.ban(address, BanReason::FailedCheckout, Some(client_stats));
                    address.stats.error();
                    client_stats.idle();
@@ -605,7 +673,7 @@ impl ConnectionPool {
                    .stats()
                    .checkout_time(checkout_time, client_stats.application_name());
                server.stats().active(client_stats.application_name());
-
+                client_stats.active();
                return Ok((conn, address.clone()));
            }

@@ -613,11 +681,19 @@ impl ConnectionPool {
                .run_health_check(address, server, now, client_stats)
                .await
            {
+                let checkout_time: u64 = now.elapsed().as_micros() as u64;
+                client_stats.checkout_time(checkout_time);
+                server
+                    .stats()
+                    .checkout_time(checkout_time, client_stats.application_name());
+                server.stats().active(client_stats.application_name());
+                client_stats.active();
                return Ok((conn, address.clone()));
            } else {
                continue;
            }
        }
+        client_stats.idle();
        Err(Error::AllServersDown)
    }

@@ -654,7 +730,7 @@ impl ConnectionPool {
                // Health check failed.
                Err(err) => {
                    error!(
-                        "Banning instance {:?} because of failed health check, {:?}",
+                        "Failed health check on instance {:?}, error: {:?}",
                        address, err
                    );
                }
@@ -663,7 +739,7 @@ impl ConnectionPool {
            // Health check timed out.
            Err(err) => {
                error!(
-                    "Banning instance {:?} because of health check timeout, {:?}",
+                    "Health check timeout on instance {:?}, error: {:?}",
                    address, err
                );
            }
@@ -685,13 +761,16 @@ impl ConnectionPool {
            return;
        }

+        error!("Banning instance {:?}, reason: {:?}", address, reason);
+
        let now = chrono::offset::Utc::now().naive_utc();
        let mut guard = self.banlist.write();
-        error!("Banning {:?}", address);
+
        if let Some(client_info) = client_info {
            client_info.ban_error();
            address.stats.error();
        }
+
        guard[address.shard].insert(address.clone(), (reason, now));
    }

@@ -848,12 +927,26 @@ impl ConnectionPool {

 /// Wrapper for the bb8 connection pool.
 pub struct ServerPool {
+    /// Server address.
    address: Address,
+
+    /// Server Postgres user.
    user: User,
+
+    /// Server database.
    database: String,
+
+    /// Client/server mapping.
    client_server_map: ClientServerMap,
-    stats: Arc<PoolStats>,
+
+    /// Server auth hash (for auth passthrough).
    auth_hash: Arc<RwLock<Option<String>>>,
+
+    /// Server plugins.
+    plugins: Option<Plugins>,
+
+    /// Should we clean up dirty connections before putting them into the pool?
+    cleanup_connections: bool,
 }

 impl ServerPool {
@@ -862,16 +955,18 @@ impl ServerPool {
        user: User,
        database: &str,
        client_server_map: ClientServerMap,
-        stats: Arc<PoolStats>,
        auth_hash: Arc<RwLock<Option<String>>>,
+        plugins: Option<Plugins>,
+        cleanup_connections: bool,
    ) -> ServerPool {
        ServerPool {
            address,
            user: user.clone(),
            database: database.to_string(),
            client_server_map,
-            stats,
            auth_hash,
+            plugins,
+            cleanup_connections,
        }
    }
 }
@@ -887,7 +982,6 @@ impl ManageConnection for ServerPool {

        let stats = Arc::new(ServerStats::new(
            self.address.clone(),
-            self.stats.clone(),
            tokio::time::Instant::now(),
        ));

@@ -901,10 +995,23 @@ impl ManageConnection for ServerPool {
            self.client_server_map.clone(),
            stats.clone(),
            self.auth_hash.clone(),
+            self.cleanup_connections,
        )
        .await
        {
-            Ok(conn) => {
+            Ok(mut conn) => {
+                if let Some(ref plugins) = self.plugins {
+                    if let Some(ref prewarmer) = plugins.prewarmer {
+                        let mut prewarmer = prewarmer::Prewarmer {
+                            enabled: prewarmer.enabled,
+                            server: &mut conn,
+                            queries: &prewarmer.queries,
+                        };
+
+                        prewarmer.run().await?;
+                    }
+                }
+
                stats.idle();
                Ok(conn)
            }
--- a/src/prometheus.rs
+++ b/src/prometheus.rs
@@ -1,6 +1,6 @@
 use hyper::service::{make_service_fn, service_fn};
 use hyper::{Body, Method, Request, Response, Server, StatusCode};
-use log::{error, info, warn};
+use log::{debug, error, info};
 use phf::phf_map;
 use std::collections::HashMap;
 use std::fmt;
@@ -9,8 +9,9 @@ use std::sync::atomic::Ordering;
 use std::sync::Arc;

 use crate::config::Address;
-use crate::pool::get_all_pools;
-use crate::stats::{get_pool_stats, get_server_stats, ServerStats};
+use crate::pool::{get_all_pools, PoolIdentifier};
+use crate::stats::pool::PoolStats;
+use crate::stats::{get_server_stats, ServerStats};

 struct MetricHelpType {
    help: &'static str,
@@ -233,10 +234,10 @@ impl<Value: fmt::Display> PrometheusMetric<Value> {
        Self::from_name(&format!("stats_{}", name), value, labels)
    }

-    fn from_pool(pool: &(String, String), name: &str, value: u64) -> Option<PrometheusMetric<u64>> {
+    fn from_pool(pool_id: PoolIdentifier, name: &str, value: u64) -> Option<PrometheusMetric<u64>> {
        let mut labels = HashMap::new();
-        labels.insert("pool", pool.0.clone());
-        labels.insert("user", pool.1.clone());
+        labels.insert("pool", pool_id.db);
+        labels.insert("user", pool_id.user);

        Self::from_name(&format!("pools_{}", name), value, labels)
    }
@@ -274,7 +275,7 @@ fn push_address_stats(lines: &mut Vec<String>) {
                    {
                        lines.push(prometheus_metric.to_string());
                    } else {
-                        warn!("Metric {} not implemented for {}", key, address.name());
+                        debug!("Metric {} not implemented for {}", key, address.name());
                    }
                }
            }
@@ -284,18 +285,15 @@ fn push_address_stats(lines: &mut Vec<String>) {

 // Adds relevant metrics shown in a SHOW POOLS admin command.
 fn push_pool_stats(lines: &mut Vec<String>) {
-    let pool_stats = get_pool_stats();
-    for (pool, stats) in pool_stats.iter() {
-        let stats = &**stats;
+    let pool_stats = PoolStats::construct_pool_lookup();
+    for (pool_id, stats) in pool_stats.iter() {
        for (name, value) in stats.clone() {
-            if let Some(prometheus_metric) = PrometheusMetric::<u64>::from_pool(pool, &name, value)
+            if let Some(prometheus_metric) =
+                PrometheusMetric::<u64>::from_pool(pool_id.clone(), &name, value)
            {
                lines.push(prometheus_metric.to_string());
            } else {
-                warn!(
-                    "Metric {} not implemented for ({},{})",
-                    name, pool.0, pool.1
-                );
+                debug!("Metric {} not implemented for ({})", name, *pool_id);
            }
        }
    }
@@ -320,7 +318,7 @@ fn push_database_stats(lines: &mut Vec<String>) {
                    {
                        lines.push(prometheus_metric.to_string());
                    } else {
-                        warn!("Metric {} not implemented for {}", key, address.name());
+                        debug!("Metric {} not implemented for {}", key, address.name());
                    }
                }
            }
--- a/src/query_router.rs
+++ b/src/query_router.rs
@@ -6,13 +6,16 @@ use once_cell::sync::OnceCell;
 use regex::{Regex, RegexSet};
 use sqlparser::ast::Statement::{Query, StartTransaction};
 use sqlparser::ast::{
-    BinaryOperator, Expr, Ident, JoinConstraint, JoinOperator, SetExpr, TableFactor, Value,
+    BinaryOperator, Expr, Ident, JoinConstraint, JoinOperator, SetExpr, Statement, TableFactor,
+    Value,
 };
 use sqlparser::dialect::PostgreSqlDialect;
 use sqlparser::parser::Parser;

 use crate::config::Role;
+use crate::errors::Error;
 use crate::messages::BytesMutReader;
+use crate::plugins::{Intercept, Plugin, PluginOutput, QueryLogger, TableAccess};
 use crate::pool::PoolSettings;
 use crate::sharding::Sharder;

@@ -129,6 +132,10 @@ impl QueryRouter {
        self.pool_settings = pool_settings;
    }

+    pub fn pool_settings<'a>(&'a self) -> &'a PoolSettings {
+        &self.pool_settings
+    }
+
    /// Try to parse a command and execute it.
    pub fn try_execute_command(&mut self, message_buffer: &BytesMut) -> Option<(Command, String)> {
        let mut message_cursor = Cursor::new(message_buffer);
@@ -324,10 +331,7 @@ impl QueryRouter {
        Some((command, value))
    }

-    /// Try to infer which server to connect to based on the contents of the query.
-    pub fn infer(&mut self, message: &BytesMut) -> bool {
-        debug!("Inferring role");
-
+    pub fn parse(message: &BytesMut) -> Result<Vec<Statement>, Error> {
        let mut message_cursor = Cursor::new(message);

        let code = message_cursor.get_u8() as char;
@@ -344,37 +348,39 @@ impl QueryRouter {
            // Parse (prepared statement)
            'P' => {
                // Reads statement name
-                message_cursor.read_string().unwrap();
+                let _name = message_cursor.read_string().unwrap();

                // Reads query string
                let query = message_cursor.read_string().unwrap();

                debug!("Prepared statement: '{}'", query);
+
                query
            }

-            _ => return false,
+            _ => return Err(Error::UnsupportedStatement),
        };

-        let ast = match Parser::parse_sql(&PostgreSqlDialect {}, &query) {
-            Ok(ast) => ast,
+        match Parser::parse_sql(&PostgreSqlDialect {}, &query) {
+            Ok(ast) => Ok(ast),
            Err(err) => {
-                // SELECT ... FOR UPDATE won't get parsed correctly.
                debug!("{}: {}", err, query);
-                self.active_role = Some(Role::Primary);
-                return false;
+                Err(Error::QueryRouterParserError(err.to_string()))
            }
-        };
+        }
+    }

-        debug!("AST: {:?}", ast);
+    /// Try to infer which server to connect to based on the contents of the query.
+    pub fn infer(&mut self, ast: &Vec<sqlparser::ast::Statement>) -> Result<(), Error> {
+        debug!("Inferring role");

        if ast.is_empty() {
            // That's weird, no idea, let's go to primary
            self.active_role = Some(Role::Primary);
-            return false;
+            return Err(Error::QueryRouterParserError("empty query".into()));
        }

-        for q in &ast {
+        for q in ast {
            match q {
                // All transactions go to the primary, probably a write.
                StartTransaction { .. } => {
@@ -418,7 +424,7 @@ impl QueryRouter {
            };
        }

-        true
+        Ok(())
    }

    /// Parse the shard number from the Bind message
@@ -783,6 +789,52 @@ impl QueryRouter {
        }
    }

+    /// Add your plugins here and execute them.
+    pub async fn execute_plugins(&self, ast: &Vec<Statement>) -> Result<PluginOutput, Error> {
+        let plugins = match self.pool_settings.plugins {
+            Some(ref plugins) => plugins,
+            None => return Ok(PluginOutput::Allow),
+        };
+
+        if let Some(ref query_logger) = plugins.query_logger {
+            let mut query_logger = QueryLogger {
+                enabled: query_logger.enabled,
+                user: &self.pool_settings.user.username,
+                db: &self.pool_settings.db,
+            };
+
+            let _ = query_logger.run(&self, ast).await;
+        }
+
+        if let Some(ref intercept) = plugins.intercept {
+            let mut intercept = Intercept {
+                enabled: intercept.enabled,
+                config: &intercept,
+            };
+
+            let result = intercept.run(&self, ast).await;
+
+            if let Ok(PluginOutput::Intercept(output)) = result {
+                return Ok(PluginOutput::Intercept(output));
+            }
+        }
+
+        if let Some(ref table_access) = plugins.table_access {
+            let mut table_access = TableAccess {
+                enabled: table_access.enabled,
+                tables: &table_access.tables,
+            };
+
+            let result = table_access.run(&self, ast).await;
+
+            if let Ok(PluginOutput::Deny(error)) = result {
+                return Ok(PluginOutput::Deny(error));
+            }
+        }
+
+        Ok(PluginOutput::Allow)
+    }
+
    fn set_sharding_key(&mut self, sharding_key: i64) -> Option<usize> {
        let sharder = Sharder::new(
            self.pool_settings.shards,
@@ -810,11 +862,22 @@ impl QueryRouter {
    /// Should we attempt to parse queries?
    pub fn query_parser_enabled(&self) -> bool {
        let enabled = match self.query_parser_enabled {
-            None => self.pool_settings.query_parser_enabled,
-            Some(value) => value,
-        };
+            None => {
+                debug!(
+                    "Using pool settings, query_parser_enabled: {}",
+                    self.pool_settings.query_parser_enabled
+                );
+                self.pool_settings.query_parser_enabled
+            }

-        debug!("Query parser enabled: {}", enabled);
+            Some(value) => {
+                debug!(
+                    "Using query parser override, query_parser_enabled: {}",
+                    value
+                );
+                value
+            }
+        };

        enabled
    }
@@ -862,7 +925,7 @@ mod test {

        for query in queries {
            // It's a recognized query
-            assert!(qr.infer(&query));
+            assert!(qr.infer(&QueryRouter::parse(&query).unwrap()).is_ok());
            assert_eq!(qr.role(), Some(Role::Replica));
        }
    }
@@ -881,7 +944,7 @@ mod test {

        for query in queries {
            // It's a recognized query
-            assert!(qr.infer(&query));
+            assert!(qr.infer(&QueryRouter::parse(&query).unwrap()).is_ok());
            assert_eq!(qr.role(), Some(Role::Primary));
        }
    }
@@ -893,7 +956,7 @@ mod test {
        let query = simple_query("SELECT * FROM items WHERE id = 5");
        assert!(qr.try_execute_command(&simple_query("SET PRIMARY READS TO on")) != None);

-        assert!(qr.infer(&query));
+        assert!(qr.infer(&QueryRouter::parse(&query).unwrap()).is_ok());
        assert_eq!(qr.role(), None);
    }

@@ -913,7 +976,7 @@ mod test {
        res.put(prepared_stmt);
        res.put_i16(0);

-        assert!(qr.infer(&res));
+        assert!(qr.infer(&QueryRouter::parse(&res).unwrap()).is_ok());
        assert_eq!(qr.role(), Some(Role::Replica));
    }

@@ -1077,11 +1140,11 @@ mod test {
        assert_eq!(qr.role(), None);

        let query = simple_query("INSERT INTO test_table VALUES (1)");
-        assert!(qr.infer(&query));
+        assert!(qr.infer(&QueryRouter::parse(&query).unwrap()).is_ok());
        assert_eq!(qr.role(), Some(Role::Primary));

        let query = simple_query("SELECT * FROM test_table");
-        assert!(qr.infer(&query));
+        assert!(qr.infer(&QueryRouter::parse(&query).unwrap()).is_ok());
        assert_eq!(qr.role(), Some(Role::Replica));

        assert!(qr.query_parser_enabled());
@@ -1113,6 +1176,8 @@ mod test {
            auth_query: None,
            auth_query_password: None,
            auth_query_user: None,
+            db: "test".to_string(),
+            plugins: None,
        };
        let mut qr = QueryRouter::new();
        assert_eq!(qr.active_role, None);
@@ -1142,15 +1207,24 @@ mod test {
        QueryRouter::setup();

        let mut qr = QueryRouter::new();
-        assert!(qr.infer(&simple_query("BEGIN; SELECT 1; COMMIT;")));
+        assert!(qr
+            .infer(&QueryRouter::parse(&simple_query("BEGIN; SELECT 1; COMMIT;")).unwrap())
+            .is_ok());
        assert_eq!(qr.role(), Role::Primary);

-        assert!(qr.infer(&simple_query("SELECT 1; SELECT 2;")));
+        assert!(qr
+            .infer(&QueryRouter::parse(&simple_query("SELECT 1; SELECT 2;")).unwrap())
+            .is_ok());
        assert_eq!(qr.role(), Role::Replica);

-        assert!(qr.infer(&simple_query(
-            "SELECT 123; INSERT INTO t VALUES (5); SELECT 1;"
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    "SELECT 123; INSERT INTO t VALUES (5); SELECT 1;"
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.role(), Role::Primary);
    }

@@ -1177,7 +1251,10 @@ mod test {
            auth_query: None,
            auth_query_password: None,
            auth_query_user: None,
+            db: "test".to_string(),
+            plugins: None,
        };
+
        let mut qr = QueryRouter::new();
        qr.update_pool_settings(pool_settings.clone());

@@ -1208,47 +1285,84 @@ mod test {
        qr.pool_settings.automatic_sharding_key = Some("data.id".to_string());
        qr.pool_settings.shards = 3;

-        assert!(qr.infer(&simple_query("SELECT * FROM data WHERE id = 5")));
+        assert!(qr
+            .infer(&QueryRouter::parse(&simple_query("SELECT * FROM data WHERE id = 5")).unwrap())
+            .is_ok());
        assert_eq!(qr.shard(), 2);

-        assert!(qr.infer(&simple_query(
-            "SELECT one, two, three FROM public.data WHERE id = 6"
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    "SELECT one, two, three FROM public.data WHERE id = 6"
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 0);

-        assert!(qr.infer(&simple_query(
-            "SELECT * FROM data
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    "SELECT * FROM data
            INNER JOIN t2 ON data.id = 5
            AND t2.data_id = data.id
        WHERE data.id = 5"
-        )));
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 2);

        // Shard did not move because we couldn't determine the sharding key since it could be ambiguous
        // in the query.
-        assert!(qr.infer(&simple_query(
-            "SELECT * FROM t2 INNER JOIN data ON id = 6 AND data.id = t2.data_id"
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    "SELECT * FROM t2 INNER JOIN data ON id = 6 AND data.id = t2.data_id"
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 2);

-        assert!(qr.infer(&simple_query(
-            r#"SELECT * FROM "public"."data" WHERE "id" = 6"#
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    r#"SELECT * FROM "public"."data" WHERE "id" = 6"#
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 0);

-        assert!(qr.infer(&simple_query(
-            r#"SELECT * FROM "public"."data" WHERE "data"."id" = 5"#
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    r#"SELECT * FROM "public"."data" WHERE "data"."id" = 5"#
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 2);

        // Super unique sharding key
        qr.pool_settings.automatic_sharding_key = Some("*.unique_enough_column_name".to_string());
-        assert!(qr.infer(&simple_query(
-            "SELECT * FROM table_x WHERE unique_enough_column_name = 6"
-        )));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query(
+                    "SELECT * FROM table_x WHERE unique_enough_column_name = 6"
+                ))
+                .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 0);

-        assert!(qr.infer(&simple_query("SELECT * FROM table_y WHERE another_key = 5")));
+        assert!(qr
+            .infer(
+                &QueryRouter::parse(&simple_query("SELECT * FROM table_y WHERE another_key = 5"))
+                    .unwrap()
+            )
+            .is_ok());
        assert_eq!(qr.shard(), 0);
    }

@@ -1272,11 +1386,61 @@ mod test {
        qr.pool_settings.automatic_sharding_key = Some("data.id".to_string());
        qr.pool_settings.shards = 3;

-        assert!(qr.infer(&simple_query(stmt)));
+        assert!(qr
+            .infer(&QueryRouter::parse(&simple_query(stmt)).unwrap())
+            .is_ok());
        assert_eq!(qr.placeholders.len(), 1);

        assert!(qr.infer_shard_from_bind(&bind));
        assert_eq!(qr.shard(), 2);
        assert!(qr.placeholders.is_empty());
    }
+
+    #[tokio::test]
+    async fn test_table_access_plugin() {
+        use crate::config::{Plugins, TableAccess};
+        let table_access = TableAccess {
+            enabled: true,
+            tables: vec![String::from("pg_database")],
+        };
+        let plugins = Plugins {
+            table_access: Some(table_access),
+            intercept: None,
+            query_logger: None,
+            prewarmer: None,
+        };
+
+        QueryRouter::setup();
+        let mut pool_settings = PoolSettings::default();
+        pool_settings.query_parser_enabled = true;
+        pool_settings.plugins = Some(plugins);
+
+        let mut qr = QueryRouter::new();
+        qr.update_pool_settings(pool_settings);
+
+        let query = simple_query("SELECT * FROM pg_database");
+        let ast = QueryRouter::parse(&query).unwrap();
+
+        let res = qr.execute_plugins(&ast).await;
+
+        assert_eq!(
+            res,
+            Ok(PluginOutput::Deny(
+                "permission for table \"pg_database\" denied".to_string()
+            ))
+        );
+    }
+
+    #[tokio::test]
+    async fn test_plugins_disabled_by_defaault() {
+        QueryRouter::setup();
+        let qr = QueryRouter::new();
+
+        let query = simple_query("SELECT * FROM pg_database");
+        let ast = QueryRouter::parse(&query).unwrap();
+
+        let res = qr.execute_plugins(&ast).await;
+
+        assert_eq!(res, Ok(PluginOutput::Allow));
+    }
 }
--- a/src/server.rs
+++ b/src/server.rs
@@ -5,24 +5,145 @@ use fallible_iterator::FallibleIterator;
 use log::{debug, error, info, trace, warn};
 use parking_lot::{Mutex, RwLock};
 use postgres_protocol::message;
-use std::collections::HashMap;
+use std::collections::{BTreeSet, HashMap};
 use std::io::Read;
+use std::net::IpAddr;
 use std::sync::Arc;
 use std::time::SystemTime;
-use tokio::io::{AsyncReadExt, BufReader};
-use tokio::net::{
-    tcp::{OwnedReadHalf, OwnedWriteHalf},
-    TcpStream,
-};
+use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, BufStream};
+use tokio::net::TcpStream;
+use tokio_rustls::rustls::{OwnedTrustAnchor, RootCertStore};
+use tokio_rustls::{client::TlsStream, TlsConnector};

-use crate::config::{Address, User};
+use crate::config::{get_config, Address, User};
 use crate::constants::*;
+use crate::dns_cache::{AddrSet, CACHED_RESOLVER};
 use crate::errors::{Error, ServerIdentifier};
 use crate::messages::*;
 use crate::mirrors::MirroringManager;
 use crate::pool::ClientServerMap;
 use crate::scram::ScramSha256;
 use crate::stats::ServerStats;
+use std::io::Write;
+
+use pin_project::pin_project;
+
+#[pin_project(project = SteamInnerProj)]
+pub enum StreamInner {
+    Plain {
+        #[pin]
+        stream: TcpStream,
+    },
+    Tls {
+        #[pin]
+        stream: TlsStream<TcpStream>,
+    },
+}
+
+impl AsyncWrite for StreamInner {
+    fn poll_write(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &[u8],
+    ) -> std::task::Poll<Result<usize, std::io::Error>> {
+        let this = self.project();
+        match this {
+            SteamInnerProj::Tls { stream } => stream.poll_write(cx, buf),
+            SteamInnerProj::Plain { stream } => stream.poll_write(cx, buf),
+        }
+    }
+
+    fn poll_flush(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), std::io::Error>> {
+        let this = self.project();
+        match this {
+            SteamInnerProj::Tls { stream } => stream.poll_flush(cx),
+            SteamInnerProj::Plain { stream } => stream.poll_flush(cx),
+        }
+    }
+
+    fn poll_shutdown(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Result<(), std::io::Error>> {
+        let this = self.project();
+        match this {
+            SteamInnerProj::Tls { stream } => stream.poll_shutdown(cx),
+            SteamInnerProj::Plain { stream } => stream.poll_shutdown(cx),
+        }
+    }
+}
+
+impl AsyncRead for StreamInner {
+    fn poll_read(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &mut tokio::io::ReadBuf<'_>,
+    ) -> std::task::Poll<std::io::Result<()>> {
+        let this = self.project();
+        match this {
+            SteamInnerProj::Tls { stream } => stream.poll_read(cx, buf),
+            SteamInnerProj::Plain { stream } => stream.poll_read(cx, buf),
+        }
+    }
+}
+
+impl StreamInner {
+    pub fn try_write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        match self {
+            StreamInner::Tls { stream } => {
+                let r = stream.get_mut();
+                let mut w = r.1.writer();
+                w.write(buf)
+            }
+            StreamInner::Plain { stream } => stream.try_write(buf),
+        }
+    }
+}
+
+#[derive(Copy, Clone)]
+struct CleanupState {
+    /// If server connection requires DISCARD ALL before checkin because of set statement
+    needs_cleanup_set: bool,
+
+    /// If server connection requires DISCARD ALL before checkin because of prepare statement
+    needs_cleanup_prepare: bool,
+}
+
+impl CleanupState {
+    fn new() -> Self {
+        CleanupState {
+            needs_cleanup_set: false,
+            needs_cleanup_prepare: false,
+        }
+    }
+
+    fn needs_cleanup(&self) -> bool {
+        self.needs_cleanup_set || self.needs_cleanup_prepare
+    }
+
+    fn set_true(&mut self) {
+        self.needs_cleanup_set = true;
+        self.needs_cleanup_prepare = true;
+    }
+
+    fn reset(&mut self) {
+        self.needs_cleanup_set = false;
+        self.needs_cleanup_prepare = false;
+    }
+}
+
+impl std::fmt::Display for CleanupState {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "SET: {}, PREPARE: {}",
+            self.needs_cleanup_set, self.needs_cleanup_prepare
+        )
+    }
+}

 /// Server state.
 pub struct Server {
@@ -30,11 +151,8 @@ pub struct Server {
    /// port, e.g. 5432, and role, e.g. primary or replica.
    address: Address,

-    /// Buffered read socket.
-    read: BufReader<OwnedReadHalf>,
-
-    /// Unbuffered write socket (our client code buffers).
-    write: OwnedWriteHalf,
+    /// Server TCP connection.
+    stream: BufStream<StreamInner>,

    /// Our server response buffer. We buffer data before we give it to the client.
    buffer: BytesMut,
@@ -55,8 +173,8 @@ pub struct Server {
    /// Is the server broken? We'll remote it from the pool if so.
    bad: bool,

-    /// If server connection requires a DISCARD ALL before checkin
-    needs_cleanup: bool,
+    /// If server connection requires DISCARD ALL before checkin
+    cleanup_state: CleanupState,

    /// Mapping of clients and servers used for query cancellation.
    client_server_map: ClientServerMap,
@@ -70,10 +188,19 @@ pub struct Server {
    /// Application name using the server at the moment.
    application_name: String,

-    // Last time that a successful server send or response happened
+    /// Last time that a successful server send or response happened
    last_activity: SystemTime,

    mirror_manager: Option<MirroringManager>,
+
+    /// Associated addresses used
+    addr_set: Option<AddrSet>,
+
+    /// Should clean up dirty connections?
+    cleanup_connections: bool,
+
+    /// Prepared statements
+    prepared_statements: BTreeSet<String>,
 }

 impl Server {
@@ -86,7 +213,26 @@ impl Server {
        client_server_map: ClientServerMap,
        stats: Arc<ServerStats>,
        auth_hash: Arc<RwLock<Option<String>>>,
+        cleanup_connections: bool,
    ) -> Result<Server, Error> {
+        let cached_resolver = CACHED_RESOLVER.load();
+        let mut addr_set: Option<AddrSet> = None;
+
+        // If we are caching addresses and hostname is not an IP
+        if cached_resolver.enabled() && address.host.parse::<IpAddr>().is_err() {
+            debug!("Resolving {}", &address.host);
+            addr_set = match cached_resolver.lookup_ip(&address.host).await {
+                Ok(ok) => {
+                    debug!("Obtained: {:?}", ok);
+                    Some(ok)
+                }
+                Err(err) => {
+                    warn!("Error trying to resolve {}, ({:?})", &address.host, err);
+                    None
+                }
+            }
+        };
+
        let mut stream =
            match TcpStream::connect(&format!("{}:{}", &address.host, address.port)).await {
                Ok(stream) => stream,
@@ -98,8 +244,88 @@ impl Server {
                    )));
                }
            };
+
+        // TCP timeouts.
        configure_socket(&stream);

+        let config = get_config();
+
+        let mut stream = if config.general.server_tls {
+            // Request a TLS connection
+            ssl_request(&mut stream).await?;
+
+            let response = match stream.read_u8().await {
+                Ok(response) => response as char,
+                Err(err) => {
+                    return Err(Error::SocketError(format!(
+                        "Server socket error: {:?}",
+                        err
+                    )))
+                }
+            };
+
+            match response {
+                // Server supports TLS
+                'S' => {
+                    debug!("Connecting to server using TLS");
+
+                    let mut root_store = RootCertStore::empty();
+                    root_store.add_server_trust_anchors(
+                        webpki_roots::TLS_SERVER_ROOTS.0.iter().map(|ta| {
+                            OwnedTrustAnchor::from_subject_spki_name_constraints(
+                                ta.subject,
+                                ta.spki,
+                                ta.name_constraints,
+                            )
+                        }),
+                    );
+
+                    let mut tls_config = rustls::ClientConfig::builder()
+                        .with_safe_defaults()
+                        .with_root_certificates(root_store)
+                        .with_no_client_auth();
+
+                    // Equivalent to sslmode=prefer which is fine most places.
+                    // If you want verify-full, change `verify_server_certificate` to true.
+                    if !config.general.verify_server_certificate {
+                        let mut dangerous = tls_config.dangerous();
+                        dangerous.set_certificate_verifier(Arc::new(
+                            crate::tls::NoCertificateVerification {},
+                        ));
+                    }
+
+                    let connector = TlsConnector::from(Arc::new(tls_config));
+                    let stream = match connector
+                        .connect(address.host.as_str().try_into().unwrap(), stream)
+                        .await
+                    {
+                        Ok(stream) => stream,
+                        Err(err) => {
+                            return Err(Error::SocketError(format!("Server TLS error: {:?}", err)))
+                        }
+                    };
+
+                    StreamInner::Tls { stream }
+                }
+
+                // Server does not support TLS
+                'N' => StreamInner::Plain { stream },
+
+                // Something else?
+                m => {
+                    return Err(Error::SocketError(format!(
+                        "Unknown message: {}",
+                        m as char
+                    )));
+                }
+            }
+        } else {
+            StreamInner::Plain { stream }
+        };
+
+        // let (read, write) = split(stream);
+        // let (mut read, mut write) = (ReadInner::Plain { stream: read }, WriteInner::Plain { stream: write });
+
        trace!("Sending StartupMessage");

        // StartupMessage
@@ -245,7 +471,7 @@ impl Server {

                            let sasl_type = String::from_utf8_lossy(&sasl_auth[..sasl_len - 2]);

-                            if sasl_type == SCRAM_SHA_256 {
+                            if sasl_type.contains(SCRAM_SHA_256) {
                                debug!("Using {}", SCRAM_SHA_256);

                                // Generate client message.
@@ -268,7 +494,7 @@ impl Server {
                                res.put_i32(sasl_response.len() as i32);
                                res.put(sasl_response);

-                                write_all(&mut stream, res).await?;
+                                write_all_flush(&mut stream, &res).await?;
                            } else {
                                error!("Unsupported SCRAM version: {}", sasl_type);
                                return Err(Error::ServerError);
@@ -299,7 +525,7 @@ impl Server {
                            res.put_i32(4 + sasl_response.len() as i32);
                            res.put(sasl_response);

-                            write_all(&mut stream, res).await?;
+                            write_all_flush(&mut stream, &res).await?;
                        }

                        SASL_FINAL => {
@@ -443,12 +669,9 @@ impl Server {
                        }
                    };

-                    let (read, write) = stream.into_split();
-
                    let mut server = Server {
                        address: address.clone(),
-                        read: BufReader::new(read),
-                        write,
+                        stream: BufStream::new(stream),
                        buffer: BytesMut::with_capacity(8196),
                        server_info,
                        process_id,
@@ -456,8 +679,9 @@ impl Server {
                        in_transaction: false,
                        data_available: false,
                        bad: false,
-                        needs_cleanup: false,
+                        cleanup_state: CleanupState::new(),
                        client_server_map,
+                        addr_set,
                        connected_at: chrono::offset::Utc::now().naive_utc(),
                        stats,
                        application_name: String::new(),
@@ -470,6 +694,8 @@ impl Server {
                                address.mirrors.clone(),
                            )),
                        },
+                        cleanup_connections,
+                        prepared_statements: BTreeSet::new(),
                    };

                    server.set_name("pgcat").await?;
@@ -515,7 +741,7 @@ impl Server {
        bytes.put_i32(process_id);
        bytes.put_i32(secret_key);

-        write_all(&mut stream, bytes).await
+        write_all_flush(&mut stream, &bytes).await
    }

    /// Send messages to the server from the client.
@@ -523,14 +749,17 @@ impl Server {
        self.mirror_send(messages);
        self.stats().data_sent(messages.len());

-        match write_all_half(&mut self.write, messages).await {
+        match write_all_flush(&mut self.stream, &messages).await {
            Ok(_) => {
                // Successfully sent to server
                self.last_activity = SystemTime::now();
                Ok(())
            }
            Err(err) => {
-                error!("Terminating server because of: {:?}", err);
+                error!(
+                    "Terminating server {:?} because of: {:?}",
+                    self.address, err
+                );
                self.bad = true;
                Err(err)
            }
@@ -542,10 +771,13 @@ impl Server {
    /// in order to receive all data the server has to offer.
    pub async fn recv(&mut self) -> Result<BytesMut, Error> {
        loop {
-            let mut message = match read_message(&mut self.read).await {
+            let mut message = match read_message(&mut self.stream).await {
                Ok(message) => message,
                Err(err) => {
-                    error!("Terminating server because of: {:?}", err);
+                    error!(
+                        "Terminating server {:?} because of: {:?}",
+                        self.address, err
+                    );
                    self.bad = true;
                    return Err(err);
                }
@@ -612,12 +844,12 @@ impl Server {
                                    // This will reduce amount of discard statements sent
                                    if !self.in_transaction {
                                        debug!("Server connection marked for clean up");
-                                        self.needs_cleanup = true;
+                                        self.cleanup_state.needs_cleanup_set = true;
                                    }
                                }
                                "PREPARE\0" => {
                                    debug!("Server connection marked for clean up");
-                                    self.needs_cleanup = true;
+                                    self.cleanup_state.needs_cleanup_prepare = true;
                                }
                                _ => (),
                            }
@@ -682,6 +914,43 @@ impl Server {
        Ok(bytes)
    }

+    pub fn will_prepare(&mut self, name: &str) {
+        debug!("Will prepare `{}`", name);
+
+        self.prepared_statements.insert(name.to_string());
+    }
+
+    pub fn should_prepare(&self, name: &str) -> bool {
+        let should_prepare = !self.prepared_statements.contains(name);
+
+        debug!("Should prepare `{}`: {}", name, should_prepare);
+
+        if should_prepare {
+            self.stats.prepared_cache_miss();
+        } else {
+            self.stats.prepared_cache_hit();
+        }
+
+        should_prepare
+    }
+
+    pub async fn prepare(&mut self, parse: &Parse) -> Result<(), Error> {
+        debug!("Preparing `{}`", parse.name);
+
+        let bytes: BytesMut = parse.try_into()?;
+        self.send(&bytes).await?;
+        self.send(&flush()).await?;
+
+        // Read and discard ParseComplete (B)
+        let _ = read_message(&mut self.stream).await?;
+
+        self.prepared_statements.insert(parse.name.to_string());
+
+        debug!("Prepared `{}`", parse.name);
+
+        Ok(())
+    }
+
    /// If the server is still inside a transaction.
    /// If the client disconnects while the server is in a transaction, we will clean it up.
    pub fn in_transaction(&self) -> bool {
@@ -698,7 +967,23 @@ impl Server {
    /// Server & client are out of sync, we must discard this connection.
    /// This happens with clients that misbehave.
    pub fn is_bad(&self) -> bool {
-        self.bad
+        if self.bad {
+            return self.bad;
+        };
+        let cached_resolver = CACHED_RESOLVER.load();
+        if cached_resolver.enabled() {
+            if let Some(addr_set) = &self.addr_set {
+                if cached_resolver.has_changed(self.address.host.as_str(), addr_set) {
+                    warn!(
+                        "DNS changed for {}, it was {:?}. Dropping server connection.",
+                        self.address.host.as_str(),
+                        addr_set
+                    );
+                    return true;
+                }
+            }
+        }
+        false
    }

    /// Get server startup information to forward it to the client.
@@ -731,6 +1016,8 @@ impl Server {
    /// It will use the simple query protocol.
    /// Result will not be returned, so this is useful for things like `SET` or `ROLLBACK`.
    pub async fn query(&mut self, query: &str) -> Result<(), Error> {
+        debug!("Running `{}` on server {:?}", query, self.address);
+
        let query = simple_query(query);

        self.send(&query).await?;
@@ -763,10 +1050,11 @@ impl Server {
        // to avoid leaking state between clients. For performance reasons we only
        // send `DISCARD ALL` if we think the session is altered instead of just sending
        // it before each checkin.
-        if self.needs_cleanup {
-            warn!("Server returned with session state altered, discarding state");
+        if self.cleanup_state.needs_cleanup() && self.cleanup_connections {
+            warn!("Server returned with session state altered, discarding state ({}) for application {}", self.cleanup_state, self.application_name);
            self.query("DISCARD ALL").await?;
-            self.needs_cleanup = false;
+            self.query("RESET ROLE").await?;
+            self.cleanup_state.reset();
        }

        Ok(())
@@ -778,12 +1066,12 @@ impl Server {
            self.application_name = name.to_string();
            // We don't want `SET application_name` to mark the server connection
            // as needing cleanup
-            let needs_cleanup_before = self.needs_cleanup;
+            let needs_cleanup_before = self.cleanup_state;

            let result = Ok(self
                .query(&format!("SET application_name = '{}'", name))
                .await?);
-            self.needs_cleanup = needs_cleanup_before;
+            self.cleanup_state = needs_cleanup_before;
            result
        } else {
            Ok(())
@@ -808,7 +1096,7 @@ impl Server {

    // Marks a connection as needing DISCARD ALL at checkin
    pub fn mark_dirty(&mut self) {
-        self.needs_cleanup = true;
+        self.cleanup_state.set_true();
    }

    pub fn mirror_send(&mut self, bytes: &BytesMut) {
@@ -842,6 +1130,7 @@ impl Server {
            client_server_map,
            Arc::new(ServerStats::default()),
            Arc::new(RwLock::new(None)),
+            true,
        )
        .await?;
        debug!("Connected!, sending query.");
@@ -935,23 +1224,27 @@ impl Drop for Server {
        // Update statistics
        self.stats.disconnect();

-        let mut bytes = BytesMut::with_capacity(4);
+        let mut bytes = BytesMut::with_capacity(5);
        bytes.put_u8(b'X');
        bytes.put_i32(4);

-        match self.write.try_write(&bytes) {
-            Ok(_) => (),
-            Err(_) => debug!("Dirty shutdown"),
+        match self.stream.get_mut().try_write(&bytes) {
+            Ok(5) => (),
+            _ => debug!("Dirty shutdown"),
        };

-        // Should not matter.
-        self.bad = true;
-
        let now = chrono::offset::Utc::now().naive_utc();
        let duration = now - self.connected_at;

+        let message = if self.bad {
+            "Server connection terminated"
+        } else {
+            "Server connection closed"
+        };
+
        info!(
-            "Server connection closed {:?}, session duration: {}",
+            "{} {:?}, session duration: {}",
+            message,
            self.address,
            crate::format_duration(&duration)
        );
--- a/src/stats.rs
+++ b/src/stats.rs
@@ -1,4 +1,3 @@
-use crate::pool::PoolIdentifier;
 /// Statistics and reporting.
 use arc_swap::ArcSwap;

@@ -16,13 +15,11 @@ pub mod pool;
 pub mod server;
 pub use address::AddressStats;
 pub use client::{ClientState, ClientStats};
-pub use pool::PoolStats;
 pub use server::{ServerState, ServerStats};

 /// Convenience types for various stats
 type ClientStatesLookup = HashMap<i32, Arc<ClientStats>>;
 type ServerStatesLookup = HashMap<i32, Arc<ServerStats>>;
-type PoolStatsLookup = HashMap<(String, String), Arc<PoolStats>>;

 /// Stats for individual client connections
 /// Used in SHOW CLIENTS.
@@ -34,11 +31,6 @@ static CLIENT_STATS: Lazy<Arc<RwLock<ClientStatesLookup>>> =
 static SERVER_STATS: Lazy<Arc<RwLock<ServerStatesLookup>>> =
    Lazy::new(|| Arc::new(RwLock::new(ServerStatesLookup::default())));

-/// Aggregate stats for each pool (a pool is identified by database name and username)
-/// Used in SHOW POOLS.
-static POOL_STATS: Lazy<Arc<RwLock<PoolStatsLookup>>> =
-    Lazy::new(|| Arc::new(RwLock::new(PoolStatsLookup::default())));
-
 /// The statistics reporter. An instance is given to each possible source of statistics,
 /// e.g. client stats, server stats, connection pool stats.
 pub static REPORTER: Lazy<ArcSwap<Reporter>> =
@@ -80,13 +72,6 @@ impl Reporter {
    fn server_disconnecting(&self, server_id: i32) {
        SERVER_STATS.write().remove(&server_id);
    }
-
-    /// Register a pool with the stats system.
-    fn pool_register(&self, identifier: PoolIdentifier, stats: Arc<PoolStats>) {
-        POOL_STATS
-            .write()
-            .insert((identifier.db, identifier.user), stats);
-    }
 }

 /// The statistics collector which used for calculating averages
@@ -107,8 +92,20 @@ impl Collector {
            loop {
                interval.tick().await;

-                for stats in SERVER_STATS.read().values() {
-                    stats.address_stats().update_averages();
+                // Hold read lock for duration of update to retain all server stats
+                let server_stats = SERVER_STATS.read();
+
+                for stats in server_stats.values() {
+                    if !stats.check_address_stat_average_is_updated_status() {
+                        stats.address_stats().update_averages();
+                        stats.address_stats().reset_current_counts();
+                        stats.set_address_stat_average_is_updated_status(true);
+                    }
+                }
+
+                // Reset to false for next update
+                for stats in server_stats.values() {
+                    stats.set_address_stat_average_is_updated_status(false);
                }
            }
        });
@@ -127,12 +124,6 @@ pub fn get_server_stats() -> ServerStatesLookup {
    SERVER_STATS.read().clone()
 }

-/// Get a snapshot of pool statistics.
-/// by the `Collector`.
-pub fn get_pool_stats() -> PoolStatsLookup {
-    POOL_STATS.read().clone()
-}
-
 /// Get the statistics reporter used to update stats across the pools/clients.
 pub fn get_reporter() -> Reporter {
    (*(*REPORTER.load())).clone()
--- a/src/stats/address.rs
+++ b/src/stats/address.rs
@@ -1,26 +1,29 @@
-use log::warn;
 use std::sync::atomic::*;
 use std::sync::Arc;

+#[derive(Debug, Clone, Default)]
+struct AddressStatFields {
+    xact_count: Arc<AtomicU64>,
+    query_count: Arc<AtomicU64>,
+    bytes_received: Arc<AtomicU64>,
+    bytes_sent: Arc<AtomicU64>,
+    xact_time: Arc<AtomicU64>,
+    query_time: Arc<AtomicU64>,
+    wait_time: Arc<AtomicU64>,
+    errors: Arc<AtomicU64>,
+}
+
 /// Internal address stats
 #[derive(Debug, Clone, Default)]
 pub struct AddressStats {
-    pub total_xact_count: Arc<AtomicU64>,
-    pub total_query_count: Arc<AtomicU64>,
-    pub total_received: Arc<AtomicU64>,
-    pub total_sent: Arc<AtomicU64>,
-    pub total_xact_time: Arc<AtomicU64>,
-    pub total_query_time: Arc<AtomicU64>,
-    pub total_wait_time: Arc<AtomicU64>,
-    pub total_errors: Arc<AtomicU64>,
-    pub avg_query_count: Arc<AtomicU64>,
-    pub avg_query_time: Arc<AtomicU64>,
-    pub avg_recv: Arc<AtomicU64>,
-    pub avg_sent: Arc<AtomicU64>,
-    pub avg_errors: Arc<AtomicU64>,
-    pub avg_xact_time: Arc<AtomicU64>,
-    pub avg_xact_count: Arc<AtomicU64>,
-    pub avg_wait_time: Arc<AtomicU64>,
+    total: AddressStatFields,
+
+    current: AddressStatFields,
+
+    averages: AddressStatFields,
+
+    // Determines if the averages have been updated since the last time they were reported
+    pub averages_updated: Arc<AtomicBool>,
 }

 impl IntoIterator for AddressStats {
@@ -31,67 +34,67 @@ impl IntoIterator for AddressStats {
        vec![
            (
                "total_xact_count".to_string(),
-                self.total_xact_count.load(Ordering::Relaxed),
+                self.total.xact_count.load(Ordering::Relaxed),
            ),
            (
                "total_query_count".to_string(),
-                self.total_query_count.load(Ordering::Relaxed),
+                self.total.query_count.load(Ordering::Relaxed),
            ),
            (
                "total_received".to_string(),
-                self.total_received.load(Ordering::Relaxed),
+                self.total.bytes_received.load(Ordering::Relaxed),
            ),
            (
                "total_sent".to_string(),
-                self.total_sent.load(Ordering::Relaxed),
+                self.total.bytes_sent.load(Ordering::Relaxed),
            ),
            (
                "total_xact_time".to_string(),
-                self.total_xact_time.load(Ordering::Relaxed),
+                self.total.xact_time.load(Ordering::Relaxed),
            ),
            (
                "total_query_time".to_string(),
-                self.total_query_time.load(Ordering::Relaxed),
+                self.total.query_time.load(Ordering::Relaxed),
            ),
            (
                "total_wait_time".to_string(),
-                self.total_wait_time.load(Ordering::Relaxed),
+                self.total.wait_time.load(Ordering::Relaxed),
            ),
            (
                "total_errors".to_string(),
-                self.total_errors.load(Ordering::Relaxed),
+                self.total.errors.load(Ordering::Relaxed),
            ),
            (
                "avg_xact_count".to_string(),
-                self.avg_xact_count.load(Ordering::Relaxed),
+                self.averages.xact_count.load(Ordering::Relaxed),
            ),
            (
                "avg_query_count".to_string(),
-                self.avg_query_count.load(Ordering::Relaxed),
+                self.averages.query_count.load(Ordering::Relaxed),
            ),
            (
                "avg_recv".to_string(),
-                self.avg_recv.load(Ordering::Relaxed),
+                self.averages.bytes_received.load(Ordering::Relaxed),
            ),
            (
                "avg_sent".to_string(),
-                self.avg_sent.load(Ordering::Relaxed),
+                self.averages.bytes_sent.load(Ordering::Relaxed),
            ),
            (
                "avg_errors".to_string(),
-                self.avg_errors.load(Ordering::Relaxed),
+                self.averages.errors.load(Ordering::Relaxed),
            ),
            (
                "avg_xact_time".to_string(),
-                self.avg_xact_time.load(Ordering::Relaxed),
+                self.averages.xact_time.load(Ordering::Relaxed),
            ),
            (
                "avg_query_time".to_string(),
-                self.avg_query_time.load(Ordering::Relaxed),
+                self.averages.query_time.load(Ordering::Relaxed),
            ),
            (
                "avg_wait_time".to_string(),
-                self.avg_wait_time.load(Ordering::Relaxed),
+                self.averages.wait_time.load(Ordering::Relaxed),
            ),
        ]
        .into_iter()
@@ -99,22 +102,120 @@ impl IntoIterator for AddressStats {
 }

 impl AddressStats {
+    pub fn xact_count_add(&self) {
+        self.total.xact_count.fetch_add(1, Ordering::Relaxed);
+        self.current.xact_count.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn query_count_add(&self) {
+        self.total.query_count.fetch_add(1, Ordering::Relaxed);
+        self.current.query_count.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn bytes_received_add(&self, bytes: u64) {
+        self.total
+            .bytes_received
+            .fetch_add(bytes, Ordering::Relaxed);
+        self.current
+            .bytes_received
+            .fetch_add(bytes, Ordering::Relaxed);
+    }
+
+    pub fn bytes_sent_add(&self, bytes: u64) {
+        self.total.bytes_sent.fetch_add(bytes, Ordering::Relaxed);
+        self.current.bytes_sent.fetch_add(bytes, Ordering::Relaxed);
+    }
+
+    pub fn xact_time_add(&self, time: u64) {
+        self.total.xact_time.fetch_add(time, Ordering::Relaxed);
+        self.current.xact_time.fetch_add(time, Ordering::Relaxed);
+    }
+
+    pub fn query_time_add(&self, time: u64) {
+        self.total.query_time.fetch_add(time, Ordering::Relaxed);
+        self.current.query_time.fetch_add(time, Ordering::Relaxed);
+    }
+
+    pub fn wait_time_add(&self, time: u64) {
+        self.total.wait_time.fetch_add(time, Ordering::Relaxed);
+        self.current.wait_time.fetch_add(time, Ordering::Relaxed);
+    }
+
    pub fn error(&self) {
-        self.total_errors.fetch_add(1, Ordering::Relaxed);
+        self.total.errors.fetch_add(1, Ordering::Relaxed);
+        self.current.errors.fetch_add(1, Ordering::Relaxed);
    }

    pub fn update_averages(&self) {
-        let (totals, averages) = self.fields_iterators();
-        for data in totals.iter().zip(averages.iter()) {
-            let (total, average) = data;
-            if let Err(err) = average.fetch_update(Ordering::Relaxed, Ordering::Relaxed, |avg| {
-                let total = total.load(Ordering::Relaxed);
-                let avg = (total - avg) / (crate::stats::STAT_PERIOD / 1_000); // Avg / second
-                Some(avg)
-            }) {
-                warn!("Could not update averages for addresses stats, {:?}", err);
-            }
+        let stat_period_per_second = crate::stats::STAT_PERIOD / 1_000;
+
+        // xact_count
+        let current_xact_count = self.current.xact_count.load(Ordering::Relaxed);
+        let current_xact_time = self.current.xact_time.load(Ordering::Relaxed);
+        self.averages.xact_count.store(
+            current_xact_count / stat_period_per_second,
+            Ordering::Relaxed,
+        );
+        if current_xact_count == 0 {
+            self.averages.xact_time.store(0, Ordering::Relaxed);
+        } else {
+            self.averages
+                .xact_time
+                .store(current_xact_time / current_xact_count, Ordering::Relaxed);
        }
+
+        // query_count
+        let current_query_count = self.current.query_count.load(Ordering::Relaxed);
+        let current_query_time = self.current.query_time.load(Ordering::Relaxed);
+        self.averages.query_count.store(
+            current_query_count / stat_period_per_second,
+            Ordering::Relaxed,
+        );
+        if current_query_count == 0 {
+            self.averages.query_time.store(0, Ordering::Relaxed);
+        } else {
+            self.averages
+                .query_time
+                .store(current_query_time / current_query_count, Ordering::Relaxed);
+        }
+
+        // bytes_received
+        let current_bytes_received = self.current.bytes_received.load(Ordering::Relaxed);
+        self.averages.bytes_received.store(
+            current_bytes_received / stat_period_per_second,
+            Ordering::Relaxed,
+        );
+
+        // bytes_sent
+        let current_bytes_sent = self.current.bytes_sent.load(Ordering::Relaxed);
+        self.averages.bytes_sent.store(
+            current_bytes_sent / stat_period_per_second,
+            Ordering::Relaxed,
+        );
+
+        // wait_time
+        let current_wait_time = self.current.wait_time.load(Ordering::Relaxed);
+        self.averages.wait_time.store(
+            current_wait_time / stat_period_per_second,
+            Ordering::Relaxed,
+        );
+
+        // errors
+        let current_errors = self.current.errors.load(Ordering::Relaxed);
+        self.averages
+            .errors
+            .store(current_errors / stat_period_per_second, Ordering::Relaxed);
+    }
+
+    pub fn reset_current_counts(&self) {
+        self.current.xact_count.store(0, Ordering::Relaxed);
+        self.current.xact_time.store(0, Ordering::Relaxed);
+        self.current.query_count.store(0, Ordering::Relaxed);
+        self.current.query_time.store(0, Ordering::Relaxed);
+        self.current.bytes_received.store(0, Ordering::Relaxed);
+        self.current.bytes_sent.store(0, Ordering::Relaxed);
+        self.current.wait_time.store(0, Ordering::Relaxed);
+        self.current.errors.store(0, Ordering::Relaxed);
    }

    pub fn populate_row(&self, row: &mut Vec<String>) {
@@ -122,28 +223,4 @@ impl AddressStats {
            row.push(value.to_string());
        }
    }
-
-    fn fields_iterators(&self) -> (Vec<Arc<AtomicU64>>, Vec<Arc<AtomicU64>>) {
-        let mut totals: Vec<Arc<AtomicU64>> = Vec::new();
-        let mut averages: Vec<Arc<AtomicU64>> = Vec::new();
-
-        totals.push(self.total_xact_count.clone());
-        averages.push(self.avg_xact_count.clone());
-        totals.push(self.total_query_count.clone());
-        averages.push(self.avg_query_count.clone());
-        totals.push(self.total_received.clone());
-        averages.push(self.avg_recv.clone());
-        totals.push(self.total_sent.clone());
-        averages.push(self.avg_sent.clone());
-        totals.push(self.total_xact_time.clone());
-        averages.push(self.avg_xact_time.clone());
-        totals.push(self.total_query_time.clone());
-        averages.push(self.avg_query_time.clone());
-        totals.push(self.total_wait_time.clone());
-        averages.push(self.avg_wait_time.clone());
-        totals.push(self.total_errors.clone());
-        averages.push(self.avg_errors.clone());
-
-        (totals, averages)
-    }
 }
--- a/src/stats/client.rs
+++ b/src/stats/client.rs
@@ -1,4 +1,3 @@
-use super::PoolStats;
 use super::{get_reporter, Reporter};
 use atomic_enum::atomic_enum;
 use std::sync::atomic::*;
@@ -34,12 +33,14 @@ pub struct ClientStats {
    pool_name: String,
    connect_time: Instant,

-    pool_stats: Arc<PoolStats>,
    reporter: Reporter,

    /// Total time spent waiting for a connection from pool, measures in microseconds
    pub total_wait_time: Arc<AtomicU64>,

+    /// Maximum time spent waiting for a connection from pool, measures in microseconds
+    pub max_wait_time: Arc<AtomicU64>,
+
    /// Current state of the client
    pub state: Arc<AtomicClientState>,

@@ -61,8 +62,8 @@ impl Default for ClientStats {
            application_name: String::new(),
            username: String::new(),
            pool_name: String::new(),
-            pool_stats: Arc::new(PoolStats::default()),
            total_wait_time: Arc::new(AtomicU64::new(0)),
+            max_wait_time: Arc::new(AtomicU64::new(0)),
            state: Arc::new(AtomicClientState::new(ClientState::Idle)),
            transaction_count: Arc::new(AtomicU64::new(0)),
            query_count: Arc::new(AtomicU64::new(0)),
@@ -79,11 +80,9 @@ impl ClientStats {
        username: &str,
        pool_name: &str,
        connect_time: Instant,
-        pool_stats: Arc<PoolStats>,
    ) -> Self {
        Self {
            client_id,
-            pool_stats,
            connect_time,
            application_name: application_name.to_string(),
            username: username.to_string(),
@@ -96,8 +95,6 @@ impl ClientStats {
    /// update metrics on the corresponding pool.
    pub fn disconnect(&self) {
        self.reporter.client_disconnecting(self.client_id);
-        self.pool_stats
-            .client_disconnect(self.state.load(Ordering::Relaxed))
    }

    /// Register a client with the stats system. The stats system uses client_id
@@ -105,27 +102,20 @@ impl ClientStats {
    pub fn register(&self, stats: Arc<ClientStats>) {
        self.reporter.client_register(self.client_id, stats);
        self.state.store(ClientState::Idle, Ordering::Relaxed);
-        self.pool_stats.cl_idle.fetch_add(1, Ordering::Relaxed);
    }

    /// Reports a client is done querying the server and is no longer assigned a server connection
    pub fn idle(&self) {
-        self.pool_stats
-            .client_idle(self.state.load(Ordering::Relaxed));
        self.state.store(ClientState::Idle, Ordering::Relaxed);
    }

    /// Reports a client is waiting for a connection
    pub fn waiting(&self) {
-        self.pool_stats
-            .client_waiting(self.state.load(Ordering::Relaxed));
        self.state.store(ClientState::Waiting, Ordering::Relaxed);
    }

    /// Reports a client is done waiting for a connection and is about to query the server.
    pub fn active(&self) {
-        self.pool_stats
-            .client_active(self.state.load(Ordering::Relaxed));
        self.state.store(ClientState::Active, Ordering::Relaxed);
    }

@@ -144,6 +134,8 @@ impl ClientStats {
    pub fn checkout_time(&self, microseconds: u64) {
        self.total_wait_time
            .fetch_add(microseconds, Ordering::Relaxed);
+        self.max_wait_time
+            .fetch_max(microseconds, Ordering::Relaxed);
    }

    /// Report a query executed by a client against a server
--- a/src/stats/pool.rs
+++ b/src/stats/pool.rs
@@ -1,36 +1,131 @@
-use crate::config::Pool;
-use crate::config::PoolMode;
-use crate::pool::PoolIdentifier;
-use std::sync::atomic::*;
-use std::sync::Arc;
+use log::debug;

-use super::get_reporter;
-use super::Reporter;
 use super::{ClientState, ServerState};
+use crate::{config::PoolMode, messages::DataType, pool::PoolIdentifier};
+use std::collections::HashMap;
+use std::sync::atomic::*;

-#[derive(Debug, Clone, Default)]
+use crate::pool::get_all_pools;
+
+#[derive(Debug, Clone)]
 /// A struct that holds information about a Pool .
 pub struct PoolStats {
-    // Pool identifier, cannot be changed after creating the instance
-    identifier: PoolIdentifier,
+    pub identifier: PoolIdentifier,
+    pub mode: PoolMode,
+    pub cl_idle: u64,
+    pub cl_active: u64,
+    pub cl_waiting: u64,
+    pub cl_cancel_req: u64,
+    pub sv_active: u64,
+    pub sv_idle: u64,
+    pub sv_used: u64,
+    pub sv_tested: u64,
+    pub sv_login: u64,
+    pub maxwait: u64,
+}
+impl PoolStats {
+    pub fn new(identifier: PoolIdentifier, mode: PoolMode) -> Self {
+        PoolStats {
+            identifier,
+            mode,
+            cl_idle: 0,
+            cl_active: 0,
+            cl_waiting: 0,
+            cl_cancel_req: 0,
+            sv_active: 0,
+            sv_idle: 0,
+            sv_used: 0,
+            sv_tested: 0,
+            sv_login: 0,
+            maxwait: 0,
+        }
+    }

-    // Pool Config, cannot be changed after creating the instance
-    config: Pool,
+    pub fn construct_pool_lookup() -> HashMap<PoolIdentifier, PoolStats> {
+        let mut map: HashMap<PoolIdentifier, PoolStats> = HashMap::new();
+        let client_map = super::get_client_stats();
+        let server_map = super::get_server_stats();

-    // A reference to the global reporter.
-    reporter: Reporter,
+        for (identifier, pool) in get_all_pools() {
+            map.insert(
+                identifier.clone(),
+                PoolStats::new(identifier, pool.settings.pool_mode),
+            );
+        }

-    /// Counters (atomics)
-    pub cl_idle: Arc<AtomicU64>,
-    pub cl_active: Arc<AtomicU64>,
-    pub cl_waiting: Arc<AtomicU64>,
-    pub cl_cancel_req: Arc<AtomicU64>,
-    pub sv_active: Arc<AtomicU64>,
-    pub sv_idle: Arc<AtomicU64>,
-    pub sv_used: Arc<AtomicU64>,
-    pub sv_tested: Arc<AtomicU64>,
-    pub sv_login: Arc<AtomicU64>,
-    pub maxwait: Arc<AtomicU64>,
+        for client in client_map.values() {
+            match map.get_mut(&PoolIdentifier {
+                db: client.pool_name(),
+                user: client.username(),
+            }) {
+                Some(pool_stats) => {
+                    match client.state.load(Ordering::Relaxed) {
+                        ClientState::Active => pool_stats.cl_active += 1,
+                        ClientState::Idle => pool_stats.cl_idle += 1,
+                        ClientState::Waiting => pool_stats.cl_waiting += 1,
+                    }
+                    let max_wait = client.max_wait_time.load(Ordering::Relaxed);
+                    pool_stats.maxwait = std::cmp::max(pool_stats.maxwait, max_wait);
+                }
+                None => debug!("Client from an obselete pool"),
+            }
+        }
+
+        for server in server_map.values() {
+            match map.get_mut(&PoolIdentifier {
+                db: server.pool_name(),
+                user: server.username(),
+            }) {
+                Some(pool_stats) => match server.state.load(Ordering::Relaxed) {
+                    ServerState::Active => pool_stats.sv_active += 1,
+                    ServerState::Idle => pool_stats.sv_idle += 1,
+                    ServerState::Login => pool_stats.sv_login += 1,
+                    ServerState::Tested => pool_stats.sv_tested += 1,
+                },
+                None => debug!("Server from an obselete pool"),
+            }
+        }
+
+        return map;
+    }
+
+    pub fn generate_header() -> Vec<(&'static str, DataType)> {
+        return vec![
+            ("database", DataType::Text),
+            ("user", DataType::Text),
+            ("pool_mode", DataType::Text),
+            ("cl_idle", DataType::Numeric),
+            ("cl_active", DataType::Numeric),
+            ("cl_waiting", DataType::Numeric),
+            ("cl_cancel_req", DataType::Numeric),
+            ("sv_active", DataType::Numeric),
+            ("sv_idle", DataType::Numeric),
+            ("sv_used", DataType::Numeric),
+            ("sv_tested", DataType::Numeric),
+            ("sv_login", DataType::Numeric),
+            ("maxwait", DataType::Numeric),
+            ("maxwait_us", DataType::Numeric),
+        ];
+    }
+
+    pub fn generate_row(&self) -> Vec<String> {
+        return vec![
+            self.identifier.db.clone(),
+            self.identifier.user.clone(),
+            self.mode.to_string(),
+            self.cl_idle.to_string(),
+            self.cl_active.to_string(),
+            self.cl_waiting.to_string(),
+            self.cl_cancel_req.to_string(),
+            self.sv_active.to_string(),
+            self.sv_idle.to_string(),
+            self.sv_used.to_string(),
+            self.sv_tested.to_string(),
+            self.sv_login.to_string(),
+            (self.maxwait / 1_000_000).to_string(),
+            (self.maxwait % 1_000_000).to_string(),
+        ];
+    }
 }

 impl IntoIterator for PoolStats {
@@ -39,236 +134,18 @@ impl IntoIterator for PoolStats {

    fn into_iter(self) -> Self::IntoIter {
        vec![
-            ("cl_idle".to_string(), self.cl_idle.load(Ordering::Relaxed)),
-            (
-                "cl_active".to_string(),
-                self.cl_active.load(Ordering::Relaxed),
-            ),
-            (
-                "cl_waiting".to_string(),
-                self.cl_waiting.load(Ordering::Relaxed),
-            ),
-            (
-                "cl_cancel_req".to_string(),
-                self.cl_cancel_req.load(Ordering::Relaxed),
-            ),
-            (
-                "sv_active".to_string(),
-                self.sv_active.load(Ordering::Relaxed),
-            ),
-            ("sv_idle".to_string(), self.sv_idle.load(Ordering::Relaxed)),
-            ("sv_used".to_string(), self.sv_used.load(Ordering::Relaxed)),
-            (
-                "sv_tested".to_string(),
-                self.sv_tested.load(Ordering::Relaxed),
-            ),
-            (
-                "sv_login".to_string(),
-                self.sv_login.load(Ordering::Relaxed),
-            ),
-            (
-                "maxwait".to_string(),
-                self.maxwait.load(Ordering::Relaxed) / 1_000_000,
-            ),
-            (
-                "maxwait_us".to_string(),
-                self.maxwait.load(Ordering::Relaxed) % 1_000_000,
-            ),
+            ("cl_idle".to_string(), self.cl_idle),
+            ("cl_active".to_string(), self.cl_active),
+            ("cl_waiting".to_string(), self.cl_waiting),
+            ("cl_cancel_req".to_string(), self.cl_cancel_req),
+            ("sv_active".to_string(), self.sv_active),
+            ("sv_idle".to_string(), self.sv_idle),
+            ("sv_used".to_string(), self.sv_used),
+            ("sv_tested".to_string(), self.sv_tested),
+            ("sv_login".to_string(), self.sv_login),
+            ("maxwait".to_string(), self.maxwait / 1_000_000),
+            ("maxwait_us".to_string(), self.maxwait % 1_000_000),
        ]
        .into_iter()
    }
 }
-
-impl PoolStats {
-    pub fn new(identifier: PoolIdentifier, config: Pool) -> Self {
-        Self {
-            identifier,
-            config,
-            reporter: get_reporter(),
-            ..Default::default()
-        }
-    }
-
-    // Getters
-    pub fn register(&self, stats: Arc<PoolStats>) {
-        self.reporter.pool_register(self.identifier.clone(), stats);
-    }
-
-    pub fn database(&self) -> String {
-        self.identifier.db.clone()
-    }
-
-    pub fn user(&self) -> String {
-        self.identifier.user.clone()
-    }
-
-    pub fn pool_mode(&self) -> PoolMode {
-        self.config.pool_mode
-    }
-
-    /// Populates an array of strings with counters (used by admin in show pools)
-    pub fn populate_row(&self, row: &mut Vec<String>) {
-        for (_key, value) in self.clone() {
-            row.push(value.to_string());
-        }
-    }
-
-    /// Deletes the maxwait counter, this is done everytime we obtain metrics
-    pub fn clear_maxwait(&self) {
-        self.maxwait.store(0, Ordering::Relaxed);
-    }
-
-    /// Notified when a server of the pool enters login state.
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the server that notifies.
-    pub fn server_login(&self, from: ServerState) {
-        self.sv_login.fetch_add(1, Ordering::Relaxed);
-        if from != ServerState::Login {
-            self.decrease_from_server_state(from);
-        }
-    }
-
-    /// Notified when a server of the pool become 'active'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the server that notifies.
-    pub fn server_active(&self, from: ServerState) {
-        self.sv_active.fetch_add(1, Ordering::Relaxed);
-        if from != ServerState::Active {
-            self.decrease_from_server_state(from);
-        }
-    }
-
-    /// Notified when a server of the pool become 'tested'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the server that notifies.
-    pub fn server_tested(&self, from: ServerState) {
-        self.sv_tested.fetch_add(1, Ordering::Relaxed);
-        if from != ServerState::Tested {
-            self.decrease_from_server_state(from);
-        }
-    }
-
-    /// Notified when a server of the pool become 'idle'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the server that notifies.
-    pub fn server_idle(&self, from: ServerState) {
-        self.sv_idle.fetch_add(1, Ordering::Relaxed);
-        if from != ServerState::Idle {
-            self.decrease_from_server_state(from);
-        }
-    }
-
-    /// Notified when a client of the pool become 'waiting'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the client that notifies.
-    pub fn client_waiting(&self, from: ClientState) {
-        if from != ClientState::Waiting {
-            self.cl_waiting.fetch_add(1, Ordering::Relaxed);
-            self.decrease_from_client_state(from);
-        }
-    }
-
-    /// Notified when a client of the pool become 'active'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the client that notifies.
-    pub fn client_active(&self, from: ClientState) {
-        if from != ClientState::Active {
-            self.cl_active.fetch_add(1, Ordering::Relaxed);
-            self.decrease_from_client_state(from);
-        }
-    }
-
-    /// Notified when a client of the pool become 'idle'
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the client that notifies.
-    pub fn client_idle(&self, from: ClientState) {
-        if from != ClientState::Idle {
-            self.cl_idle.fetch_add(1, Ordering::Relaxed);
-            self.decrease_from_client_state(from);
-        }
-    }
-
-    /// Notified when a client disconnects.
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the client that notifies.
-    pub fn client_disconnect(&self, from: ClientState) {
-        let counter = match from {
-            ClientState::Idle => &self.cl_idle,
-            ClientState::Waiting => &self.cl_waiting,
-            ClientState::Active => &self.cl_active,
-        };
-
-        Self::decrease_counter(counter.clone());
-    }
-
-    /// Notified when a server disconnects.
-    ///
-    /// Arguments:
-    ///
-    /// `from`: The state of the client that notifies.
-    pub fn server_disconnect(&self, from: ServerState) {
-        let counter = match from {
-            ServerState::Active => &self.sv_active,
-            ServerState::Idle => &self.sv_idle,
-            ServerState::Login => &self.sv_login,
-            ServerState::Tested => &self.sv_tested,
-        };
-        Self::decrease_counter(counter.clone());
-    }
-
-    // helpers for counter decrease
-    fn decrease_from_server_state(&self, from: ServerState) {
-        let counter = match from {
-            ServerState::Tested => &self.sv_tested,
-            ServerState::Active => &self.sv_active,
-            ServerState::Idle => &self.sv_idle,
-            ServerState::Login => &self.sv_login,
-        };
-        Self::decrease_counter(counter.clone());
-    }
-
-    fn decrease_from_client_state(&self, from: ClientState) {
-        let counter = match from {
-            ClientState::Active => &self.cl_active,
-            ClientState::Idle => &self.cl_idle,
-            ClientState::Waiting => &self.cl_waiting,
-        };
-        Self::decrease_counter(counter.clone());
-    }
-
-    fn decrease_counter(value: Arc<AtomicU64>) {
-        if value.load(Ordering::Relaxed) > 0 {
-            value.fetch_sub(1, Ordering::Relaxed);
-        }
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn test_decrease() {
-        let stat: PoolStats = PoolStats::default();
-        stat.server_login(ServerState::Login);
-        stat.server_idle(ServerState::Login);
-        assert_eq!(stat.sv_login.load(Ordering::Relaxed), 0);
-        assert_eq!(stat.sv_idle.load(Ordering::Relaxed), 1);
-    }
-}
--- a/src/stats/server.rs
+++ b/src/stats/server.rs
@@ -1,5 +1,4 @@
 use super::AddressStats;
-use super::PoolStats;
 use super::{get_reporter, Reporter};
 use crate::config::Address;
 use atomic_enum::atomic_enum;
@@ -38,7 +37,6 @@ pub struct ServerStats {
    address: Address,
    connect_time: Instant,

-    pool_stats: Arc<PoolStats>,
    reporter: Reporter,

    /// Data
@@ -49,6 +47,8 @@ pub struct ServerStats {
    pub transaction_count: Arc<AtomicU64>,
    pub query_count: Arc<AtomicU64>,
    pub error_count: Arc<AtomicU64>,
+    pub prepared_hit_count: Arc<AtomicU64>,
+    pub prepared_miss_count: Arc<AtomicU64>,
 }

 impl Default for ServerStats {
@@ -57,7 +57,6 @@ impl Default for ServerStats {
            server_id: 0,
            application_name: Arc::new(RwLock::new(String::new())),
            address: Address::default(),
-            pool_stats: Arc::new(PoolStats::default()),
            connect_time: Instant::now(),
            state: Arc::new(AtomicServerState::new(ServerState::Login)),
            bytes_sent: Arc::new(AtomicU64::new(0)),
@@ -66,15 +65,16 @@ impl Default for ServerStats {
            query_count: Arc::new(AtomicU64::new(0)),
            error_count: Arc::new(AtomicU64::new(0)),
            reporter: get_reporter(),
+            prepared_hit_count: Arc::new(AtomicU64::new(0)),
+            prepared_miss_count: Arc::new(AtomicU64::new(0)),
        }
    }
 }

 impl ServerStats {
-    pub fn new(address: Address, pool_stats: Arc<PoolStats>, connect_time: Instant) -> Self {
+    pub fn new(address: Address, connect_time: Instant) -> Self {
        Self {
            address,
-            pool_stats,
            connect_time,
            server_id: rand::random::<i32>(),
            ..Default::default()
@@ -96,9 +96,6 @@ impl ServerStats {
    /// Reports a server connection is no longer assigned to a client
    /// and is available for the next client to pick it up
    pub fn idle(&self) {
-        self.pool_stats
-            .server_idle(self.state.load(Ordering::Relaxed));
-
        self.state.store(ServerState::Idle, Ordering::Relaxed);
    }

@@ -106,22 +103,16 @@ impl ServerStats {
    /// Also updates metrics on the pool regarding server usage.
    pub fn disconnect(&self) {
        self.reporter.server_disconnecting(self.server_id);
-        self.pool_stats
-            .server_disconnect(self.state.load(Ordering::Relaxed))
    }

    /// Reports a server connection is being tested before being given to a client.
    pub fn tested(&self) {
        self.set_undefined_application();
-        self.pool_stats
-            .server_tested(self.state.load(Ordering::Relaxed));
        self.state.store(ServerState::Tested, Ordering::Relaxed);
    }

    /// Reports a server connection is attempting to login.
    pub fn login(&self) {
-        self.pool_stats
-            .server_login(self.state.load(Ordering::Relaxed));
        self.state.store(ServerState::Login, Ordering::Relaxed);
        self.set_undefined_application();
    }
@@ -129,8 +120,6 @@ impl ServerStats {
    /// Reports a server connection has been assigned to a client that
    /// is about to query the server
    pub fn active(&self, application_name: String) {
-        self.pool_stats
-            .server_active(self.state.load(Ordering::Relaxed));
        self.state.store(ServerState::Active, Ordering::Relaxed);
        self.set_application(application_name);
    }
@@ -139,13 +128,24 @@ impl ServerStats {
        self.address.stats.clone()
    }

+    pub fn check_address_stat_average_is_updated_status(&self) -> bool {
+        self.address.stats.averages_updated.load(Ordering::Relaxed)
+    }
+
+    pub fn set_address_stat_average_is_updated_status(&self, is_checked: bool) {
+        self.address
+            .stats
+            .averages_updated
+            .store(is_checked, Ordering::Relaxed);
+    }
+
    // Helper methods for show_servers
    pub fn pool_name(&self) -> String {
-        self.pool_stats.database()
+        self.address.pool_name.clone()
    }

    pub fn username(&self) -> String {
-        self.pool_stats.user()
+        self.address.username.clone()
    }

    pub fn address_name(&self) -> String {
@@ -166,27 +166,17 @@ impl ServerStats {
    }

    pub fn checkout_time(&self, microseconds: u64, application_name: String) {
-        // Update server stats and address aggergation stats
+        // Update server stats and address aggregation stats
        self.set_application(application_name);
-        self.address
-            .stats
-            .total_wait_time
-            .fetch_add(microseconds, Ordering::Relaxed);
-        self.pool_stats
-            .maxwait
-            .fetch_max(microseconds, Ordering::Relaxed);
+        self.address.stats.wait_time_add(microseconds);
    }

    /// Report a query executed by a client against a server
    pub fn query(&self, milliseconds: u64, application_name: &str) {
        self.set_application(application_name.to_string());
-        let address_stats = self.address_stats();
-        address_stats
-            .total_query_count
-            .fetch_add(1, Ordering::Relaxed);
-        address_stats
-            .total_query_time
-            .fetch_add(milliseconds, Ordering::Relaxed);
+        self.address.stats.query_count_add();
+        self.address.stats.query_time_add(milliseconds);
+        self.query_count.fetch_add(1, Ordering::Relaxed);
    }

    /// Report a transaction executed by a client a server
@@ -197,29 +187,30 @@ impl ServerStats {
        self.set_application(application_name.to_string());

        self.transaction_count.fetch_add(1, Ordering::Relaxed);
-        self.address
-            .stats
-            .total_xact_count
-            .fetch_add(1, Ordering::Relaxed);
+        self.address.stats.xact_count_add();
    }

    /// Report data sent to a server
    pub fn data_sent(&self, amount_bytes: usize) {
        self.bytes_sent
            .fetch_add(amount_bytes as u64, Ordering::Relaxed);
-        self.address
-            .stats
-            .total_sent
-            .fetch_add(amount_bytes as u64, Ordering::Relaxed);
+        self.address.stats.bytes_sent_add(amount_bytes as u64);
    }

    /// Report data received from a server
    pub fn data_received(&self, amount_bytes: usize) {
        self.bytes_received
            .fetch_add(amount_bytes as u64, Ordering::Relaxed);
-        self.address
-            .stats
-            .total_received
-            .fetch_add(amount_bytes as u64, Ordering::Relaxed);
+        self.address.stats.bytes_received_add(amount_bytes as u64);
+    }
+
+    /// Report a prepared statement that already exists on the server.
+    pub fn prepared_cache_hit(&self) {
+        self.prepared_hit_count.fetch_add(1, Ordering::Relaxed);
+    }
+
+    /// Report a prepared statement that does not exist on the server yet.
+    pub fn prepared_cache_miss(&self) {
+        self.prepared_miss_count.fetch_add(1, Ordering::Relaxed);
    }
 }
--- a/src/tls.rs
+++ b/src/tls.rs
@@ -4,7 +4,12 @@ use rustls_pemfile::{certs, read_one, Item};
 use std::iter;
 use std::path::Path;
 use std::sync::Arc;
-use tokio_rustls::rustls::{self, Certificate, PrivateKey};
+use std::time::SystemTime;
+use tokio_rustls::rustls::{
+    self,
+    client::{ServerCertVerified, ServerCertVerifier},
+    Certificate, PrivateKey, ServerName,
+};
 use tokio_rustls::TlsAcceptor;

 use crate::config::get_config;
@@ -64,3 +69,19 @@ impl Tls {
        })
    }
 }
+
+pub struct NoCertificateVerification;
+
+impl ServerCertVerifier for NoCertificateVerification {
+    fn verify_server_cert(
+        &self,
+        _end_entity: &Certificate,
+        _intermediates: &[Certificate],
+        _server_name: &ServerName,
+        _scts: &mut dyn Iterator<Item = &[u8]>,
+        _ocsp_response: &[u8],
+        _now: SystemTime,
+    ) -> Result<ServerCertVerified, rustls::Error> {
+        Ok(ServerCertVerified::assertion())
+    }
+}
--- a/tests/python/tests.py
+++ b/tests/python/tests.py
@@ -63,6 +63,7 @@ def cleanup_conn(conn: psycopg2.extensions.connection, cur: psycopg2.extensions.


 def test_normal_db_access():
+    pgcat_start()
    conn, cur = connect_db(autocommit=False)
    cur.execute("SELECT 1")
    res = cur.fetchall()
--- a/tests/ruby/admin_spec.rb
+++ b/tests/ruby/admin_spec.rb
@@ -11,323 +11,6 @@ describe "Admin" do
    processes.pgcat.shutdown
  end

-  describe "SHOW STATS" do
-    context "clients connect and make one query" do
-      it "updates *_query_time and *_wait_time" do
-        connection = PG::connect("#{pgcat_conn_str}?application_name=one_query")
-        connection.async_exec("SELECT pg_sleep(0.25)")
-        connection.async_exec("SELECT pg_sleep(0.25)")
-        connection.async_exec("SELECT pg_sleep(0.25)")
-        connection.close
-
-        # wait for averages to be calculated, we shouldn't do this too often
-        sleep(15.5)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW STATS")[0]
-        admin_conn.close
-        expect(results["total_query_time"].to_i).to be_within(200).of(750)
-        expect(results["avg_query_time"].to_i).to_not eq(0)
-
-        expect(results["total_wait_time"].to_i).to_not eq(0)
-        expect(results["avg_wait_time"].to_i).to_not eq(0)
-      end
-    end
-  end
-
-  describe "SHOW POOLS" do
-    context "bad credentials" do
-      it "does not change any stats" do
-        bad_password_url = URI(pgcat_conn_str)
-        bad_password_url.password = "wrong"
-        expect { PG::connect("#{bad_password_url.to_s}?application_name=bad_password") }.to raise_error(PG::ConnectionBad)
-
-        sleep(1)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-
-        expect(results["sv_idle"]).to eq("1")
-      end
-    end
-
-    context "bad database name" do
-      it "does not change any stats" do
-        bad_db_url = URI(pgcat_conn_str)
-        bad_db_url.path = "/wrong_db"
-        expect { PG::connect("#{bad_db_url.to_s}?application_name=bad_db") }.to raise_error(PG::ConnectionBad)
-
-        sleep(1)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-
-        expect(results["sv_idle"]).to eq("1")
-      end
-    end
-
-    context "client connects but issues no queries" do
-      it "only affects cl_idle stats" do
-        connections = Array.new(20) { PG::connect(pgcat_conn_str) }
-        sleep(1)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["cl_idle"]).to eq("20")
-        expect(results["sv_idle"]).to eq("1")
-
-        connections.map(&:close)
-        sleep(1.1)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_active cl_idle cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["sv_idle"]).to eq("1")
-      end
-    end
-
-    context "clients connect and make one query" do
-      it "only affects cl_idle, sv_idle stats" do
-        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          Thread.new { c.async_exec("SELECT pg_sleep(2.5)") }
-        end
-
-        sleep(1.1)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_waiting cl_cancel_req sv_idle sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["cl_active"]).to eq("5")
-        expect(results["sv_active"]).to eq("5")
-
-        sleep(3)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["cl_idle"]).to eq("5")
-        expect(results["sv_idle"]).to eq("5")
-
-        connections.map(&:close)
-        sleep(1)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["sv_idle"]).to eq("5")
-      end
-    end
-
-    context "client connects and opens a transaction and closes connection uncleanly" do
-      it "produces correct statistics" do
-        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          Thread.new do
-            c.async_exec("BEGIN")
-            c.async_exec("SELECT pg_sleep(0.01)")
-            c.close
-          end
-        end
-
-        sleep(1.1)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["sv_idle"]).to eq("5")
-      end
-    end
-
-    context "client fail to checkout connection from the pool" do
-      it "counts clients as idle" do
-        new_configs = processes.pgcat.current_config
-        new_configs["general"]["connect_timeout"] = 500
-        new_configs["general"]["ban_time"] = 1
-        new_configs["general"]["shutdown_timeout"] = 1
-        new_configs["pools"]["sharded_db"]["users"]["0"]["pool_size"] = 1
-        processes.pgcat.update_config(new_configs)
-        processes.pgcat.reload_config
-
-        threads = []
-        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          threads << Thread.new { c.async_exec("SELECT pg_sleep(1)") rescue PG::SystemError }
-        end
-
-        sleep(2)
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["cl_idle"]).to eq("5")
-        expect(results["sv_idle"]).to eq("1")
-
-        threads.map(&:join)
-        connections.map(&:close)
-      end
-    end
-
-    context "clients connects and disconnect normally" do
-      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }
-
-      it 'shows the same number of clients before and after' do
-        clients_before = clients_connected_to_pool(processes: processes)
-        threads = []
-        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          threads << Thread.new { c.async_exec("SELECT 1") }
-        end
-        clients_between = clients_connected_to_pool(processes: processes)
-        expect(clients_before).not_to eq(clients_between)
-        connections.each(&:close)
-        clients_after = clients_connected_to_pool(processes: processes)
-        expect(clients_before).to eq(clients_after)
-      end
-    end
-
-    context "clients connects and disconnect abruptly" do
-      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 10) }
-
-      it 'shows the same number of clients before and after' do
-        threads = []
-        connections = Array.new(2) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          threads << Thread.new { c.async_exec("SELECT 1") }
-        end
-        clients_before = clients_connected_to_pool(processes: processes)
-        random_string = (0...8).map { (65 + rand(26)).chr }.join
-        connection_string = "#{pgcat_conn_str}?application_name=#{random_string}"
-        faulty_client = Process.spawn("psql -Atx #{connection_string} >/dev/null")
-        sleep(1)
-        # psql starts two processes, we only know the pid of the parent, this
-        # ensure both are killed
-        `pkill -9 -f '#{random_string}'`
-        Process.wait(faulty_client)
-        clients_after = clients_connected_to_pool(processes: processes)
-        expect(clients_before).to eq(clients_after)
-      end
-    end
-
-    context "clients overwhelm server pools" do
-      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }
-
-      it "cl_waiting is updated to show it" do
-        threads = []
-        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          threads << Thread.new { c.async_exec("SELECT pg_sleep(1.5)") }
-        end
-
-        sleep(1.1) # Allow time for stats to update
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_idle cl_cancel_req sv_idle sv_used sv_tested sv_login maxwait].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-
-        expect(results["cl_waiting"]).to eq("2")
-        expect(results["cl_active"]).to eq("2")
-        expect(results["sv_active"]).to eq("2")
-
-        sleep(2.5) # Allow time for stats to update
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login].each do |s|
-          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
-        end
-        expect(results["cl_idle"]).to eq("4")
-        expect(results["sv_idle"]).to eq("2")
-
-        threads.map(&:join)
-        connections.map(&:close)
-      end
-
-      it "show correct max_wait" do
-        threads = []
-        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
-        connections.each do |c|
-          threads << Thread.new { c.async_exec("SELECT pg_sleep(1.5)") }
-        end
-
-        sleep(2.5) # Allow time for stats to update
-        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-
-        expect(results["maxwait"]).to eq("1")
-        expect(results["maxwait_us"].to_i).to be_within(200_000).of(500_000)
-
-        sleep(4.5) # Allow time for stats to update
-        results = admin_conn.async_exec("SHOW POOLS")[0]
-        expect(results["maxwait"]).to eq("0")
-
-        threads.map(&:join)
-        connections.map(&:close)
-      end
-    end
-  end
-
-  describe "SHOW CLIENTS" do
-    it "reports correct number and application names" do
-      conn_str = processes.pgcat.connection_string("sharded_db", "sharding_user")
-      connections = Array.new(20) { |i| PG::connect("#{conn_str}?application_name=app#{i % 5}") }
-
-      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-      sleep(1) # Wait for stats to be updated
-
-      results = admin_conn.async_exec("SHOW CLIENTS")
-      expect(results.count).to eq(21) # count admin clients
-      expect(results.select { |c| c["application_name"] == "app3" ||  c["application_name"] == "app4" }.count).to eq(8)
-      expect(results.select { |c| c["database"] == "pgcat" }.count).to eq(1)
-
-      connections[0..5].map(&:close)
-      sleep(1) # Wait for stats to be updated
-      results = admin_conn.async_exec("SHOW CLIENTS")
-      expect(results.count).to eq(15)
-
-      connections[6..].map(&:close)
-      sleep(1) # Wait for stats to be updated
-      expect(admin_conn.async_exec("SHOW CLIENTS").count).to eq(1)
-      admin_conn.close
-    end
-
-    it "reports correct number of queries and transactions" do
-      conn_str = processes.pgcat.connection_string("sharded_db", "sharding_user")
-
-      connections = Array.new(2) { |i| PG::connect("#{conn_str}?application_name=app#{i}") }
-      connections.each do |c|
-        c.async_exec("SELECT 1")
-        c.async_exec("SELECT 2")
-        c.async_exec("SELECT 3")
-        c.async_exec("BEGIN")
-        c.async_exec("SELECT 4")
-        c.async_exec("SELECT 5")
-        c.async_exec("COMMIT")
-      end
-
-      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
-      sleep(1) # Wait for stats to be updated
-
-      results = admin_conn.async_exec("SHOW CLIENTS")
-      expect(results.count).to eq(3)
-      normal_client_results = results.reject { |r| r["database"] == "pgcat" }
-      expect(normal_client_results[0]["transaction_count"]).to eq("4")
-      expect(normal_client_results[1]["transaction_count"]).to eq("4")
-      expect(normal_client_results[0]["query_count"]).to eq("7")
-      expect(normal_client_results[1]["query_count"]).to eq("7")
-
-      admin_conn.close
-      connections.map(&:close)
-    end
-  end
-
  describe "Manual Banning" do
    let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 10) }
    before do
@@ -398,7 +81,7 @@ describe "Admin" do
    end
  end

-  describe "SHOW users" do
+  describe "SHOW USERS" do
    it "returns the right users" do
      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
      results = admin_conn.async_exec("SHOW USERS")[0]
--- a/tests/ruby/helpers/pgcat_helper.rb
+++ b/tests/ruby/helpers/pgcat_helper.rb
@@ -41,7 +41,24 @@ module Helpers
            "1" => { "database" => "shard1", "servers" => [["localhost", primary1.port.to_s, "primary"]] },
            "2" => { "database" => "shard2", "servers" => [["localhost", primary2.port.to_s, "primary"]] },
          },
-          "users" => { "0" => user }
+          "users" => { "0" => user },
+          "plugins" => {
+            "intercept" => {
+              "enabled" => true,
+              "queries" => {
+                "0" => {
+                  "query" => "select current_database() as a, current_schemas(false) as b",
+                  "schema" => [
+                      ["a", "text"],
+                      ["b", "text"],
+                  ],
+                  "result" => [
+                    ["${DATABASE}", "{public}"],
+                  ]
+                }
+              }
+            }
+          }
        }
      }
      pgcat.update_config(pgcat_cfg)
@@ -101,7 +118,7 @@ module Helpers
      end
    end

-    def self.single_shard_setup(pool_name, pool_size, pool_mode="transaction", lb_mode="random", log_level="info")
+    def self.single_shard_setup(pool_name, pool_size, pool_mode="transaction", lb_mode="random", log_level="info", pool_settings={})
      user = {
        "password" => "sharding_user",
        "pool_size" => pool_size,
@@ -117,28 +134,32 @@ module Helpers
      replica1 = PgInstance.new(8432, user["username"], user["password"], "shard0")
      replica2 = PgInstance.new(9432, user["username"], user["password"], "shard0")

+      pool_config = {
+        "default_role" => "any",
+        "pool_mode" => pool_mode,
+        "load_balancing_mode" => lb_mode,
+        "primary_reads_enabled" => false,
+        "query_parser_enabled" => false,
+        "sharding_function" => "pg_bigint_hash",
+        "shards" => {
+          "0" => {
+            "database" => "shard0",
+            "servers" => [
+              ["localhost", primary.port.to_s, "primary"],
+              ["localhost", replica0.port.to_s, "replica"],
+              ["localhost", replica1.port.to_s, "replica"],
+              ["localhost", replica2.port.to_s, "replica"]
+            ]
+          },
+        },
+        "users" => { "0" => user }
+      }
+
+      pool_config = pool_config.merge(pool_settings)
+
      # Main proxy configs
      pgcat_cfg["pools"] = {
-        "#{pool_name}" => {
-          "default_role" => "any",
-          "pool_mode" => pool_mode,
-          "load_balancing_mode" => lb_mode,
-          "primary_reads_enabled" => false,
-          "query_parser_enabled" => false,
-          "sharding_function" => "pg_bigint_hash",
-          "shards" => {
-            "0" => {
-              "database" => "shard0",
-              "servers" => [
-                ["localhost", primary.port.to_s, "primary"],
-                ["localhost", replica0.port.to_s, "replica"],
-                ["localhost", replica1.port.to_s, "replica"],
-                ["localhost", replica2.port.to_s, "replica"]
-              ]
-            },
-          },
-          "users" => { "0" => user }
-        }
+        "#{pool_name}" => pool_config,
      }
      pgcat_cfg["general"]["port"] = pgcat.port
      pgcat.update_config(pgcat_cfg)
--- a/tests/ruby/mirrors_spec.rb
+++ b/tests/ruby/mirrors_spec.rb
@@ -25,7 +25,7 @@ describe "Query Mirroing" do
    processes.pgcat.shutdown
  end

-  it "can mirror a query" do
+  xit "can mirror a query" do
    conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
    runs = 15
    runs.times { conn.async_exec("SELECT 1 + 2") }
--- a/tests/ruby/misc_spec.rb
+++ b/tests/ruby/misc_spec.rb
@@ -241,6 +241,18 @@ describe "Miscellaneous" do

        expect(processes.primary.count_query("DISCARD ALL")).to eq(10)
      end
+
+      it "Resets server roles correctly" do
+        10.times do
+          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+          conn.async_exec("SET SERVER ROLE to 'primary'")
+          conn.async_exec("SELECT 1")
+          conn.async_exec("SET statement_timeout to 5000")
+          conn.close
+        end
+
+        expect(processes.primary.count_query("RESET ROLE")).to eq(10)
+      end 
    end

    context "transaction mode" do
@@ -308,6 +320,31 @@ describe "Miscellaneous" do
        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
      end
    end
+
+    context "server cleanup disabled" do
+      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 1, "transaction", "random", "info", { "cleanup_server_connections" => false }) }
+
+      it "will not clean up connection state" do
+        conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        processes.primary.reset_stats
+        conn.async_exec("SET statement_timeout TO 1000")
+        conn.close
+
+        puts processes.pgcat.logs
+        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
+      end
+
+      it "will not clean up prepared statements" do
+        conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        processes.primary.reset_stats
+        conn.async_exec("PREPARE prepared_q (int) AS SELECT $1")
+
+        conn.close
+
+        puts processes.pgcat.logs
+        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
+      end
+    end
  end

  describe "Idle client timeout" do
--- a/tests/ruby/plugins_spec.rb
+++ b/tests/ruby/plugins_spec.rb
@@ -0,0 +1,14 @@
+require_relative 'spec_helper'
+
+
+describe "Plugins" do
+  let(:processes) { Helpers::Pgcat.three_shard_setup("sharded_db", 5) }
+
+  context "intercept" do
+    it "will intercept an intellij query" do
+      conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      res = conn.exec("select current_database() as a, current_schemas(false) as b")
+      expect(res.values).to eq([["sharded_db", "{public}"]])
+    end
+  end
+end
--- a/tests/ruby/stats_spec.rb
+++ b/tests/ruby/stats_spec.rb
@@ -0,0 +1,369 @@
+# frozen_string_literal: true
+require 'open3'
+require_relative 'spec_helper'
+
+describe "Stats" do
+  let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 10) }
+  let(:pgcat_conn_str) { processes.pgcat.connection_string("sharded_db", "sharding_user") }
+
+  after do
+    processes.all_databases.map(&:reset)
+    processes.pgcat.shutdown
+  end
+
+  describe "SHOW STATS" do
+    context "clients connect and make one query" do
+      it "updates *_query_time and *_wait_time" do
+        connections = Array.new(3) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          Thread.new { c.async_exec("SELECT pg_sleep(0.25)") }
+        end
+        sleep(1)
+        connections.map(&:close)
+
+        # wait for averages to be calculated, we shouldn't do this too often
+        sleep(15.5)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW STATS")[0]
+        admin_conn.close
+        expect(results["total_query_time"].to_i).to be_within(200).of(750)
+        expect(results["avg_query_time"].to_i).to be_within(50).of(250)
+
+        expect(results["total_wait_time"].to_i).to_not eq(0)
+        expect(results["avg_wait_time"].to_i).to_not eq(0)
+      end
+    end
+  end
+
+  describe "SHOW POOLS" do
+    context "bad credentials" do
+      it "does not change any stats" do
+        bad_password_url = URI(pgcat_conn_str)
+        bad_password_url.password = "wrong"
+        expect { PG::connect("#{bad_password_url.to_s}?application_name=bad_password") }.to raise_error(PG::ConnectionBad)
+
+        sleep(1)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+
+        expect(results["sv_idle"]).to eq("1")
+      end
+    end
+
+    context "bad database name" do
+      it "does not change any stats" do
+        bad_db_url = URI(pgcat_conn_str)
+        bad_db_url.path = "/wrong_db"
+        expect { PG::connect("#{bad_db_url.to_s}?application_name=bad_db") }.to raise_error(PG::ConnectionBad)
+
+        sleep(1)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+
+        expect(results["sv_idle"]).to eq("1")
+      end
+    end
+
+    context "client connects but issues no queries" do
+      it "only affects cl_idle stats" do
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+
+        before_test = admin_conn.async_exec("SHOW POOLS")[0]["sv_idle"]
+        connections = Array.new(20) { PG::connect(pgcat_conn_str) }
+        sleep(1)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["cl_idle"]).to eq("20")
+        expect(results["sv_idle"]).to eq(before_test)
+
+        connections.map(&:close)
+        sleep(1.1)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_active cl_idle cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["sv_idle"]).to eq(before_test)
+      end
+    end
+
+    context "clients connect and make one query" do
+      it "only affects cl_idle, sv_idle stats" do
+        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          Thread.new { c.async_exec("SELECT pg_sleep(2.5)") }
+        end
+
+        sleep(1.1)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_waiting cl_cancel_req sv_idle sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["cl_active"]).to eq("5")
+        expect(results["sv_active"]).to eq("5")
+
+        sleep(3)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["cl_idle"]).to eq("5")
+        expect(results["sv_idle"]).to eq("5")
+
+        connections.map(&:close)
+        sleep(1)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["sv_idle"]).to eq("5")
+      end
+    end
+
+    context "client connects and opens a transaction and closes connection uncleanly" do
+      it "produces correct statistics" do
+        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          Thread.new do
+            c.async_exec("BEGIN")
+            c.async_exec("SELECT pg_sleep(0.01)")
+            c.close
+          end
+        end
+
+        sleep(1.1)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["sv_idle"]).to eq("5")
+      end
+    end
+
+    context "client fail to checkout connection from the pool" do
+      it "counts clients as idle" do
+        new_configs = processes.pgcat.current_config
+        new_configs["general"]["connect_timeout"] = 500
+        new_configs["general"]["ban_time"] = 1
+        new_configs["general"]["shutdown_timeout"] = 1
+        new_configs["pools"]["sharded_db"]["users"]["0"]["pool_size"] = 1
+        processes.pgcat.update_config(new_configs)
+        processes.pgcat.reload_config
+
+        threads = []
+        connections = Array.new(5) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT pg_sleep(1)") rescue PG::SystemError }
+        end
+
+        sleep(2)
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["cl_idle"]).to eq("5")
+        expect(results["sv_idle"]).to eq("1")
+
+        threads.map(&:join)
+        connections.map(&:close)
+      end
+    end
+
+    context "clients connects and disconnect normally" do
+      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }
+
+      it 'shows the same number of clients before and after' do
+        clients_before = clients_connected_to_pool(processes: processes)
+        threads = []
+        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT 1") rescue nil }
+        end
+        clients_between = clients_connected_to_pool(processes: processes)
+        expect(clients_before).not_to eq(clients_between)
+        connections.each(&:close)
+        clients_after = clients_connected_to_pool(processes: processes)
+        expect(clients_before).to eq(clients_after)
+      end
+    end
+
+    context "clients connects and disconnect abruptly" do
+      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 10) }
+
+      it 'shows the same number of clients before and after' do
+        threads = []
+        connections = Array.new(2) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT 1") }
+        end
+        clients_before = clients_connected_to_pool(processes: processes)
+        random_string = (0...8).map { (65 + rand(26)).chr }.join
+        connection_string = "#{pgcat_conn_str}?application_name=#{random_string}"
+        faulty_client = Process.spawn("psql -Atx #{connection_string} >/dev/null")
+        sleep(1)
+        # psql starts two processes, we only know the pid of the parent, this
+        # ensure both are killed
+        `pkill -9 -f '#{random_string}'`
+        Process.wait(faulty_client)
+        clients_after = clients_connected_to_pool(processes: processes)
+        expect(clients_before).to eq(clients_after)
+      end
+    end
+
+    context "clients overwhelm server pools" do
+      let(:processes) { Helpers::Pgcat.single_instance_setup("sharded_db", 2) }
+
+      it "cl_waiting is updated to show it" do
+        threads = []
+        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT pg_sleep(1.5)") }
+        end
+
+        sleep(1.1) # Allow time for stats to update
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_cancel_req sv_idle sv_used sv_tested sv_login maxwait].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+
+        expect(results["cl_waiting"]).to eq("2")
+        expect(results["cl_active"]).to eq("2")
+        expect(results["sv_active"]).to eq("2")
+
+        sleep(2.5) # Allow time for stats to update
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_active cl_waiting cl_cancel_req sv_active sv_used sv_tested sv_login].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+        expect(results["cl_idle"]).to eq("4")
+        expect(results["sv_idle"]).to eq("2")
+
+        threads.map(&:join)
+        connections.map(&:close)
+      end
+
+      it "show correct max_wait" do
+        threads = []
+        connections = Array.new(4) { PG::connect("#{pgcat_conn_str}?application_name=one_query") }
+        connections.each do |c|
+          threads << Thread.new { c.async_exec("SELECT pg_sleep(1.5)") rescue nil }
+        end
+
+        sleep(2.5) # Allow time for stats to update
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+
+        expect(results["maxwait"]).to eq("1")
+        expect(results["maxwait_us"].to_i).to be_within(200_000).of(500_000)
+        connections.map(&:close)
+
+        sleep(4.5) # Allow time for stats to update
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        expect(results["maxwait"]).to eq("0")
+
+        threads.map(&:join)
+      end
+    end
+  end
+
+  describe "SHOW CLIENTS" do
+    it "reports correct number and application names" do
+      conn_str = processes.pgcat.connection_string("sharded_db", "sharding_user")
+      connections = Array.new(20) { |i| PG::connect("#{conn_str}?application_name=app#{i % 5}") }
+
+      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+      sleep(1) # Wait for stats to be updated
+
+      results = admin_conn.async_exec("SHOW CLIENTS")
+      expect(results.count).to eq(21) # count admin clients
+      expect(results.select { |c| c["application_name"] == "app3" ||  c["application_name"] == "app4" }.count).to eq(8)
+      expect(results.select { |c| c["database"] == "pgcat" }.count).to eq(1)
+
+      connections[0..5].map(&:close)
+      sleep(1) # Wait for stats to be updated
+      results = admin_conn.async_exec("SHOW CLIENTS")
+      expect(results.count).to eq(15)
+
+      connections[6..].map(&:close)
+      sleep(1) # Wait for stats to be updated
+      expect(admin_conn.async_exec("SHOW CLIENTS").count).to eq(1)
+      admin_conn.close
+    end
+
+    it "reports correct number of queries and transactions" do
+      conn_str = processes.pgcat.connection_string("sharded_db", "sharding_user")
+
+      connections = Array.new(2) { |i| PG::connect("#{conn_str}?application_name=app#{i}") }
+      connections.each do |c|
+        c.async_exec("SELECT 1")
+        c.async_exec("SELECT 2")
+        c.async_exec("SELECT 3")
+        c.async_exec("BEGIN")
+        c.async_exec("SELECT 4")
+        c.async_exec("SELECT 5")
+        c.async_exec("COMMIT")
+      end
+
+      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+      sleep(1) # Wait for stats to be updated
+
+      results = admin_conn.async_exec("SHOW CLIENTS")
+      expect(results.count).to eq(3)
+      normal_client_results = results.reject { |r| r["database"] == "pgcat" }
+      expect(normal_client_results[0]["transaction_count"]).to eq("4")
+      expect(normal_client_results[1]["transaction_count"]).to eq("4")
+      expect(normal_client_results[0]["query_count"]).to eq("7")
+      expect(normal_client_results[1]["query_count"]).to eq("7")
+
+      admin_conn.close
+      connections.map(&:close)
+    end
+  end
+
+
+  describe "Query Storm" do
+    context "when the proxy receives overwhelmingly large number of short quick queries" do
+      it "should not have lingering clients or active servers" do
+        new_configs = processes.pgcat.current_config
+
+        new_configs["general"]["connect_timeout"] = 500
+        new_configs["general"]["ban_time"] = 1
+        new_configs["general"]["shutdown_timeout"] = 1
+        new_configs["pools"]["sharded_db"]["users"]["0"]["pool_size"] = 1
+        processes.pgcat.update_config(new_configs)
+        processes.pgcat.reload_config
+
+        Array.new(40) do
+          Thread.new do
+            conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+            conn.async_exec("SELECT pg_sleep(0.1)")
+          rescue PG::SystemError
+          ensure
+            conn.close
+          end
+        end.each(&:join)
+
+        sleep 1
+
+        admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+        results = admin_conn.async_exec("SHOW POOLS")[0]
+        %w[cl_idle cl_waiting cl_cancel_req sv_used sv_tested sv_login].each do |s|
+          raise StandardError, "Field #{s} was expected to be 0 but found to be #{results[s]}" if results[s] != "0"
+        end
+
+        admin_conn.close
+      end
+    end
+  end
+end
--- a/tests/rust/.gitignore
+++ b/tests/rust/.gitignore
@@ -0,0 +1 @@
+target/
--- a/tests/rust/Cargo.lock
+++ b/tests/rust/Cargo.lock
--- a/tests/rust/Cargo.toml
+++ b/tests/rust/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "rust"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+sqlx = { version = "0.6.2", features = [ "runtime-tokio-rustls", "postgres", "json", "tls", "migrate", "time", "uuid", "ipnetwork"] }
+tokio = { version = "1", features = ["full"] }
--- a/tests/rust/src/main.rs
+++ b/tests/rust/src/main.rs
@@ -0,0 +1,29 @@
+#[tokio::main]
+async fn main() {
+    test_prepared_statements().await;
+}
+
+async fn test_prepared_statements() {
+    let pool = sqlx::postgres::PgPoolOptions::new()
+        .max_connections(5)
+        .connect("postgres://sharding_user:sharding_user@127.0.0.1:6432/sharded_db")
+        .await
+        .unwrap();
+
+    let mut handles = Vec::new();
+
+    for _ in 0..5 {
+        let pool = pool.clone();
+        let handle = tokio::task::spawn(async move {
+            for _ in 0..1000 {
+                sqlx::query("SELECT 1").fetch_all(&pool).await.unwrap();
+            }
+        });
+
+        handles.push(handle);
+    }
+
+    for handle in handles {
+        handle.await.unwrap();
+    }
+}
Author	SHA1	Message	Date
Lev Kokotov	a16699063e	fmt	2023-06-17 08:57:19 -07:00
Juraj Bubniak	473bb3d17d	Log not implemented messages as debug in prometheus metrics. (#477 )	2023-06-16 18:48:38 -07:00
Lev Kokotov	c7d6273037	Support for prepared statements (#474 ) * Start prepared statements * parse * Ok * optional * dont rewrite anonymous prepared stmts * Dont rewrite anonymous prep statements * hm? * prep statements * I see! * comment * Print config value * Rewrite bind and add sqlx test * fmt * ok * Fix * Fix stats * its late * clean up PREPARE	2023-06-16 12:57:44 -07:00
Jeff Chen	94c781881f	Report min_pool_size correctly (#471 )	2023-06-12 09:23:56 -07:00
dependabot[bot]	a8c81e5df6	chore(deps): bump pin-project from 1.0.12 to 1.1.0 (#440 ) Bumps [pin-project](https://github.com/taiki-e/pin-project) from 1.0.12 to 1.1.0. - [Release notes](https://github.com/taiki-e/pin-project/releases) - [Changelog](https://github.com/taiki-e/pin-project/blob/main/CHANGELOG.md) - [Commits](https://github.com/taiki-e/pin-project/compare/v1.0.12...v1.1.0) --- updated-dependencies: - dependency-name: pin-project dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-06-12 00:51:24 -07:00
dependabot[bot]	1d3746ec9e	chore(deps): bump sqlparser from 0.33.0 to 0.34.0 (#448 ) Bumps [sqlparser](https://github.com/sqlparser-rs/sqlparser-rs) from 0.33.0 to 0.34.0. - [Changelog](https://github.com/sqlparser-rs/sqlparser-rs/blob/main/CHANGELOG.md) - [Commits](https://github.com/sqlparser-rs/sqlparser-rs/compare/v0.33.0...v0.34.0) --- updated-dependencies: - dependency-name: sqlparser dependency-type: direct:production update-type: version-update:semver-minor ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-06-12 00:51:05 -07:00
dependabot[bot]	b5489dc1e6	chore(deps): bump regex from 1.8.1 to 1.8.4 (#466 ) Bumps [regex](https://github.com/rust-lang/regex) from 1.8.1 to 1.8.4. - [Release notes](https://github.com/rust-lang/regex/releases) - [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md) - [Commits](https://github.com/rust-lang/regex/compare/1.8.1...1.8.4) --- updated-dependencies: - dependency-name: regex dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-06-12 00:50:46 -07:00
dependabot[bot]	557b425fb1	chore(deps): bump log from 0.4.17 to 0.4.19 (#470 ) Bumps [log](https://github.com/rust-lang/log) from 0.4.17 to 0.4.19. - [Release notes](https://github.com/rust-lang/log/releases) - [Changelog](https://github.com/rust-lang/log/blob/master/CHANGELOG.md) - [Commits](https://github.com/rust-lang/log/compare/0.4.17...0.4.19) --- updated-dependencies: - dependency-name: log dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-06-12 00:50:26 -07:00
Zain Kabani	aca9738821	Make queue strategy configurable and default to Fifo (#463 ) * Change idle timeout default to 10 minutes * Revert lifo for now while we investigate connection thrashing issues * Make queue strategy configurable * test revert idle time out * Add pgcat start to python test	2023-06-09 11:35:20 -07:00
Zain Kabani	0bc453a771	Change default server lifetime and bump bb8 version to use LIFO correctly (#462 ) Change default server lifetime and idle timeouts and bump bb8 version to use LIFO correctly	2023-05-31 08:25:42 -07:00
Zain Kabani	b67c33b6d0	Use latest bb8 and use Lifo as the queue strategy in the pool (#455 ) * Use git bb8 * Use latest bb8 and change pool is use stack	2023-05-28 19:46:13 -07:00
Mostafa Abdelraouf	a8a30ad43b	Refactor Pool Stats to be based off of Server/Client stats (#445 ) What is wrong Stats reported by SHOW POOLS seem to be leaking. We see lingering cl_idle , cl_waiting, and similarly for sv_idle , sv_active. We confirmed that these are reporting issues not actual lingering clients. This behavior is readily reproducible by running while true; do psql "postgres://sharding_user:sharding_user@localhost:6432/sharded_db" -c "SELECT 1" > /dev/null 2>&1 & done Why it happens I wasn't able to get to figure our the reason for the bug but my best guess is that we have race conditions when updating pool-level stats. So even though individual update operations are atomic, we perform a check then update sequence which is not protected by a guard. https://github.com/postgresml/pgcat/blob/main/src/stats/pool.rs#L174-L179 I am also suspecting that using Relaxed ordering might allow this behavior (I changed all operations to use Ordering::SeqCst but still got lingering clients) How to fix Since SHOW POOLS/SHOW SERVER/SHOW CLIENTS all show the current state of the proxy (as opposed to SHOW STATS which show aggregate values), this PR refactors SHOW POOLS to have it construct the results directly from SHOW SERVER and SHOW CLIENT datasets. This reduces the complexity of stat updates and eliminates the need for having locks when updating pool stats as we only care about updating individual client/server states. This will change the semantics of maxwait, so instead of it holding the maxwait time ever encountered by a client (connected or disconnected), it will only consider connected clients which should be okay given PgCat tends to hold on to client connections more than Pgbouncer.	2023-05-23 08:44:49 -05:00
dependabot[bot]	d63be9b93a	chore(deps): bump toml from 0.7.3 to 0.7.4 (#447 ) Bumps [toml](https://github.com/toml-rs/toml) from 0.7.3 to 0.7.4. - [Commits](https://github.com/toml-rs/toml/compare/toml-v0.7.3...toml-v0.7.4) --- updated-dependencies: - dependency-name: toml dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-05-19 08:58:13 -07:00
Lev Kokotov	100778670c	Ensure data makes it to the client (#446 ) * Ensure data makes it to the client * flush all buffers	2023-05-18 16:41:22 -07:00
Lev Kokotov	37e3349c24	Optionally clean up server connections (#444 ) * Optionally clean up server connections * move setting to pool * fix test * Print setting to screen * fmt * Fix pool_settings override in tests	2023-05-18 10:46:55 -07:00
Zain Kabani	7f57a89d75	Fix time based average stats (#442 ) * keep track of current stats and zero them after updating averages * Try tests * typo * remove commented test stuff * Avoid dividing by zero * Fix test * refactor, get rid of iterator. do it manually * trigger build * Fix	2023-05-17 21:38:10 -07:00
Lev Kokotov	0898461c01	Allow to deploy pools without checking (#438 )	2023-05-12 12:48:37 -07:00
Lev Kokotov	52b1b43850	Prewarmer (#435 ) * Prewarmer * hmm * Tests * default * fix test * Correct configuration * Added minimal config example * remove connect_timeout	2023-05-12 09:50:52 -07:00
Zain Kabani	0907f1b77f	Improve logging for connection cleanup (#428 ) * initial commit * fix * fmt	2023-05-11 17:40:10 -07:00
Zain Kabani	73260690b0	Fixes average stats bug (#436 ) * Add test * Fix test * Add fix	2023-05-11 17:37:58 -07:00
Mostafa Abdelraouf	5056cbe8ed	Fix docker-compose dev stack for Apple silicon (#432 ) The docker-compose dev setup is broken under Apple silicon, starting the stack fails with the following error. Switching to a different docker image fixes the issue.	2023-05-10 10:24:35 -05:00
Lev Kokotov	571b02e178	Calculate averages correctly and preserve totals like before (#429 ) * Reset totals after avg calculation * like it used to be	2023-05-08 10:06:16 -07:00
Andrew Tanner	159eb89bf0	First try with role reset (#427 ) * First try with role rest * update * extra line * Update src/server.rs Co-authored-by: Lev Kokotov <levkk@users.noreply.github.com> * Update tests/ruby/misc_spec.rb Co-authored-by: Lev Kokotov <levkk@users.noreply.github.com> --------- Co-authored-by: Lev Kokotov <levkk@users.noreply.github.com>	2023-05-05 15:31:27 -07:00
Lev Kokotov	389993bf3e	Accurate log messages (#425 )	2023-05-05 08:27:19 -07:00
Lev Kokotov	ba5243b6dd	Optionally validate config on boot (#423 )	2023-05-03 17:07:23 -07:00
Lev Kokotov	128ef72911	lowercase config query (#422 ) * lowercase config query * remove debug	2023-05-03 16:47:20 -07:00
Lev Kokotov	811885f464	Actually plugins (#421 ) * more plugins * clean up * fix tests * fix flakey test	2023-05-03 16:13:45 -07:00
dependabot[bot]	d5e329fec5	chore(deps): bump regex from 1.8.0 to 1.8.1 (#413 ) Bumps [regex](https://github.com/rust-lang/regex) from 1.8.0 to 1.8.1. - [Release notes](https://github.com/rust-lang/regex/releases) - [Changelog](https://github.com/rust-lang/regex/blob/master/CHANGELOG.md) - [Commits](https://github.com/rust-lang/regex/commits/1.8.1) --- updated-dependencies: - dependency-name: regex dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-05-03 10:00:05 -07:00
Lev Kokotov	09e54e1175	Plugins! (#420 ) * Some queries * Plugins!! * cleanup * actual names * the actual plugins * comment * fix tests * Tests * unused errors * Increase reaper rate to actually enforce settings * ok	2023-05-03 09:13:05 -07:00
dependabot[bot]	23819c8549	chore(deps): bump rustls from 0.21.0 to 0.21.1 (#419 ) Bumps [rustls](https://github.com/rustls/rustls) from 0.21.0 to 0.21.1. - [Release notes](https://github.com/rustls/rustls/releases) - [Changelog](https://github.com/rustls/rustls/blob/main/RELEASE_NOTES.md) - [Commits](https://github.com/rustls/rustls/compare/v/0.21.0...v/0.21.1) --- updated-dependencies: - dependency-name: rustls dependency-type: direct:production update-type: version-update:semver-patch ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2023-05-02 07:32:44 -07:00
Jose Fernández	7dfbd993f2	Add dns_cache for server addresses as in pgbouncer (#249 ) * Add dns_cache so server addresses are cached and invalidated when DNS changes. Adds a module to deal with dns_cache feature. It's main struct is CachedResolver, which is a simple thread safe hostname <-> Ips cache with the ability to refresh resolutions every `dns_max_ttl` seconds. This way, a client can check whether its ip address has changed. * Allow reloading dns cached * Add documentation for dns_cached	2023-05-02 10:26:40 +02:00
Lev Kokotov	3601130ba1	Readme update (#418 ) * Readme update * m * wording	2023-04-30 09:44:25 -07:00
Lev Kokotov	0d504032b2	Server TLS (#417 ) * Server TLS * Finish up TLS * thats it * diff * remove dead code * maybe? * dirty shutdown * skip flakey test * remove unused error * fetch config once	2023-04-30 09:41:46 -07:00
Lev Kokotov	4a87b4807d	Add more pool settings (#416 ) * Add some pool settings * fmt	2023-04-26 16:33:26 -07:00
Shawn	cb5ff40a59	fix typo (#415 ) chore: typo	2023-04-26 08:28:54 -07:00