Fix broken custom config

* Add Discord link

* move it up

* :)

* hmm

* hmm

* :O

.circleci/config.yml

@@ -9,18 +9,40 @@ jobs:
     # Specify the execution environment. You can specify an image from Dockerhub or use one of our Convenience Images from CircleCI's Developer Hub.
     # See: https://circleci.com/docs/2.0/configuration-reference/#docker-machine-macos-windows-executor
     docker:
-      - image: cimg/rust:1.58.1
+      - image: levkk/pgcat-ci:latest
         environment:
           RUST_LOG: info
+          RUSTFLAGS: "-C instrument-coverage"
+          LLVM_PROFILE_FILE: "pgcat-%m.profraw"
       - image: postgres:14
-        # auth:
-        #   username: mydockerhub-user
-        #   password: $DOCKERHUB_PASSWORD
+        command: ["postgres", "-p", "5432", "-c", "shared_preload_libraries=pg_stat_statements"]
         environment:
           POSTGRES_USER: postgres
           POSTGRES_DB: postgres
           POSTGRES_PASSWORD: postgres
           POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+      - image: postgres:14
+        command: ["postgres", "-p", "7432", "-c", "shared_preload_libraries=pg_stat_statements"]
+        environment:
+          POSTGRES_USER: postgres
+          POSTGRES_DB: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+      - image: postgres:14
+        command: ["postgres", "-p", "8432", "-c", "shared_preload_libraries=pg_stat_statements"]
+        environment:
+          POSTGRES_USER: postgres
+          POSTGRES_DB: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+      - image: postgres:14
+        command: ["postgres", "-p", "9432", "-c", "shared_preload_libraries=pg_stat_statements"]
+        environment:
+          POSTGRES_USER: postgres
+          POSTGRES_DB: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+
     # Add steps to the job
     # See: https://circleci.com/docs/2.0/configuration-reference/#steps
     steps:
@@ -32,16 +54,19 @@ jobs:
           command: "cargo fmt --check"
       - run:
           name: "Install dependencies"
-          command: "sudo apt-get update && sudo apt-get install -y psmisc postgresql-contrib-12 postgresql-client-12 ruby ruby-dev libpq-dev"
+          command: "sudo apt-get update && sudo apt-get install -y psmisc postgresql-contrib-12 postgresql-client-12 ruby ruby-dev libpq-dev python3 python3-pip lcov llvm-11 && sudo apt-get upgrade curl"
       - run:
-          name: "Build" 
+          name: "Install rust tools"
+          command: "cargo install cargo-binutils rustfilt && rustup component add llvm-tools-preview"
+      - run:
+          name: "Build"
           command: "cargo build"
       - run:
-          name: "Test"
-          command: "cargo test"
-      - run:
-          name: "Test end-to-end"
-          command: "bash .circleci/run_tests.sh"
+          name: "Tests"
+          command: "cargo test && bash .circleci/run_tests.sh && .circleci/generate_coverage.sh"
+      - store_artifacts:
+          path: /tmp/cov
+          destination: coverage-data
       - save_cache:
           key: cargo-lock-2-{{ checksum "Cargo.lock" }}
           paths:

.circleci/generate_coverage.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+rust-profdata merge -sparse pgcat-*.profraw -o pgcat.profdata
+
+rust-cov export -ignore-filename-regex="rustc|registry" -Xdemangler=rustfilt -instr-profile=pgcat.profdata --object ./target/debug/pgcat --format lcov > ./lcov.info
+
+genhtml lcov.info --output-directory /tmp/cov --prefix $(pwd)

.circleci/pgcat.toml

@@ -5,74 +5,54 @@
 #
 # General pooler settings
 [general]
-
 # What IP to run on, 0.0.0.0 means accessible from everywhere.
 host = "0.0.0.0"
 
 # Port to run on, same as PgBouncer used in this example.
 port = 6432
 
-# How many connections to allocate per server.
-pool_size = 15
+# Whether to enable prometheus exporter or not.
+enable_prometheus_exporter = true
 
-# Pool mode (see PgBouncer docs for more).
-# session: one server connection per connected client
-# transaction: one server connection per client transaction
-pool_mode = "transaction"
+# Port at which prometheus exporter listens on.
+prometheus_exporter_port = 9930
 
 # How long to wait before aborting a server connection (ms).
 connect_timeout = 100
 
-# How much time to give `SELECT 1` health check query to return with a result (ms).
+# How much time to give the health check query to return with a result (ms).
 healthcheck_timeout = 100
 
+# How long to keep connection available for immediate re-use, without running a healthcheck query on it
+healthcheck_delay = 30000
+
+# How much time to give clients during shutdown before forcibly killing client connections (ms).
+shutdown_timeout = 5000
+
 # For how long to ban a server if it fails a health check (seconds).
 ban_time = 60 # Seconds
 
-#
-# User to use for authentication against the server.
-[user]
-name = "sharding_user"
-password = "sharding_user"
+# Reload config automatically if it changes.
+autoreload = true
 
+# TLS
+tls_certificate = ".circleci/server.cert"
+tls_private_key = ".circleci/server.key"
 
-#
-# Shards in the cluster
-[shards]
+# Credentials to access the virtual administrative database (pgbouncer or pgcat)
+# Connecting to that database allows running commands like `SHOW POOLS`, `SHOW DATABASES`, etc..
+admin_username = "admin_user"
+admin_password = "admin_pass"
 
-# Shard 0
-[shards.0]
-
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5433, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-# Database name (e.g. "postgres")
-database = "shard0"
-
-[shards.1]
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5433, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "shard1"
-
-[shards.2]
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5433, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "shard2"
-
-
-# Settings for our query routing layer.
-[query_router]
+# pool
+# configs are structured as pool.<pool_name>
+# the pool_name is what clients use as database name when connecting
+# For the example below a client can connect using "postgres://sharding_user:sharding_user@pgcat_host:pgcat_port/sharded_db"
+[pools.sharded_db]
+# Pool mode (see PgBouncer docs for more).
+# session: one server connection per connected client
+# transaction: one server connection per client transaction
+pool_mode = "transaction"
 
 # If the client doesn't specify, route traffic to
 # this role by default.
@@ -82,12 +62,11 @@ database = "shard2"
 # primary: all queries go to the primary unless otherwise specified.
 default_role = "any"
 
-
 # Query parser. If enabled, we'll attempt to parse
 # every incoming query to determine if it's a read or a write.
 # If it's a read query, we'll direct it to a replica. Otherwise, if it's a write,
 # we'll direct it to the primary.
-query_parser_enabled = false
+query_parser_enabled = true
 
 # If the query parser is enabled and this setting is enabled, the primary will be part of the pool of databases used for
 # load balancing of read queries. Otherwise, the primary will only be used for write
@@ -103,3 +82,64 @@ primary_reads_enabled = true
 # sha1: A hashing function based on SHA1
 #
 sharding_function = "pg_bigint_hash"
+
+# Credentials for users that may connect to this cluster
+[pools.sharded_db.users.0]
+username = "sharding_user"
+password = "sharding_user"
+# Maximum number of server connections that can be established for this user
+# The maximum number of connection from a single Pgcat process to any database in the cluster
+# is the sum of pool_size across all users.
+pool_size = 9
+statement_timeout = 0
+
+[pools.sharded_db.users.1]
+username = "other_user"
+password = "other_user"
+pool_size = 21
+statement_timeout = 30000
+
+# Shard 0
+[pools.sharded_db.shards.0]
+# [ host, port, role ]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ]
+]
+# Database name (e.g. "postgres")
+database = "shard0"
+
+[pools.sharded_db.shards.1]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ],
+]
+database = "shard1"
+
+[pools.sharded_db.shards.2]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ],
+]
+database = "shard2"
+
+
+[pools.simple_db]
+pool_mode = "session"
+default_role = "primary"
+query_parser_enabled = true
+primary_reads_enabled = true
+sharding_function = "pg_bigint_hash"
+
+[pools.simple_db.users.0]
+username = "simple_user"
+password = "simple_user"
+pool_size = 5
+statement_timeout = 30000
+
+[pools.simple_db.shards.0]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ]
+]
+database = "some_db"

.circleci/run_tests.sh

@@ -3,6 +3,9 @@
 set -e
 set -o xtrace
 
+# non-zero exit code if we provide bad configs
+(! ./target/debug/pgcat "fake_configs"  2>/dev/null)
+
 # Start PgCat with a particular log level
 # for inspection.
 function start_pgcat() {
@@ -13,17 +16,20 @@ function start_pgcat() {
 
 # Setup the database with shards and user
 PGPASSWORD=postgres psql -e -h 127.0.0.1 -p 5432 -U postgres -f tests/sharding/query_routing_setup.sql
+PGPASSWORD=postgres psql -e -h 127.0.0.1 -p 7432 -U postgres -f tests/sharding/query_routing_setup.sql
+PGPASSWORD=postgres psql -e -h 127.0.0.1 -p 8432 -U postgres -f tests/sharding/query_routing_setup.sql
+PGPASSWORD=postgres psql -e -h 127.0.0.1 -p 9432 -U postgres -f tests/sharding/query_routing_setup.sql
 
 PGPASSWORD=sharding_user pgbench -h 127.0.0.1 -U sharding_user shard0 -i
 PGPASSWORD=sharding_user pgbench -h 127.0.0.1 -U sharding_user shard1 -i
 PGPASSWORD=sharding_user pgbench -h 127.0.0.1 -U sharding_user shard2 -i
 
 # Install Toxiproxy to simulate a downed/slow database
-wget -O toxiproxy-2.1.4.deb https://github.com/Shopify/toxiproxy/releases/download/v2.1.4/toxiproxy_2.1.4_amd64.deb
-sudo dpkg -i toxiproxy-2.1.4.deb
+wget -O toxiproxy-2.4.0.deb https://github.com/Shopify/toxiproxy/releases/download/v2.4.0/toxiproxy_2.4.0_linux_$(dpkg --print-architecture).deb
+sudo dpkg -i toxiproxy-2.4.0.deb
 
 # Start Toxiproxy
-toxiproxy-server &
+LOG_LEVEL=error toxiproxy-server &
 sleep 1
 
 # Create a database at port 5433, forward it to Postgres
@@ -31,7 +37,11 @@ toxiproxy-cli create -l 127.0.0.1:5433 -u 127.0.0.1:5432 postgres_replica
 
 start_pgcat "info"
 
+# Check that prometheus is running
+curl --fail localhost:9930/metrics
+
 export PGPASSWORD=sharding_user
+export PGDATABASE=sharded_db
 
 # pgbench test
 pgbench -U sharding_user -i -h 127.0.0.1 -p 6432
@@ -42,7 +52,15 @@ pgbench -U sharding_user -h 127.0.0.1 -p 6432 -t 500 -c 2 --protocol extended
 psql -U sharding_user -h 127.0.0.1 -p 6432 -c 'COPY (SELECT * FROM pgbench_accounts LIMIT 15) TO STDOUT;' > /dev/null
 
 # Query cancellation test
-(psql -U sharding_user -h 127.0.0.1 -p 6432 -c 'SELECT pg_sleep(5)' || true) &
+(psql -U sharding_user -h 127.0.0.1 -p 6432 -c 'SELECT pg_sleep(50)' || true) &
+sleep 1
+killall psql -s SIGINT
+
+# Reload pool (closing unused server connections)
+PGPASSWORD=admin_pass psql -U admin_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'RELOAD'
+
+(psql -U sharding_user -h 127.0.0.1 -p 6432 -c 'SELECT pg_sleep(50)' || true) &
+sleep 1
 killall psql -s SIGINT
 
 # Sharding insert
@@ -54,25 +72,49 @@ psql -U sharding_user -e -h 127.0.0.1 -p 6432 -f tests/sharding/query_routing_te
 # Replica/primary selection & more sharding tests
 psql -U sharding_user -e -h 127.0.0.1 -p 6432 -f tests/sharding/query_routing_test_primary_replica.sql > /dev/null
 
+# Statement timeout tests
+sed -i 's/statement_timeout = 0/statement_timeout = 100/' .circleci/pgcat.toml
+kill -SIGHUP $(pgrep pgcat) # Reload config
+sleep 0.2
+
+# This should timeout
+(! psql -U sharding_user -e -h 127.0.0.1 -p 6432 -c 'select pg_sleep(0.5)')
+
+# Disable statement timeout
+sed -i 's/statement_timeout = 100/statement_timeout = 0/' .circleci/pgcat.toml
+kill -SIGHUP $(pgrep pgcat) # Reload config again
+
 #
 # ActiveRecord tests
 #
-cd tests/ruby && \
-    sudo gem install bundler && \
-    bundle install && \
-    ruby tests.rb && \
+cd tests/ruby
+sudo gem install bundler
+bundle install
+bundle exec ruby tests.rb || exit 1
+bundle exec rspec *_spec.rb || exit 1
 cd ../..
 
+#
+# Python tests
+# These tests will start and stop the pgcat server so it will need to be restarted after the tests
+#
+pip3 install -r tests/python/requirements.txt
+python3 tests/python/tests.py || exit 1
+
+start_pgcat "info"
+
 # Admin tests
-psql -U sharding_user -e -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW STATS' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'RELOAD' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW CONFIG' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW DATABASES' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW LISTS' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW POOLS' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW VERSION' > /dev/null
-psql -U sharding_user -h 127.0.0.1 -p 6432 -d pgbouncer -c "SET client_encoding TO 'utf8'" > /dev/null # will ignore
-(! psql -U sharding_user -e -h 127.0.0.1 -p 6432 -d random_db -c 'SHOW STATS' > /dev/null)
+export PGPASSWORD=admin_pass
+psql -U admin_user -e -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW STATS' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'RELOAD' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW CONFIG' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgbouncer -c 'SHOW DATABASES' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgcat -c 'SHOW LISTS' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgcat -c 'SHOW POOLS' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgcat -c 'SHOW VERSION' > /dev/null
+psql -U admin_user -h 127.0.0.1 -p 6432 -d pgbouncer -c "SET client_encoding TO 'utf8'" > /dev/null # will ignore
+(! psql -U admin_user -e -h 127.0.0.1 -p 6432 -d random_db -c 'SHOW STATS' > /dev/null)
+export PGPASSWORD=sharding_user
 
 # Start PgCat in debug to demonstrate failover better
 start_pgcat "trace"
@@ -94,11 +136,16 @@ toxiproxy-cli toxic remove --toxicName latency_downstream postgres_replica
 start_pgcat "info"
 
 # Test session mode (and config reload)
-sed -i 's/pool_mode = "transaction"/pool_mode = "session"/' pgcat.toml
+sed -i '0,/simple_db/s/pool_mode = "transaction"/pool_mode = "session"/' .circleci/pgcat.toml
 
 # Reload config test
 kill -SIGHUP $(pgrep pgcat)
 
+# Revert settings after reload. Makes test runs idempotent
+sed -i '0,/simple_db/s/pool_mode = "session"/pool_mode = "transaction"/' .circleci/pgcat.toml
+
+sleep 1
+
 # Prepared statements that will only work in session mode
 pgbench -U sharding_user -h 127.0.0.1 -p 6432 -t 500 -c 2 --protocol prepared
 

.circleci/server.cert

@@ -0,0 +1,21 @@
+-----BEGIN CERTIFICATE-----
+MIIDazCCAlOgAwIBAgIUChIvUGFJGJe5EDch32rchqoxER0wDQYJKoZIhvcNAQEL
+BQAwRTELMAkGA1UEBhMCQVUxEzARBgNVBAgMClNvbWUtU3RhdGUxITAfBgNVBAoM
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+f5+XAbN1Y+3OsFz/ZmP9
+-----END CERTIFICATE-----

.circleci/server.key

@@ -0,0 +1,28 @@
+-----BEGIN RSA PRIVATE KEY-----
+MIIEvwIBADANBgkqhkiG9w0BAQEFAASCBKkwggSlAgEAAoIBAQDdTwrBzV1v79fa
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+Qu2SrdPm5PYnKzpdynpz78OnGdflD1RKWFGHItR6GN6tj/VmulO6mlFvT4jzBQ7j
++Hf8m2TcD4U3ksz3xw+YOD+cmA==
+-----END RSA PRIVATE KEY-----

.gitignore

@@ -1,2 +1,4 @@
+.idea
 /target
 *.deb
+.vscode

CONTRIBUTING.md

@@ -10,10 +10,4 @@ Happy hacking!
 
 ## TODOs
 
-A non-exhaustive list of things that would be useful to implement:
-
-#### Client authentication
-MD5 is probably sufficient, but maybe others too.
-
-#### Admin
-Admin database for stats collection and pooler administration. PgBouncer gives us a nice example on how to do that, specifically how to implement `RowDescription` and `DataRow` messages, [example here](https://github.com/pgbouncer/pgbouncer/blob/4f9ced8e63d317a6ff45c8b0efa876b32161f6db/src/admin.c#L813).
+See [Issues]([url](https://github.com/levkk/pgcat/issues)).

Cargo.lock

@@ -79,12 +79,24 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "bumpalo"
+version = "3.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37ccbd214614c6783386c1af30caf03192f17891059cecc394b4fb119e363de3"
+
 [[package]]
 name = "bytes"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4872d67bab6358e59559027aa3b9157c53d9358c51423c17554809a8858e0f8"
 
+[[package]]
+name = "cc"
+version = "1.0.73"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fff2a6927b3bb87f9595d67196a70493f627687a71d87a0d692242c33f58c11"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -147,6 +159,18 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "exitcode"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de853764b47027c2e862a995c34978ffa63c1501f2e15f987ba11bd4f9bba193"
+
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
 [[package]]
 name = "futures-channel"
 version = "0.3.19"
@@ -162,6 +186,12 @@ version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0c8ff0461b82559810cdccfde3215c3f373807f5e5232b71479bff7bb2583d7"
 
+[[package]]
+name = "futures-sink"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21163e139fa306126e6eedaf49ecdb4588f939600f0b1e770f4205ee4b7fa868"
+
 [[package]]
 name = "futures-task"
 version = "0.3.19"
@@ -203,6 +233,31 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "h2"
+version = "0.3.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37a82c6d637fc9515a4694bbf1cb2457b79d81ce52b3108bdeea58b07dd34a57"
+dependencies = [
+ "bytes",
+ "fnv",
+ "futures-core",
+ "futures-sink",
+ "futures-util",
+ "http",
+ "indexmap",
+ "slab",
+ "tokio",
+ "tokio-util",
+ "tracing",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -221,12 +276,80 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "http"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75f43d41e26995c17e71ee126451dd3941010b0514a81a9d11f3b341debc2399"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d5f38f16d184e36f2408a55281cd658ecbd3ca05cce6d6510a176eca393e26d1"
+dependencies = [
+ "bytes",
+ "http",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "httparse"
+version = "1.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "496ce29bb5a52785b44e0f7ca2847ae0bb839c9bd28f69acac9b99d461c0c04c"
+
+[[package]]
+name = "httpdate"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4a1e36c821dbe04574f602848a19f742f4fb3c98d40449f11bcad18d6b17421"
+
 [[package]]
 name = "humantime"
 version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "hyper"
+version = "0.14.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02c929dc5c39e335a03c405292728118860721b10190d98c2a0f0efd5baafbac"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-core",
+ "futures-util",
+ "h2",
+ "http",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "socket2",
+ "tokio",
+ "tower-service",
+ "tracing",
+ "want",
+]
+
+[[package]]
+name = "indexmap"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10a35a97730320ffe8e2d410b5d3b69279b98d2c14bdb8b70ea89ecf7888d41e"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
+
 [[package]]
 name = "instant"
 version = "0.1.12"
@@ -237,10 +360,31 @@ dependencies = [
 ]
 
 [[package]]
-name = "libc"
-version = "0.2.117"
+name = "itoa"
+version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e74d72e0f9b65b5b4ca49a346af3976df0f9c61d550727f349ecd559f251a26c"
+checksum = "6c8af84674fe1f223a982c933a0ee1086ac4d4052aa0fb8060c12c6ad838e754"
+
+[[package]]
+name = "js-sys"
+version = "0.3.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3fac17f7123a73ca62df411b1bf727ccc805daa070338fda671c86dac1bdc27"
+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 = "0.2.126"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
 [[package]]
 name = "lock_api"
@@ -368,7 +512,7 @@ dependencies = [
 
 [[package]]
 name = "pgcat"
-version = "0.2.0-beta1"
+version = "0.6.0-alpha1"
 dependencies = [
  "arc-swap",
  "async-trait",
@@ -377,14 +521,18 @@ dependencies = [
  "bytes",
  "chrono",
  "env_logger",
+ "exitcode",
  "hmac",
+ "hyper",
  "log",
  "md-5",
  "num_cpus",
  "once_cell",
  "parking_lot",
+ "phf",
  "rand",
  "regex",
+ "rustls-pemfile",
  "serde",
  "serde_derive",
  "sha-1",
@@ -392,9 +540,54 @@ dependencies = [
  "sqlparser",
  "stringprep",
  "tokio",
+ "tokio-rustls",
  "toml",
 ]
 
+[[package]]
+name = "phf"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fabbf1ead8a5bcbc20f5f8b939ee3f5b0f6f281b6ad3468b84656b658b455259"
+dependencies = [
+ "phf_macros",
+ "phf_shared",
+ "proc-macro-hack",
+]
+
+[[package]]
+name = "phf_generator"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d5285893bb5eb82e6aaf5d59ee909a06a16737a8970984dd7746ba9283498d6"
+dependencies = [
+ "phf_shared",
+ "rand",
+]
+
+[[package]]
+name = "phf_macros"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58fdf3184dd560f160dd73922bea2d5cd6e8f064bf4b13110abd81b03697b4e0"
+dependencies = [
+ "phf_generator",
+ "phf_shared",
+ "proc-macro-hack",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "phf_shared"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6796ad771acdc0123d2a88dc428b5e38ef24456743ddb1744ed628f9815c096"
+dependencies = [
+ "siphasher",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.8"
@@ -413,6 +606,12 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.36"
@@ -497,12 +696,58 @@ version = "0.6.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
 
+[[package]]
+name = "ring"
+version = "0.16.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3053cf52e236a3ed746dfc745aa9cacf1b791d846bdaf412f60a8d7d6e17c8fc"
+dependencies = [
+ "cc",
+ "libc",
+ "once_cell",
+ "spin",
+ "untrusted",
+ "web-sys",
+ "winapi",
+]
+
+[[package]]
+name = "rustls"
+version = "0.20.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aab8ee6c7097ed6057f43c187a62418d0c05a4bd5f18b3571db50ee0f9ce033"
+dependencies = [
+ "log",
+ "ring",
+ "sct",
+ "webpki",
+]
+
+[[package]]
+name = "rustls-pemfile"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7522c9de787ff061458fe9a829dc790a3f5b22dc571694fc5883f448b94d9a9"
+dependencies = [
+ "base64",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "sct"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d53dcdb7c9f8158937a7981b48accfd39a43af418591a5d008c7b22b5e1b7ca4"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.136"
@@ -551,6 +796,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "siphasher"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7bd3e3206899af3f8b12af284fafc038cc1dc2b41d1b89dd17297221c5d225de"
+
 [[package]]
 name = "slab"
 version = "0.4.5"
@@ -563,6 +814,22 @@ version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f2dd574626839106c320a323308629dcb1acfc96e32a8cba364ddc61ac23ee83"
 
+[[package]]
+name = "socket2"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66d72b759436ae32898a2af0a14218dbf55efde3feeb170eb623637db85ee1e0"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "spin"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
+
 [[package]]
 name = "sqlparser"
 version = "0.14.0"
@@ -664,6 +931,31 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tokio-rustls"
+version = "0.23.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c43ee83903113e03984cb9e5cebe6c04a5116269e900e3ddba8f068a62adda59"
+dependencies = [
+ "rustls",
+ "tokio",
+ "webpki",
+]
+
+[[package]]
+name = "tokio-util"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f988a1a1adc2fb21f9c12aa96441da33a1728193ae0b95d2be22dbd17fcb4e5c"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "toml"
 version = "0.5.8"
@@ -673,6 +965,50 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "tower-service"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6bc1c9ce2b5135ac7f93c72918fc37feb872bdc6a5533a8b85eb4b86bfdae52"
+
+[[package]]
+name = "tracing"
+version = "0.1.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d0ecdcb44a79f0fe9844f0c4f33a342cbcbb5117de8001e6ba0dc2351327d09"
+dependencies = [
+ "cfg-if",
+ "pin-project-lite",
+ "tracing-attributes",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-attributes"
+version = "0.1.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11c75893af559bc8e10716548bdef5cb2b983f8e637db9d0e15126b61b484ee2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f54c8ca710e81886d498c2fd3331b56c93aa248d49de2222ad2742247c60072f"
+dependencies = [
+ "lazy_static",
+]
+
+[[package]]
+name = "try-lock"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
+
 [[package]]
 name = "typenum"
 version = "1.15.0"
@@ -700,18 +1036,108 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
+[[package]]
+name = "untrusted"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a156c684c91ea7d62626509bce3cb4e1d9ed5c4d978f7b4352658f96a4c26b4a"
+
 [[package]]
 name = "version_check"
 version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
+[[package]]
+name = "want"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ce8a968cb1cd110d136ff8b819a556d6fb6d919363c61534f6860c7eb172ba0"
+dependencies = [
+ "log",
+ "try-lock",
+]
+
 [[package]]
 name = "wasi"
 version = "0.10.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1a143597ca7c7793eff794def352d41792a93c481eb1042423ff7ff72ba2c31f"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.81"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c53b543413a17a202f4be280a7e5c62a1c69345f5de525ee64f8cfdbc954994"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.81"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5491a68ab4500fa6b4d726bd67408630c3dbe9c4fe7bda16d5c82a1fd8c7340a"
+dependencies = [
+ "bumpalo",
+ "lazy_static",
+ "log",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.81"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c441e177922bc58f1e12c022624b6216378e5febc2f0533e41ba443d505b80aa"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.81"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d94ac45fcf608c1f45ef53e748d35660f168490c10b23704c7779ab8f5c3048"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.81"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a89911bd99e5f3659ec4acf9c4d93b0a90fe4a2a11f15328472058edc5261be"
+
+[[package]]
+name = "web-sys"
+version = "0.3.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fed94beee57daf8dd7d51f2b15dc2bcde92d7a72304cdf662a4371008b71b90"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "webpki"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f095d78192e208183081cc07bc5515ef55216397af48b873e5edcd72637fa1bd"
+dependencies = [
+ "ring",
+ "untrusted",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pgcat"
-version = "0.2.1-beta1"
+version = "0.6.0-alpha1"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
@@ -28,4 +28,9 @@ parking_lot = "0.11"
 hmac = "0.12"
 sha2 = "0.10"
 base64 = "0.13"
-stringprep = "0.1"
+stringprep = "0.1"
+tokio-rustls = "0.23"
+rustls-pemfile = "1"
+hyper = { version = "0.14", features = ["full"] }
+phf = { version = "0.10", features = ["macros"] }
+exitcode = "1.1.2"

Dockerfile

@@ -1,9 +1,9 @@
-FROM rust:1.58-slim-buster AS builder
+FROM rust:1 AS builder
 COPY . /app
 WORKDIR /app
 RUN cargo build --release
 
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 COPY --from=builder /app/target/release/pgcat /usr/bin/pgcat
 COPY --from=builder /app/pgcat.toml /etc/pgcat/pgcat.toml
 WORKDIR /etc/pgcat

Dockerfile.ci

@@ -0,0 +1,8 @@
+FROM cimg/rust:1.62.0
+RUN sudo apt-get update && \
+	sudo apt-get install -y psmisc postgresql-contrib-12 postgresql-client-12 ruby ruby-dev libpq-dev python3 python3-pip lcov llvm-11 && \
+	sudo apt-get upgrade curl
+RUN cargo install cargo-binutils rustfilt && \
+	rustup component add llvm-tools-preview
+RUN pip3 install psycopg2 && \
+	sudo gem install bundler

README.md

@@ -1,8 +1,11 @@
-# PgCat
+![PgCat](./pgcat3.png)
+
+##### PgCat: PostgreSQL at petabyte scale
 
 [![CircleCI](https://circleci.com/gh/levkk/pgcat/tree/main.svg?style=svg)](https://circleci.com/gh/levkk/pgcat/tree/main)
-
-![PgCat](./pgcat3.png)
+<a href="https://discord.gg/DmyJP3qJ7U" target="_blank">
+    <img src="https://img.shields.io/discord/1013868243036930099" alt="Join our Discord!" />
+</a>
 
 PostgreSQL pooler (like PgBouncer) with sharding, load balancing and failover support.
 
@@ -15,7 +18,7 @@ PostgreSQL pooler (like PgBouncer) with sharding, load balancing and failover su
 | Session pooling                | :white_check_mark:          | Identical to PgBouncer.                                                                                                                               |
 | `COPY` support                 | :white_check_mark:          | Both `COPY TO` and `COPY FROM` are supported.                                                                                                         |
 | Query cancellation             | :white_check_mark:          | Supported both in transaction and session pooling modes.                                                                                              |
-| Load balancing of read queries | :white_check_mark:          | Using round-robin between replicas. Primary is included when `primary_reads_enabled` is enabled (default).                                            |
+| Load balancing of read queries | :white_check_mark:          | Using random between replicas. Primary is included when `primary_reads_enabled` is enabled (default).                                            |
 | Sharding                       | :white_check_mark:          | Transactions are sharded using `SET SHARD TO` and `SET SHARDING KEY TO` syntax extensions; see examples below.                                        |
 | Failover                       | :white_check_mark:          | Replicas are tested with a health check. If a health check fails, remaining replicas are attempted; see below for algorithm description and examples. |
 | Statistics                     | :white_check_mark:          | Statistics available in the admin database (`pgcat` and `pgbouncer`) with `SHOW STATS`, `SHOW POOLS` and others.                                      |
@@ -38,28 +41,34 @@ psql -h 127.0.0.1 -p 6432 -c 'SELECT 1'
 
 ### Config
 
-| **Name**                | **Description**                                                                                                                            | **Examples**                     |
-|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------|
-| **`general`**           |                                                                                                                                            |                                  |
-| `host`                  | The pooler will run on this host, 0.0.0.0 means accessible from everywhere.                                                                | `0.0.0.0`                        |
-| `port`                  | The pooler will run on this port.                                                                                                          | `6432`                           |
-| `pool_size`             | Maximum allowed server connections per pool. Pools are separated for each user/shard/server role. The connections are allocated as needed. | `15`                             |
-| `pool_mode`             | The pool mode to use, i.e. `session` or `transaction`.                                                                                     | `transaction`                    |
-| `connect_timeout`       | Maximum time to establish a connection to a server (milliseconds). If reached, the server is banned and the next target is attempted.      | `5000`                           |
-| `healthcheck_timeout`   | Maximum time to pass a health check (`SELECT 1`, milliseconds). If reached, the server is banned and the next target is attempted.         | `1000`                           |
-| `ban_time`              | Ban time for a server (seconds). It won't be allowed to serve transactions until the ban expires; failover targets will be used instead.   | `60`                             |
-|                         |                                                                                                                                            |                                  |
-| **`user`**              |                                                                                                                                            |                                  |
-| `name`                  | The user name.                                                                                                                             | `sharding_user`                  |
-| `password`              | The user password in plaintext.                                                                                                            | `hunter2`                        |
-|                         |                                                                                                                                            |                                  |
-| **`shards`**            | Shards are numerically numbered starting from 0; the order in the config is preserved by the pooler to route queries accordingly.          | `[shards.0]`                     |
-| `servers`               | List of servers to connect to and their roles. A server is: `[host, port, role]`, where `role` is either `primary` or `replica`.           | `["127.0.0.1", 5432, "primary"]` |
-| `database`              | The name of the database to connect to. This is the same on all servers that are part of one shard.                                        |                                  |
-| **`query_router`**      |                                                                                                                                            |                                  |
-| `default_role`          | Traffic is routed to this role by default (round-robin), unless the client specifies otherwise. Default is `any`, for any role available.  | `any`, `primary`, `replica`      |
-| `query_parser_enabled`  | Enable the query parser which will inspect incoming queries and route them to a primary or replicas.                                       | `false`                          |
-| `primary_reads_enabled` | Enable this to allow read queries on the primary; otherwise read queries are routed to the replicas.                                       | `true`                           |
+| **Name**                     | **Description**                                                                                                                            | **Examples**                     |
+|------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------|
+| **`general`**                |                                                                                                                                            |                                  |
+| `host`                       | The pooler will run on this host, 0.0.0.0 means accessible from everywhere.                                                                | `0.0.0.0`                        |
+| `port`                       | The pooler will run on this port.                                                                                                          | `6432`                           |
+| `enable_prometheus_exporter` | Enable prometheus exporter which will export metrics in prometheus exposition format.                                                      | `true`                           |
+| `prometheus_exporter_port`   | Port at which prometheus exporter listens on.                                                                                              | `9930`                           |
+| `pool_size`                  | Maximum allowed server connections per pool. Pools are separated for each user/shard/server role. The connections are allocated as needed. | `15`                             |
+| `pool_mode`                  | The pool mode to use, i.e. `session` or `transaction`.                                                                                     | `transaction`                    |
+| `connect_timeout`            | Maximum time to establish a connection to a server (milliseconds). If reached, the server is banned and the next target is attempted.      | `5000`                           |
+| `healthcheck_timeout`        | Maximum time to pass a health check (`SELECT 1`, milliseconds). If reached, the server is banned and the next target is attempted.         | `1000`                           |
+| `shutdown_timeout`           | Maximum time to give clients during shutdown before forcibly killing client connections (ms).                                              | `60000`                          |
+| `healthcheck_delay`          | How long to keep connection available for immediate re-use, without running a healthcheck query on it                                      | `30000`                          |
+| `ban_time`                   | Ban time for a server (seconds). It won't be allowed to serve transactions until the ban expires; failover targets will be used instead.   | `60`                             |
+| `autoreload`                 | Enable auto-reload of config after fixed time-interval.                                                                                    | `false`                          |
+|                              |                                                                                                                                            |                                  |
+| **`user`**                   |                                                                                                                                            |                                  |
+| `name`                       | The user name.                                                                                                                             | `sharding_user`                  |
+| `password`                   | The user password in plaintext.                                                                                                            | `hunter2`                        |
+|                              |                                                                                                                                            |                                  |
+| **`shards`**                 | Shards are numerically numbered starting from 0; the order in the config is preserved by the pooler to route queries accordingly.          | `[shards.0]`                     |
+| `servers`                    | List of servers to connect to and their roles. A server is: `[host, port, role]`, where `role` is either `primary` or `replica`.           | `["127.0.0.1", 5432, "primary"]` |
+| `database`                   | The name of the database to connect to. This is the same on all servers that are part of one shard.                                        |                                  |
+|                              |                                                                                                                                            |                                  |
+| **`query_router`**           |                                                                                                                                            |                                  |
+| `default_role`               | Traffic is routed to this role by default (random), unless the client specifies otherwise. Default is `any`, for any role available.  | `any`, `primary`, `replica`      |
+| `query_parser_enabled`       | Enable the query parser which will inspect incoming queries and route them to a primary or replicas.                                       | `false`                          |
+| `primary_reads_enabled`      | Enable this to allow read queries on the primary; otherwise read queries are routed to the replicas.                                       | `true`                           |
 
 ## Local development
 
@@ -81,6 +90,14 @@ pgbench -t 1000 -p 6432 -h 127.0.0.1 --protocol extended
 
 See [sharding README](./tests/sharding/README.md) for sharding logic testing.
 
+Run `cargo test` to run Rust tests.
+
+Run the following commands to run Integration tests locally.
+```
+cd tests/docker/
+docker compose up --exit-code-from main # This will also produce coverage report under ./cov/
+```
+
 | **Feature**           | **Tested in CI**   | **Tested manually** | **Comments**                                                                                                             |
 |-----------------------|--------------------|---------------------|--------------------------------------------------------------------------------------------------------------------------|
 | Transaction pooling   | :white_check_mark: | :white_check_mark:  | Used by default for all tests.                                                                                           |
@@ -106,7 +123,7 @@ In transaction mode, a client talks to one server for the duration of a single t
 This mode is enabled by default.
 
 ### Load balancing of read queries
-All queries are load balanced against the configured servers using the round-robin algorithm. The most straight forward configuration example would be to put this pooler in front of several replicas and let it load balance all queries.
+All queries are load balanced against the configured servers using the random algorithm. The most straight forward configuration example would be to put this pooler in front of several replicas and let it load balance all queries.
 
 If the configuration includes a primary and replicas, the queries can be separated with the built-in query parser. The query parser will interpret the query and route all `SELECT` queries to a replica, while all other queries including explicit transactions will be routed to the primary.
 
@@ -145,18 +162,18 @@ Failover behavior can get pretty interesting (read complex) when multiple config
 
 | **Query**                 | **`SET SERVER ROLE TO`** | **`query_parser_enabled`** | **`primary_reads_enabled`** | **Target state** | **Outcome**                                                                                                                                                          |
 |---------------------------|--------------------------|----------------------------|-----------------------------|------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| Read query, i.e. `SELECT` | unset (any)              | false                      | false                       | up               | Query is routed to the first instance in the round-robin loop.                                                                                                       |
-| Read query                | unset (any)              | true                       | false                       | up               | Query is routed to the first replica instance in the round-robin loop.                                                                                               |
-| Read query                | unset (any)              | true                       | true                        | up               | Query is routed to the first instance in the round-robin loop.                                                                                                       |
-| Read query                | replica                  | false                      | false                       | up               | Query is routed to the first replica instance in the round-robin loop.                                                                                               |
+| Read query, i.e. `SELECT` | unset (any)              | false                      | false                       | up               | Query is routed to the first instance in the random loop.                                                                                                       |
+| Read query                | unset (any)              | true                       | false                       | up               | Query is routed to the first replica instance in the random loop.                                                                                               |
+| Read query                | unset (any)              | true                       | true                        | up               | Query is routed to the first instance in the random loop.                                                                                                       |
+| Read query                | replica                  | false                      | false                       | up               | Query is routed to the first replica instance in the random loop.                                                                                               |
 | Read query                | primary                  | false                      | false                       | up               | Query is routed to the primary.                                                                                                                                      |
-| Read query                | unset (any)              | false                      | false                       | down             | First instance is banned for reads. Next target in the round-robin loop is attempted.                                                                                |
-| Read query                | unset (any)              | true                       | false                       | down             | First replica instance is banned. Next replica instance is attempted in the round-robin loop.                                                                        |
-| Read query                | unset (any)              | true                       | true                        | down             | First instance (even if primary) is banned for reads. Next instance is attempted in the round-robin loop.                                                            |
-| Read query                | replica                  | false                      | false                       | down             | First replica instance is banned. Next replica instance is attempted in the round-robin loop.                                                                        |
+| Read query                | unset (any)              | false                      | false                       | down             | First instance is banned for reads. Next target in the random loop is attempted.                                                                                |
+| Read query                | unset (any)              | true                       | false                       | down             | First replica instance is banned. Next replica instance is attempted in the random loop.                                                                        |
+| Read query                | unset (any)              | true                       | true                        | down             | First instance (even if primary) is banned for reads. Next instance is attempted in the random loop.                                                            |
+| Read query                | replica                  | false                      | false                       | down             | First replica instance is banned. Next replica instance is attempted in the random loop.                                                                        |
 | Read query                | primary                  | false                      | false                       | down             | The query is attempted against the primary and fails. The client receives an error.                                                                                  |
 |                           |                          |                            |                             |                  |                                                                                                                                                                      |
-| Write query e.g. `INSERT` | unset (any)              | false                      | false                       | up               | The query is attempted against the first available instance in the round-robin loop. If the instance is a replica, the query fails and the client receives an error. |
+| Write query e.g. `INSERT` | unset (any)              | false                      | false                       | up               | The query is attempted against the first available instance in the random loop. If the instance is a replica, the query fails and the client receives an error. |
 | Write query               | unset (any)              | true                       | false                       | up               | The query is routed to the primary.                                                                                                                                  |
 | Write query               | unset (any)              | true                       | true                        | up               | The query is routed to the primary.                                                                                                                                  |
 | Write query               | primary                  | false                      | false                       | up               | The query is routed to the primary.                                                                                                                                  |
@@ -250,6 +267,8 @@ The config can be reloaded by sending a `kill -s SIGHUP` to the process or by qu
 | `pool_mode`             | no                   |
 | `connect_timeout`       | yes                  |
 | `healthcheck_timeout`   | no                   |
+| `shutdown_timeout`      | no                   |
+| `healthcheck_delay`     | no                   |
 | `ban_time`              | no                   |
 | `user`                  | yes                  |
 | `shards`                | yes                  |
@@ -439,7 +458,7 @@ Always good to have a base line.
 
 ```
 $ pgbench -t 1000 -c 16 -j 2 -p 5432 -h 127.0.0.1 -S --protocol extended shard0
-Password: 
+Password:
 starting vacuum...end.
 transaction type: <builtin: select only>
 scaling factor: 1
@@ -453,7 +472,7 @@ tps = 139443.955722 (including connections establishing)
 tps = 142314.859075 (excluding connections establishing)
 
 $ pgbench -t 1000 -c 32 -j 2 -p 5432 -h 127.0.0.1 -S --protocol extended shard0
-Password: 
+Password:
 starting vacuum...end.
 transaction type: <builtin: select only>
 scaling factor: 1
@@ -467,7 +486,7 @@ tps = 150644.840891 (including connections establishing)
 tps = 152218.499430 (excluding connections establishing)
 
 $ pgbench -t 1000 -c 64 -j 2 -p 5432 -h 127.0.0.1 -S --protocol extended shard0
-Password: 
+Password:
 starting vacuum...end.
 transaction type: <builtin: select only>
 scaling factor: 1
@@ -481,7 +500,7 @@ tps = 152517.663404 (including connections establishing)
 tps = 153319.188482 (excluding connections establishing)
 
 $ pgbench -t 1000 -c 128 -j 2 -p 5432 -h 127.0.0.1 -S --protocol extended shard0
-Password: 
+Password:
 starting vacuum...end.
 transaction type: <builtin: select only>
 scaling factor: 1

docker-compose.yml

@@ -1,7 +1,7 @@
 version: "3"
 services:
   postgres:
-    image: postgres:13
+    image: postgres:14
     environment:
       POSTGRES_PASSWORD: postgres
       POSTGRES_HOST_AUTH_METHOD: md5
@@ -14,3 +14,4 @@ services:
       - "${PWD}/examples/docker/pgcat.toml:/etc/pgcat/pgcat.toml"
     ports:
       - "6432:6432"
+      - "9930:9930"

examples/docker/pgcat.toml

@@ -5,20 +5,17 @@
 #
 # General pooler settings
 [general]
-
 # What IP to run on, 0.0.0.0 means accessible from everywhere.
 host = "0.0.0.0"
 
 # Port to run on, same as PgBouncer used in this example.
 port = 6432
 
-# How many connections to allocate per server.
-pool_size = 15
+# Whether to enable prometheus exporter or not.
+enable_prometheus_exporter = true
 
-# Pool mode (see PgBouncer docs for more).
-# session: one server connection per connected client
-# transaction: one server connection per client transaction
-pool_mode = "transaction"
+# Port at which prometheus exporter listens on.
+prometheus_exporter_port = 9930
 
 # How long to wait before aborting a server connection (ms).
 connect_timeout = 5000
@@ -26,53 +23,36 @@ connect_timeout = 5000
 # How much time to give `SELECT 1` health check query to return with a result (ms).
 healthcheck_timeout = 1000
 
+# How long to keep connection available for immediate re-use, without running a healthcheck query on it
+healthcheck_delay = 30000
+
+# How much time to give clients during shutdown before forcibly killing client connections (ms).
+shutdown_timeout = 60000
+
 # For how long to ban a server if it fails a health check (seconds).
-ban_time = 60 # Seconds
+ban_time = 60 # seconds
 
-#
-# User to use for authentication against the server.
-[user]
-name = "postgres"
-password = "postgres"
+# Reload config automatically if it changes.
+autoreload = false
 
+# TLS
+# tls_certificate = "server.cert"
+# tls_private_key = "server.key"
 
-#
-# Shards in the cluster
-[shards]
+# Credentials to access the virtual administrative database (pgbouncer or pgcat)
+# Connecting to that database allows running commands like `SHOW POOLS`, `SHOW DATABASES`, etc..
+admin_username = "postgres"
+admin_password = "postgres"
 
-# Shard 0
-[shards.0]
-
-# [ host, port, role ]
-servers = [
-    [ "postgres", 5432, "primary" ],
-    [ "postgres", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-# Database name (e.g. "postgres")
-database = "postgres"
-
-[shards.1]
-# [ host, port, role ]
-servers = [
-    [ "postgres", 5432, "primary" ],
-    [ "postgres", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "postgres"
-
-[shards.2]
-# [ host, port, role ]
-servers = [
-    [ "postgres", 5432, "primary" ],
-    [ "postgres", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "postgres"
-
-
-# Settings for our query routing layer.
-[query_router]
+# pool
+# configs are structured as pool.<pool_name>
+# the pool_name is what clients use as database name when connecting
+# For the example below a client can connect using "postgres://sharding_user:sharding_user@pgcat_host:pgcat_port/sharded"
+[pools.sharded]
+# Pool mode (see PgBouncer docs for more).
+# session: one server connection per connected client
+# transaction: one server connection per client transaction
+pool_mode = "transaction"
 
 # If the client doesn't specify, route traffic to
 # this role by default.
@@ -82,12 +62,11 @@ database = "postgres"
 # primary: all queries go to the primary unless otherwise specified.
 default_role = "any"
 
-
 # Query parser. If enabled, we'll attempt to parse
 # every incoming query to determine if it's a read or a write.
 # If it's a read query, we'll direct it to a replica. Otherwise, if it's a write,
 # we'll direct it to the primary.
-query_parser_enabled = false
+query_parser_enabled = true
 
 # If the query parser is enabled and this setting is enabled, the primary will be part of the pool of databases used for
 # load balancing of read queries. Otherwise, the primary will only be used for write
@@ -103,3 +82,66 @@ primary_reads_enabled = true
 # sha1: A hashing function based on SHA1
 #
 sharding_function = "pg_bigint_hash"
+
+# Credentials for users that may connect to this cluster
+[pools.sharded.users.0]
+username = "postgres"
+password = "postgres"
+# Maximum number of server connections that can be established for this user
+# The maximum number of connection from a single Pgcat process to any database in the cluster
+# is the sum of pool_size across all users.
+pool_size = 9
+
+# Maximum query duration. Dangerous, but protects against DBs that died in a non-obvious way.
+statement_timeout = 0
+
+[pools.sharded.users.1]
+username = "postgres"
+password = "postgres"
+pool_size = 21
+statement_timeout = 15000
+
+# Shard 0
+[pools.sharded.shards.0]
+# [ host, port, role ]
+servers = [
+    [ "postgres", 5432, "primary" ],
+    [ "postgres", 5432, "replica" ]
+]
+# Database name (e.g. "postgres")
+database = "postgres"
+
+[pools.sharded.shards.1]
+servers = [
+    [ "postgres", 5432, "primary" ],
+    [ "postgres", 5432, "replica" ],
+]
+database = "postgres"
+
+[pools.sharded.shards.2]
+servers = [
+    [ "postgres", 5432, "primary" ],
+    [ "postgres", 5432, "replica" ],
+]
+database = "postgres"
+
+
+[pools.simple_db]
+pool_mode = "session"
+default_role = "primary"
+query_parser_enabled = true
+primary_reads_enabled = true
+sharding_function = "pg_bigint_hash"
+
+[pools.simple_db.users.0]
+username = "postgres"
+password = "postgres"
+pool_size = 5
+statement_timeout = 0
+
+[pools.simple_db.shards.0]
+servers = [
+    [ "postgres", 5432, "primary" ],
+    [ "postgres", 5432, "replica" ]
+]
+database = "postgres"

pgcat.toml

@@ -5,74 +5,54 @@
 #
 # General pooler settings
 [general]
-
 # What IP to run on, 0.0.0.0 means accessible from everywhere.
 host = "0.0.0.0"
 
 # Port to run on, same as PgBouncer used in this example.
 port = 6432
 
-# How many connections to allocate per server.
-pool_size = 15
+# Whether to enable prometheus exporter or not.
+enable_prometheus_exporter = true
 
-# Pool mode (see PgBouncer docs for more).
-# session: one server connection per connected client
-# transaction: one server connection per client transaction
-pool_mode = "transaction"
+# Port at which prometheus exporter listens on.
+prometheus_exporter_port = 9930
 
 # How long to wait before aborting a server connection (ms).
 connect_timeout = 5000
 
-# How much time to give `SELECT 1` health check query to return with a result (ms).
+# How much time to give the health check query to return with a result (ms).
 healthcheck_timeout = 1000
 
+# How long to keep connection available for immediate re-use, without running a healthcheck query on it
+healthcheck_delay = 30000
+
+# How much time to give clients during shutdown before forcibly killing client connections (ms).
+shutdown_timeout = 60000
+
 # For how long to ban a server if it fails a health check (seconds).
-ban_time = 60 # Seconds
+ban_time = 60 # seconds
 
-#
-# User to use for authentication against the server.
-[user]
-name = "sharding_user"
-password = "sharding_user"
+# Reload config automatically if it changes.
+autoreload = false
 
+# TLS
+# tls_certificate = "server.cert"
+# tls_private_key = "server.key"
 
-#
-# Shards in the cluster
-[shards]
+# Credentials to access the virtual administrative database (pgbouncer or pgcat)
+# Connecting to that database allows running commands like `SHOW POOLS`, `SHOW DATABASES`, etc..
+admin_username = "admin_user"
+admin_password = "admin_pass"
 
-# Shard 0
-[shards.0]
-
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-# Database name (e.g. "postgres")
-database = "shard0"
-
-[shards.1]
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "shard1"
-
-[shards.2]
-# [ host, port, role ]
-servers = [
-    [ "127.0.0.1", 5432, "primary" ],
-    [ "localhost", 5432, "replica" ],
-    # [ "127.0.1.1", 5432, "replica" ],
-]
-database = "shard2"
-
-
-# Settings for our query routing layer.
-[query_router]
+# pool
+# configs are structured as pool.<pool_name>
+# the pool_name is what clients use as database name when connecting
+# For the example below a client can connect using "postgres://sharding_user:sharding_user@pgcat_host:pgcat_port/sharded_db"
+[pools.sharded_db]
+# Pool mode (see PgBouncer docs for more).
+# session: one server connection per connected client
+# transaction: one server connection per client transaction
+pool_mode = "transaction"
 
 # If the client doesn't specify, route traffic to
 # this role by default.
@@ -82,16 +62,15 @@ database = "shard2"
 # primary: all queries go to the primary unless otherwise specified.
 default_role = "any"
 
-
 # Query parser. If enabled, we'll attempt to parse
 # every incoming query to determine if it's a read or a write.
 # If it's a read query, we'll direct it to a replica. Otherwise, if it's a write,
 # we'll direct it to the primary.
-query_parser_enabled = false
+query_parser_enabled = true
 
 # If the query parser is enabled and this setting is enabled, the primary will be part of the pool of databases used for
 # load balancing of read queries. Otherwise, the primary will only be used for write
-# queries. The primary can always be explicitely selected with our custom protocol.
+# queries. The primary can always be explicitly selected with our custom protocol.
 primary_reads_enabled = true
 
 # So what if you wanted to implement a different hashing function,
@@ -103,3 +82,67 @@ primary_reads_enabled = true
 # sha1: A hashing function based on SHA1
 #
 sharding_function = "pg_bigint_hash"
+sharding_key = "id"
+
+# Credentials for users that may connect to this cluster
+[pools.sharded_db.users.0]
+username = "sharding_user"
+password = "sharding_user"
+# Maximum number of server connections that can be established for this user
+# The maximum number of connection from a single Pgcat process to any database in the cluster
+# is the sum of pool_size across all users.
+pool_size = 9
+
+# Maximum query duration. Dangerous, but protects against DBs that died in a non-obvious way.
+statement_timeout = 0
+
+[pools.sharded_db.users.1]
+username = "other_user"
+password = "other_user"
+pool_size = 21
+statement_timeout = 15000
+
+# Shard 0
+[pools.sharded_db.shards.0]
+# [ host, port, role ]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ]
+]
+# Database name (e.g. "postgres")
+database = "shard0"
+
+[pools.sharded_db.shards.1]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ],
+]
+database = "shard1"
+
+[pools.sharded_db.shards.2]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ],
+]
+database = "shard2"
+
+
+[pools.simple_db]
+pool_mode = "session"
+default_role = "primary"
+query_parser_enabled = true
+primary_reads_enabled = true
+sharding_function = "pg_bigint_hash"
+
+[pools.simple_db.users.0]
+username = "simple_user"
+password = "simple_user"
+pool_size = 5
+statement_timeout = 0
+
+[pools.simple_db.shards.0]
+servers = [
+    [ "127.0.0.1", 5432, "primary" ],
+    [ "localhost", 5432, "replica" ]
+]
+database = "some_db"

src/admin.rs

@@ -2,20 +2,35 @@
 use bytes::{Buf, BufMut, BytesMut};
 use log::{info, trace};
 use std::collections::HashMap;
-use tokio::net::tcp::OwnedWriteHalf;
 
-use crate::config::{get_config, parse};
+use crate::config::{get_config, reload_config, VERSION};
 use crate::errors::Error;
 use crate::messages::*;
-use crate::pool::ConnectionPool;
+use crate::pool::get_all_pools;
 use crate::stats::get_stats;
+use crate::ClientServerMap;
+
+pub fn generate_server_info_for_admin() -> BytesMut {
+    let mut server_info = BytesMut::new();
+
+    server_info.put(server_paramater_message("application_name", ""));
+    server_info.put(server_paramater_message("client_encoding", "UTF8"));
+    server_info.put(server_paramater_message("server_encoding", "UTF8"));
+    server_info.put(server_paramater_message("server_version", VERSION));
+    server_info.put(server_paramater_message("DateStyle", "ISO, MDY"));
+
+    return server_info;
+}
 
 /// Handle admin client.
-pub async fn handle_admin(
-    stream: &mut OwnedWriteHalf,
+pub async fn handle_admin<T>(
+    stream: &mut T,
     mut query: BytesMut,
-    pool: ConnectionPool,
-) -> Result<(), Error> {
+    client_server_map: ClientServerMap,
+) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let code = query.get_u8() as char;
 
     if code != 'Q' {
@@ -29,52 +44,71 @@ pub async fn handle_admin(
 
     trace!("Admin query: {}", query);
 
-    if query.starts_with("SHOW STATS") {
-        trace!("SHOW STATS");
-        show_stats(stream, &pool).await
-    } else if query.starts_with("RELOAD") {
-        trace!("RELOAD");
-        reload(stream).await
-    } else if query.starts_with("SHOW CONFIG") {
-        trace!("SHOW CONFIG");
-        show_config(stream).await
-    } else if query.starts_with("SHOW DATABASES") {
-        trace!("SHOW DATABASES");
-        show_databases(stream, &pool).await
-    } else if query.starts_with("SHOW POOLS") {
-        trace!("SHOW POOLS");
-        show_pools(stream, &pool).await
-    } else if query.starts_with("SHOW LISTS") {
-        trace!("SHOW LISTS");
-        show_lists(stream, &pool).await
-    } else if query.starts_with("SHOW VERSION") {
-        trace!("SHOW VERSION");
-        show_version(stream).await
-    } else if query.starts_with("SET ") {
-        trace!("SET");
-        ignore_set(stream).await
-    } else {
-        error_response(stream, "Unsupported query against the admin database").await
+    let query_parts: Vec<&str> = query.trim_end_matches(';').split_whitespace().collect();
+
+    match query_parts[0] {
+        "RELOAD" => {
+            trace!("RELOAD");
+            reload(stream, client_server_map).await
+        }
+        "SET" => {
+            trace!("SET");
+            ignore_set(stream).await
+        }
+        "SHOW" => match query_parts[1] {
+            "CONFIG" => {
+                trace!("SHOW CONFIG");
+                show_config(stream).await
+            }
+            "DATABASES" => {
+                trace!("SHOW DATABASES");
+                show_databases(stream).await
+            }
+            "LISTS" => {
+                trace!("SHOW LISTS");
+                show_lists(stream).await
+            }
+            "POOLS" => {
+                trace!("SHOW POOLS");
+                show_pools(stream).await
+            }
+            "STATS" => {
+                trace!("SHOW STATS");
+                show_stats(stream).await
+            }
+            "VERSION" => {
+                trace!("SHOW VERSION");
+                show_version(stream).await
+            }
+            _ => error_response(stream, "Unsupported SHOW query against the admin database").await,
+        },
+        _ => error_response(stream, "Unsupported query against the admin database").await,
     }
 }
 
 /// Column-oriented statistics.
-async fn show_lists(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Result<(), Error> {
+async fn show_lists<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let stats = get_stats();
 
     let columns = vec![("list", DataType::Text), ("items", DataType::Int4)];
 
+    let mut users = 1;
+    let mut databases = 1;
+    for (_, pool) in get_all_pools() {
+        databases += pool.databases();
+        users += 1; // One user per pool
+    }
     let mut res = BytesMut::new();
     res.put(row_description(&columns));
     res.put(data_row(&vec![
         "databases".to_string(),
-        (pool.databases() + 1).to_string(), // see comment below
+        databases.to_string(),
     ]));
-    res.put(data_row(&vec!["users".to_string(), "1".to_string()]));
-    res.put(data_row(&vec![
-        "pools".to_string(),
-        (pool.databases() + 1).to_string(), // +1 for the pgbouncer admin db pool which isn't real
-    ])); // but admin tools that work with pgbouncer want this
+    res.put(data_row(&vec!["users".to_string(), users.to_string()]));
+    res.put(data_row(&vec!["pools".to_string(), databases.to_string()]));
     res.put(data_row(&vec![
         "free_clients".to_string(),
         stats
@@ -126,11 +160,14 @@ async fn show_lists(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Resul
 }
 
 /// Show PgCat version.
-async fn show_version(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
+async fn show_version<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut res = BytesMut::new();
 
     res.put(row_description(&vec![("version", DataType::Text)]));
-    res.put(data_row(&vec!["PgCat 0.1.0".to_string()]));
+    res.put(data_row(&vec![format!("PgCat {}", VERSION).to_string()]));
     res.put(command_complete("SHOW"));
 
     res.put_u8(b'Z');
@@ -141,16 +178,16 @@ async fn show_version(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
 }
 
 /// Show utilization of connection pools for each shard and replicas.
-async fn show_pools(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Result<(), Error> {
+async fn show_pools<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let stats = get_stats();
-    let config = {
-        let guard = get_config();
-        &*guard.clone()
-    };
 
     let columns = vec![
         ("database", DataType::Text),
         ("user", DataType::Text),
+        ("cl_idle", DataType::Numeric),
         ("cl_active", DataType::Numeric),
         ("cl_waiting", DataType::Numeric),
         ("cl_cancel_req", DataType::Numeric),
@@ -166,24 +203,26 @@ async fn show_pools(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Resul
 
     let mut res = BytesMut::new();
     res.put(row_description(&columns));
+    for (_, pool) in get_all_pools() {
+        let pool_config = &pool.settings;
+        for shard in 0..pool.shards() {
+            for server in 0..pool.servers(shard) {
+                let address = pool.address(shard, server);
+                let stats = match stats.get(&address.id) {
+                    Some(stats) => stats.clone(),
+                    None => HashMap::new(),
+                };
 
-    for shard in 0..pool.shards() {
-        for server in 0..pool.servers(shard) {
-            let address = pool.address(shard, server);
-            let stats = match stats.get(&address.id) {
-                Some(stats) => stats.clone(),
-                None => HashMap::new(),
-            };
+                let mut row = vec![address.name(), pool_config.user.username.clone()];
 
-            let mut row = vec![address.name(), config.user.name.clone()];
+                for column in &columns[2..columns.len() - 1] {
+                    let value = stats.get(column.0).unwrap_or(&0).to_string();
+                    row.push(value);
+                }
 
-            for column in &columns[2..columns.len() - 1] {
-                let value = stats.get(column.0).unwrap_or(&0).to_string();
-                row.push(value);
+                row.push(pool_config.pool_mode.to_string());
+                res.put(data_row(&row));
             }
-
-            row.push(config.general.pool_mode.to_string());
-            res.put(data_row(&row));
         }
     }
 
@@ -198,11 +237,10 @@ async fn show_pools(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Resul
 }
 
 /// Show shards and replicas.
-async fn show_databases(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Result<(), Error> {
-    let guard = get_config();
-    let config = &*guard.clone();
-    drop(guard);
-
+async fn show_databases<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     // Columns
     let columns = vec![
         ("name", DataType::Text),
@@ -224,31 +262,37 @@ async fn show_databases(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> R
 
     res.put(row_description(&columns));
 
-    for shard in 0..pool.shards() {
-        let database_name = &config.shards[&shard.to_string()].database;
+    for (_, pool) in get_all_pools() {
+        let pool_config = pool.settings.clone();
+        for shard in 0..pool.shards() {
+            let database_name = &pool.address(shard, 0).database;
+            for server in 0..pool.servers(shard) {
+                let address = pool.address(shard, server);
+                let pool_state = pool.pool_state(shard, server);
+                let banned = pool.is_banned(address, Some(address.role));
 
-        for server in 0..pool.servers(shard) {
-            let address = pool.address(shard, server);
-            let pool_state = pool.pool_state(shard, server);
-
-            res.put(data_row(&vec![
-                address.name(),                       // name
-                address.host.to_string(),             // host
-                address.port.to_string(),             // port
-                database_name.to_string(),            // database
-                config.user.name.to_string(),         // force_user
-                config.general.pool_size.to_string(), // pool_size
-                "0".to_string(),                      // min_pool_size
-                "0".to_string(),                      // reserve_pool
-                config.general.pool_mode.to_string(), // pool_mode
-                config.general.pool_size.to_string(), // max_connections
-                pool_state.connections.to_string(),   // current_connections
-                "0".to_string(),                      // paused
-                "0".to_string(),                      // disabled
-            ]));
+                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
+                    "0".to_string(),                        // paused
+                    match banned {
+                        // disabled
+                        true => "1".to_string(),
+                        false => "0".to_string(),
+                    },
+                ]));
+            }
         }
     }
-
     res.put(command_complete("SHOW"));
 
     // ReadyForQuery
@@ -261,22 +305,23 @@ async fn show_databases(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> R
 
 /// Ignore any SET commands the client sends.
 /// This is common initialization done by ORMs.
-async fn ignore_set(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
+async fn ignore_set<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     custom_protocol_response_ok(stream, "SET").await
 }
 
 /// Reload the configuration file without restarting the process.
-async fn reload(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
+async fn reload<T>(stream: &mut T, client_server_map: ClientServerMap) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     info!("Reloading config");
 
-    let config = get_config();
-    let path = config.path.clone().unwrap();
+    reload_config(client_server_map).await?;
 
-    parse(&path).await?;
-
-    let config = get_config();
-
-    config.show();
+    get_config().show();
 
     let mut res = BytesMut::new();
 
@@ -291,11 +336,12 @@ async fn reload(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
 }
 
 /// Shows current configuration.
-async fn show_config(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
-    let guard = get_config();
-    let config = &*guard.clone();
+async fn show_config<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
+    let config = &get_config();
     let config: HashMap<String, String> = config.into();
-    drop(guard);
 
     // Configs that cannot be changed without restarting.
     let immutables = ["host", "port", "connect_timeout"];
@@ -336,9 +382,13 @@ async fn show_config(stream: &mut OwnedWriteHalf) -> Result<(), Error> {
 }
 
 /// Show shard and replicas statistics.
-async fn show_stats(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Result<(), Error> {
+async fn show_stats<T>(stream: &mut T) -> Result<(), Error>
+where
+    T: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let columns = vec![
         ("database", DataType::Text),
+        ("user", DataType::Text),
         ("total_xact_count", DataType::Numeric),
         ("total_query_count", DataType::Numeric),
         ("total_received", DataType::Numeric),
@@ -359,21 +409,24 @@ async fn show_stats(stream: &mut OwnedWriteHalf, pool: &ConnectionPool) -> Resul
     let mut res = BytesMut::new();
     res.put(row_description(&columns));
 
-    for shard in 0..pool.shards() {
-        for server in 0..pool.servers(shard) {
-            let address = pool.address(shard, server);
-            let stats = match stats.get(&address.id) {
-                Some(stats) => stats.clone(),
-                None => HashMap::new(),
-            };
+    for ((_db_name, username), pool) in get_all_pools() {
+        for shard in 0..pool.shards() {
+            for server in 0..pool.servers(shard) {
+                let address = pool.address(shard, server);
+                let stats = match stats.get(&address.id) {
+                    Some(stats) => stats.clone(),
+                    None => HashMap::new(),
+                };
 
-            let mut row = vec![address.name()];
+                let mut row = vec![address.name()];
+                row.push(username.clone());
 
-            for column in &columns[1..] {
-                row.push(stats.get(column.0).unwrap_or(&0).to_string());
+                for column in &columns[2..] {
+                    row.push(stats.get(column.0).unwrap_or(&0).to_string());
+                }
+
+                res.put(data_row(&row));
             }
-
-            res.put(data_row(&row));
         }
     }
 

src/config.rs

@@ -1,21 +1,27 @@
 /// Parse the configuration file.
-use arc_swap::{ArcSwap, Guard};
+use arc_swap::ArcSwap;
 use log::{error, info};
 use once_cell::sync::Lazy;
-use serde_derive::Deserialize;
+use serde_derive::{Deserialize, Serialize};
 use std::collections::{HashMap, HashSet};
+use std::hash::Hash;
+use std::path::Path;
 use std::sync::Arc;
 use tokio::fs::File;
 use tokio::io::AsyncReadExt;
 use toml;
 
 use crate::errors::Error;
+use crate::tls::{load_certs, load_keys};
+use crate::{ClientServerMap, ConnectionPool};
+
+pub const VERSION: &str = env!("CARGO_PKG_VERSION");
 
 /// Globally available configuration.
 static CONFIG: Lazy<ArcSwap<Config>> = Lazy::new(|| ArcSwap::from_pointee(Config::default()));
 
 /// Server role: primary or replica.
-#[derive(Clone, PartialEq, Deserialize, Hash, std::cmp::Eq, Debug, Copy)]
+#[derive(Clone, PartialEq, Serialize, Deserialize, Hash, std::cmp::Eq, Debug, Copy)]
 pub enum Role {
     Primary,
     Replica,
@@ -51,12 +57,35 @@ impl PartialEq<Role> for Option<Role> {
 /// Address identifying a PostgreSQL server uniquely.
 #[derive(Clone, PartialEq, Hash, std::cmp::Eq, Debug)]
 pub struct Address {
+    /// Unique ID per addressable Postgres server.
     pub id: usize,
+
+    /// Server host.
     pub host: String,
-    pub port: String,
+
+    /// Server port.
+    pub port: u16,
+
+    /// Shard number of this Postgres server.
     pub shard: usize,
+
+    /// The name of the Postgres database.
+    pub database: String,
+
+    /// Server role: replica, primary.
     pub role: Role,
+
+    /// If it's a replica, number it for reference and failover.
     pub replica_number: usize,
+
+    /// Position of the server in the pool for failover.
+    pub address_index: usize,
+
+    /// The name of the user configured to use this pool.
+    pub username: String,
+
+    /// The name of this pool (i.e. database name visible to the client).
+    pub pool_name: String,
 }
 
 impl Default for Address {
@@ -64,10 +93,14 @@ impl Default for Address {
         Address {
             id: 0,
             host: String::from("127.0.0.1"),
-            port: String::from("5432"),
+            port: 5432,
             shard: 0,
+            address_index: 0,
             replica_number: 0,
+            database: String::from("database"),
             role: Role::Replica,
+            username: String::from("username"),
+            pool_name: String::from("pool_name"),
         }
     }
 }
@@ -76,39 +109,53 @@ impl Address {
     /// Address name (aka database) used in `SHOW STATS`, `SHOW DATABASES`, and `SHOW POOLS`.
     pub fn name(&self) -> String {
         match self.role {
-            Role::Primary => format!("shard_{}_primary", self.shard),
+            Role::Primary => format!("{}_shard_{}_primary", self.pool_name, self.shard),
 
-            Role::Replica => format!("shard_{}_replica_{}", self.shard, self.replica_number),
+            Role::Replica => format!(
+                "{}_shard_{}_replica_{}",
+                self.pool_name, self.shard, self.replica_number
+            ),
         }
     }
 }
 
 /// PostgreSQL user.
-#[derive(Clone, PartialEq, Hash, std::cmp::Eq, Deserialize, Debug)]
+#[derive(Clone, PartialEq, Hash, std::cmp::Eq, Serialize, Deserialize, Debug)]
 pub struct User {
-    pub name: String,
+    pub username: String,
     pub password: String,
+    pub pool_size: u32,
+    pub statement_timeout: u64,
 }
 
 impl Default for User {
     fn default() -> User {
         User {
-            name: String::from("postgres"),
+            username: String::from("postgres"),
             password: String::new(),
+            pool_size: 15,
+            statement_timeout: 0,
         }
     }
 }
 
 /// General configuration.
-#[derive(Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct General {
     pub host: String,
     pub port: i16,
-    pub pool_size: u32,
-    pub pool_mode: String,
+    pub enable_prometheus_exporter: Option<bool>,
+    pub prometheus_exporter_port: i16,
     pub connect_timeout: u64,
     pub healthcheck_timeout: u64,
+    pub shutdown_timeout: u64,
+    pub healthcheck_delay: u64,
     pub ban_time: i64,
+    pub autoreload: bool,
+    pub tls_certificate: Option<String>,
+    pub tls_private_key: Option<String>,
+    pub admin_username: String,
+    pub admin_password: String,
 }
 
 impl Default for General {
@@ -116,20 +163,52 @@ impl Default for General {
         General {
             host: String::from("localhost"),
             port: 5432,
-            pool_size: 15,
-            pool_mode: String::from("transaction"),
+            enable_prometheus_exporter: Some(false),
+            prometheus_exporter_port: 9930,
             connect_timeout: 5000,
             healthcheck_timeout: 1000,
+            shutdown_timeout: 60000,
+            healthcheck_delay: 30000,
             ban_time: 60,
+            autoreload: false,
+            tls_certificate: None,
+            tls_private_key: None,
+            admin_username: String::from("admin"),
+            admin_password: String::from("admin"),
+        }
+    }
+}
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+pub struct Pool {
+    pub pool_mode: String,
+    pub default_role: String,
+    pub query_parser_enabled: bool,
+    pub primary_reads_enabled: bool,
+    pub sharding_function: String,
+    pub sharding_key: Option<String>,
+    pub shards: HashMap<String, Shard>,
+    pub users: HashMap<String, User>,
+}
+impl Default for Pool {
+    fn default() -> Pool {
+        Pool {
+            pool_mode: String::from("transaction"),
+            shards: HashMap::from([(String::from("1"), Shard::default())]),
+            users: HashMap::default(),
+            default_role: String::from("any"),
+            query_parser_enabled: false,
+            primary_reads_enabled: true,
+            sharding_function: "pg_bigint_hash".to_string(),
+            sharding_key: None,
         }
     }
 }
 
 /// Shard configuration.
-#[derive(Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct Shard {
-    pub servers: Vec<(String, u16, String)>,
     pub database: String,
+    pub servers: Vec<(String, u16, String)>,
 }
 
 impl Default for Shard {
@@ -141,60 +220,91 @@ impl Default for Shard {
     }
 }
 
-/// Query Router configuration.
-#[derive(Deserialize, Debug, Clone)]
-pub struct QueryRouter {
-    pub default_role: String,
-    pub query_parser_enabled: bool,
-    pub primary_reads_enabled: bool,
-    pub sharding_function: String,
-}
-
-impl Default for QueryRouter {
-    fn default() -> QueryRouter {
-        QueryRouter {
-            default_role: String::from("any"),
-            query_parser_enabled: false,
-            primary_reads_enabled: true,
-            sharding_function: "pg_bigint_hash".to_string(),
-        }
-    }
+fn default_path() -> String {
+    String::from("pgcat.toml")
 }
 
 /// Configuration wrapper.
-#[derive(Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct Config {
-    pub path: Option<String>,
+    // Serializer maintains the order of fields in the struct
+    // so we should always put simple fields before nested fields
+    // in all serializable structs to avoid ValueAfterTable errors
+    // These errors occur when the toml serializer is about to produce
+    // ambigous toml structure like the one below
+    // [main]
+    // field1_under_main = 1
+    // field2_under_main = 2
+    // [main.subconf]
+    // field1_under_subconf = 1
+    // field3_under_main = 3 # This field will be interpreted as being under subconf and not under main
+    #[serde(default = "default_path")]
+    pub path: String,
+
     pub general: General,
-    pub user: User,
-    pub shards: HashMap<String, Shard>,
-    pub query_router: QueryRouter,
+    pub pools: HashMap<String, Pool>,
 }
 
 impl Default for Config {
     fn default() -> Config {
         Config {
-            path: Some(String::from("pgcat.toml")),
+            path: String::from("pgcat.toml"),
             general: General::default(),
-            user: User::default(),
-            shards: HashMap::from([(String::from("1"), Shard::default())]),
-            query_router: QueryRouter::default(),
+            pools: HashMap::default(),
         }
     }
 }
 
 impl From<&Config> for std::collections::HashMap<String, String> {
     fn from(config: &Config) -> HashMap<String, String> {
-        HashMap::from([
+        let mut r: Vec<(String, String)> = config
+            .pools
+            .iter()
+            .flat_map(|(pool_name, pool)| {
+                [
+                    (
+                        format!("pools.{}.pool_mode", pool_name),
+                        pool.pool_mode.clone(),
+                    ),
+                    (
+                        format!("pools.{}.primary_reads_enabled", pool_name),
+                        pool.primary_reads_enabled.to_string(),
+                    ),
+                    (
+                        format!("pools.{}.query_parser_enabled", pool_name),
+                        pool.query_parser_enabled.to_string(),
+                    ),
+                    (
+                        format!("pools.{}.default_role", pool_name),
+                        pool.default_role.clone(),
+                    ),
+                    (
+                        format!("pools.{}.sharding_function", pool_name),
+                        pool.sharding_function.clone(),
+                    ),
+                    (
+                        format!("pools.{:?}.shard_count", pool_name),
+                        pool.shards.len().to_string(),
+                    ),
+                    (
+                        format!("pools.{:?}.users", pool_name),
+                        pool.users
+                            .iter()
+                            .map(|(_username, user)| &user.username)
+                            .cloned()
+                            .collect::<Vec<String>>()
+                            .join(", "),
+                    ),
+                ]
+            })
+            .collect();
+
+        let mut static_settings = vec![
             ("host".to_string(), config.general.host.to_string()),
             ("port".to_string(), config.general.port.to_string()),
             (
-                "pool_size".to_string(),
-                config.general.pool_size.to_string(),
-            ),
-            (
-                "pool_mode".to_string(),
-                config.general.pool_mode.to_string(),
+                "prometheus_exporter_port".to_string(),
+                config.general.prometheus_exporter_port.to_string(),
             ),
             (
                 "connect_timeout".to_string(),
@@ -204,48 +314,107 @@ impl From<&Config> for std::collections::HashMap<String, String> {
                 "healthcheck_timeout".to_string(),
                 config.general.healthcheck_timeout.to_string(),
             ),
+            (
+                "shutdown_timeout".to_string(),
+                config.general.shutdown_timeout.to_string(),
+            ),
+            (
+                "healthcheck_delay".to_string(),
+                config.general.healthcheck_delay.to_string(),
+            ),
             ("ban_time".to_string(), config.general.ban_time.to_string()),
-            (
-                "default_role".to_string(),
-                config.query_router.default_role.to_string(),
-            ),
-            (
-                "query_parser_enabled".to_string(),
-                config.query_router.query_parser_enabled.to_string(),
-            ),
-            (
-                "primary_reads_enabled".to_string(),
-                config.query_router.primary_reads_enabled.to_string(),
-            ),
-            (
-                "sharding_function".to_string(),
-                config.query_router.sharding_function.to_string(),
-            ),
-        ])
+        ];
+
+        r.append(&mut static_settings);
+        return r.iter().cloned().collect();
     }
 }
 
 impl Config {
     /// Print current configuration.
     pub fn show(&self) {
-        info!("Pool size: {}", self.general.pool_size);
-        info!("Pool mode: {}", self.general.pool_mode);
         info!("Ban time: {}s", self.general.ban_time);
         info!(
             "Healthcheck timeout: {}ms",
             self.general.healthcheck_timeout
         );
         info!("Connection timeout: {}ms", self.general.connect_timeout);
-        info!("Sharding function: {}", self.query_router.sharding_function);
-        info!("Number of shards: {}", self.shards.len());
+        info!("Shutdown timeout: {}ms", self.general.shutdown_timeout);
+        info!("Healthcheck delay: {}ms", self.general.healthcheck_delay);
+        match self.general.tls_certificate.clone() {
+            Some(tls_certificate) => {
+                info!("TLS certificate: {}", tls_certificate);
+
+                match self.general.tls_private_key.clone() {
+                    Some(tls_private_key) => {
+                        info!("TLS private key: {}", tls_private_key);
+                        info!("TLS support is enabled");
+                    }
+
+                    None => (),
+                }
+            }
+
+            None => {
+                info!("TLS support is disabled");
+            }
+        };
+
+        for (pool_name, pool_config) in &self.pools {
+            // TODO: Make this output prettier (maybe a table?)
+            info!(
+                "[pool: {}] Maximum user connections: {}",
+                pool_name,
+                pool_config
+                    .users
+                    .iter()
+                    .map(|(_, user_cfg)| user_cfg.pool_size)
+                    .sum::<u32>()
+                    .to_string()
+            );
+            info!("[pool: {}] Pool mode: {}", pool_name, pool_config.pool_mode);
+            info!(
+                "[pool: {}] Sharding function: {}",
+                pool_name, pool_config.sharding_function
+            );
+            info!(
+                "[pool: {}] Primary reads: {}",
+                pool_name, pool_config.primary_reads_enabled
+            );
+            info!(
+                "[pool: {}] Query router: {}",
+                pool_name, pool_config.query_parser_enabled
+            );
+            info!(
+                "[pool: {}] Number of shards: {}",
+                pool_name,
+                pool_config.shards.len()
+            );
+            info!(
+                "[pool: {}] Number of users: {}",
+                pool_name,
+                pool_config.users.len()
+            );
+
+            for user in &pool_config.users {
+                info!(
+                    "[pool: {}][user: {}] Pool size: {}",
+                    pool_name, user.1.username, user.1.pool_size,
+                );
+                info!(
+                    "[pool: {}][user: {}] Statement timeout: {}",
+                    pool_name, user.1.username, user.1.statement_timeout
+                )
+            }
+        }
     }
 }
 
 /// Get a read-only instance of the configuration
 /// from anywhere in the app.
 /// ArcSwap makes this cheap and quick.
-pub fn get_config() -> Guard<Arc<Config>> {
-    CONFIG.load()
+pub fn get_config() -> Config {
+    (*(*CONFIG.load())).clone()
 }
 
 /// Parse the configuration file located at the path.
@@ -275,89 +444,134 @@ pub async fn parse(path: &str) -> Result<(), Error> {
         }
     };
 
-    match config.query_router.sharding_function.as_ref() {
-        "pg_bigint_hash" => (),
-        "sha1" => (),
-        _ => {
-            error!(
-                "Supported sharding functions are: 'pg_bigint_hash', 'sha1', got: '{}'",
-                config.query_router.sharding_function
-            );
-            return Err(Error::BadConfig);
+    // Validate TLS!
+    match config.general.tls_certificate.clone() {
+        Some(tls_certificate) => {
+            match load_certs(&Path::new(&tls_certificate)) {
+                Ok(_) => {
+                    // Cert is okay, but what about the private key?
+                    match config.general.tls_private_key.clone() {
+                        Some(tls_private_key) => match load_keys(&Path::new(&tls_private_key)) {
+                            Ok(_) => (),
+                            Err(err) => {
+                                error!("tls_private_key is incorrectly configured: {:?}", err);
+                                return Err(Error::BadConfig);
+                            }
+                        },
+
+                        None => {
+                            error!("tls_certificate is set, but the tls_private_key is not");
+                            return Err(Error::BadConfig);
+                        }
+                    };
+                }
+
+                Err(err) => {
+                    error!("tls_certificate is incorrectly configured: {:?}", err);
+                    return Err(Error::BadConfig);
+                }
+            }
         }
+        None => (),
     };
 
-    // Quick config sanity check.
-    for shard in &config.shards {
-        // We use addresses as unique identifiers,
-        // let's make sure they are unique in the config as well.
-        let mut dup_check = HashSet::new();
-        let mut primary_count = 0;
-
-        match shard.0.parse::<usize>() {
-            Ok(_) => (),
-            Err(_) => {
+    for (pool_name, pool) in &config.pools {
+        match pool.sharding_function.as_ref() {
+            "pg_bigint_hash" => (),
+            "sha1" => (),
+            _ => {
                 error!(
-                    "Shard '{}' is not a valid number, shards must be numbered starting at 0",
-                    shard.0
+                    "Supported sharding functions are: 'pg_bigint_hash', 'sha1', got: '{}' in pool {} settings",
+                    pool.sharding_function,
+                    pool_name
                 );
                 return Err(Error::BadConfig);
             }
         };
 
-        if shard.1.servers.len() == 0 {
-            error!("Shard {} has no servers configured", shard.0);
-            return Err(Error::BadConfig);
-        }
+        match pool.default_role.as_ref() {
+            "any" => (),
+            "primary" => (),
+            "replica" => (),
+            other => {
+                error!(
+                    "Query router default_role must be 'primary', 'replica', or 'any', got: '{}'",
+                    other
+                );
+                return Err(Error::BadConfig);
+            }
+        };
 
-        for server in &shard.1.servers {
-            dup_check.insert(server);
+        match pool.pool_mode.as_ref() {
+            "transaction" => (),
+            "session" => (),
+            other => {
+                error!(
+                    "pool_mode can be 'session' or 'transaction', got: '{}'",
+                    other
+                );
+                return Err(Error::BadConfig);
+            }
+        };
 
-            // Check that we define only zero or one primary.
-            match server.2.as_ref() {
-                "primary" => primary_count += 1,
-                _ => (),
-            };
+        for shard in &pool.shards {
+            // We use addresses as unique identifiers,
+            // let's make sure they are unique in the config as well.
+            let mut dup_check = HashSet::new();
+            let mut primary_count = 0;
 
-            // Check role spelling.
-            match server.2.as_ref() {
-                "primary" => (),
-                "replica" => (),
-                _ => {
+            match shard.0.parse::<usize>() {
+                Ok(_) => (),
+                Err(_) => {
                     error!(
-                        "Shard {} server role must be either 'primary' or 'replica', got: '{}'",
-                        shard.0, server.2
+                        "Shard '{}' is not a valid number, shards must be numbered starting at 0",
+                        shard.0
                     );
                     return Err(Error::BadConfig);
                 }
             };
-        }
 
-        if primary_count > 1 {
-            error!("Shard {} has more than on primary configured", &shard.0);
-            return Err(Error::BadConfig);
-        }
+            if shard.1.servers.len() == 0 {
+                error!("Shard {} has no servers configured", shard.0);
+                return Err(Error::BadConfig);
+            }
 
-        if dup_check.len() != shard.1.servers.len() {
-            error!("Shard {} contains duplicate server configs", &shard.0);
-            return Err(Error::BadConfig);
+            for server in &shard.1.servers {
+                dup_check.insert(server);
+
+                // Check that we define only zero or one primary.
+                match server.2.as_ref() {
+                    "primary" => primary_count += 1,
+                    _ => (),
+                };
+
+                // Check role spelling.
+                match server.2.as_ref() {
+                    "primary" => (),
+                    "replica" => (),
+                    _ => {
+                        error!(
+                            "Shard {} server role must be either 'primary' or 'replica', got: '{}'",
+                            shard.0, server.2
+                        );
+                        return Err(Error::BadConfig);
+                    }
+                };
+            }
+
+            if primary_count > 1 {
+                error!("Shard {} has more than on primary configured", &shard.0);
+                return Err(Error::BadConfig);
+            }
+
+            if dup_check.len() != shard.1.servers.len() {
+                error!("Shard {} contains duplicate server configs", &shard.0);
+                return Err(Error::BadConfig);
+            }
         }
     }
 
-    match config.query_router.default_role.as_ref() {
-        "any" => (),
-        "primary" => (),
-        "replica" => (),
-        other => {
-            error!(
-                "Query router default_role must be 'primary', 'replica', or 'any', got: '{}'",
-                other
-            );
-            return Err(Error::BadConfig);
-        }
-    };
-
-    config.path = Some(path.to_string());
+    config.path = path.to_string();
 
     // Update the configuration globally.
     CONFIG.store(Arc::new(config.clone()));
@@ -365,6 +579,28 @@ pub async fn parse(path: &str) -> Result<(), Error> {
     Ok(())
 }
 
+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) => {
+            error!("Config reload error: {:?}", err);
+            return Err(Error::BadConfig);
+        }
+    };
+    let new_config = get_config();
+
+    if old_config.pools != new_config.pools {
+        info!("Pool configuration changed, re-creating server pools");
+        ConnectionPool::from_config(client_server_map).await?;
+        Ok(true)
+    } else if old_config != new_config {
+        Ok(true)
+    } else {
+        Ok(false)
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -372,11 +608,67 @@ mod test {
     #[tokio::test]
     async fn test_config() {
         parse("pgcat.toml").await.unwrap();
-        assert_eq!(get_config().general.pool_size, 15);
-        assert_eq!(get_config().shards.len(), 3);
-        assert_eq!(get_config().shards["1"].servers[0].0, "127.0.0.1");
-        assert_eq!(get_config().shards["0"].servers[0].2, "primary");
-        assert_eq!(get_config().query_router.default_role, "any");
-        assert_eq!(get_config().path, Some("pgcat.toml".to_string()));
+
+        assert_eq!(get_config().path, "pgcat.toml".to_string());
+
+        assert_eq!(get_config().general.ban_time, 60);
+        assert_eq!(get_config().pools.len(), 2);
+        assert_eq!(get_config().pools["sharded_db"].shards.len(), 3);
+        assert_eq!(get_config().pools["simple_db"].shards.len(), 1);
+        assert_eq!(get_config().pools["sharded_db"].users.len(), 2);
+        assert_eq!(get_config().pools["simple_db"].users.len(), 1);
+
+        assert_eq!(
+            get_config().pools["sharded_db"].shards["0"].servers[0].0,
+            "127.0.0.1"
+        );
+        assert_eq!(
+            get_config().pools["sharded_db"].shards["1"].servers[0].2,
+            "primary"
+        );
+        assert_eq!(
+            get_config().pools["sharded_db"].shards["1"].database,
+            "shard1"
+        );
+        assert_eq!(
+            get_config().pools["sharded_db"].users["0"].username,
+            "sharding_user"
+        );
+        assert_eq!(
+            get_config().pools["sharded_db"].users["1"].password,
+            "other_user"
+        );
+        assert_eq!(get_config().pools["sharded_db"].users["1"].pool_size, 21);
+        assert_eq!(get_config().pools["sharded_db"].default_role, "any");
+
+        assert_eq!(
+            get_config().pools["simple_db"].shards["0"].servers[0].0,
+            "127.0.0.1"
+        );
+        assert_eq!(
+            get_config().pools["simple_db"].shards["0"].servers[0].1,
+            5432
+        );
+        assert_eq!(
+            get_config().pools["simple_db"].shards["0"].database,
+            "some_db"
+        );
+        assert_eq!(get_config().pools["simple_db"].default_role, "primary");
+
+        assert_eq!(
+            get_config().pools["simple_db"].users["0"].username,
+            "simple_user"
+        );
+        assert_eq!(
+            get_config().pools["simple_db"].users["0"].password,
+            "simple_user"
+        );
+        assert_eq!(get_config().pools["simple_db"].users["0"].pool_size, 5);
+    }
+
+    #[tokio::test]
+    async fn test_serialize_configs() {
+        parse("pgcat.toml").await.unwrap();
+        print!("{}", toml::to_string(&get_config()).unwrap());
     }
 }

src/errors.rs

@@ -10,4 +10,7 @@ pub enum Error {
     BadConfig,
     AllServersDown,
     ClientError,
+    TlsError,
+    StatementTimeout,
+    ShuttingDown,
 }

src/main.rs

@@ -1,4 +1,4 @@
-// Copyright (c) 2022 Lev Kokotov <lev@levthe.dev>
+// Copyright (c) 2022 Lev Kokotov <hi@levthe.dev>
 
 // Permission is hereby granted, free of charge, to any person obtaining
 // a copy of this software and associated documentation files (the
@@ -24,27 +24,32 @@ extern crate async_trait;
 extern crate bb8;
 extern crate bytes;
 extern crate env_logger;
+extern crate exitcode;
 extern crate log;
 extern crate md5;
 extern crate num_cpus;
 extern crate once_cell;
+extern crate rustls_pemfile;
 extern crate serde;
 extern crate serde_derive;
 extern crate sqlparser;
 extern crate tokio;
+extern crate tokio_rustls;
 extern crate toml;
 
-use log::{error, info};
+use log::{debug, error, info};
 use parking_lot::Mutex;
 use tokio::net::TcpListener;
 use tokio::{
-    signal,
     signal::unix::{signal as unix_signal, SignalKind},
     sync::mpsc,
 };
 
 use std::collections::HashMap;
+use std::net::SocketAddr;
+use std::str::FromStr;
 use std::sync::Arc;
+use tokio::sync::broadcast;
 
 mod admin;
 mod client;
@@ -53,24 +58,29 @@ mod constants;
 mod errors;
 mod messages;
 mod pool;
+mod prometheus;
 mod query_router;
 mod scram;
 mod server;
 mod sharding;
 mod stats;
+mod tls;
 
-use config::get_config;
-use pool::{ClientServerMap, ConnectionPool};
-use stats::{Collector, Reporter};
+use crate::config::{get_config, reload_config, VERSION};
+use crate::errors::Error;
+use crate::pool::{ClientServerMap, ConnectionPool};
+use crate::prometheus::start_metric_server;
+use crate::stats::{Collector, Reporter, REPORTER};
 
 #[tokio::main(worker_threads = 4)]
 async fn main() {
-    env_logger::init();
-    info!("Welcome to PgCat! Meow.");
+    env_logger::builder().format_timestamp_micros().init();
+
+    info!("Welcome to PgCat! Meow. (Version {})", VERSION);
 
     if !query_router::QueryRouter::setup() {
         error!("Could not setup query router");
-        return;
+        std::process::exit(exitcode::CONFIG);
     }
 
     let args = std::env::args().collect::<Vec<String>>();
@@ -85,18 +95,36 @@ async fn main() {
         Ok(_) => (),
         Err(err) => {
             error!("Config parse error: {:?}", err);
-            return;
+            std::process::exit(exitcode::CONFIG);
         }
     };
 
     let config = get_config();
+
+    if let Some(true) = config.general.enable_prometheus_exporter {
+        let http_addr_str = format!(
+            "{}:{}",
+            config.general.host, config.general.prometheus_exporter_port
+        );
+        let http_addr = match SocketAddr::from_str(&http_addr_str) {
+            Ok(addr) => addr,
+            Err(err) => {
+                error!("Invalid http address: {}", err);
+                std::process::exit(exitcode::CONFIG);
+            }
+        };
+        tokio::task::spawn(async move {
+            start_metric_server(http_addr).await;
+        });
+    }
+
     let addr = format!("{}:{}", config.general.host, config.general.port);
 
     let listener = match TcpListener::bind(&addr).await {
         Ok(sock) => sock,
         Err(err) => {
             error!("Listener socket error: {:?}", err);
-            return;
+            std::process::exit(exitcode::CONFIG);
         }
     };
 
@@ -108,108 +136,168 @@ async fn main() {
     let client_server_map: ClientServerMap = Arc::new(Mutex::new(HashMap::new()));
 
     // Statistics reporting.
-    let (tx, rx) = mpsc::channel(100);
+    let (stats_tx, stats_rx) = mpsc::channel(100_000);
+    REPORTER.store(Arc::new(Reporter::new(stats_tx.clone())));
 
     // Connection pool that allows to query all shards and replicas.
-    let mut pool =
-        ConnectionPool::from_config(client_server_map.clone(), Reporter::new(tx.clone())).await;
-
-    // Statistics collector task.
-    let collector_tx = tx.clone();
-    let addresses = pool.databases();
-    tokio::task::spawn(async move {
-        let mut stats_collector = Collector::new(rx, collector_tx);
-        stats_collector.collect(addresses).await;
-    });
-
-    // Connect to all servers and validate their versions.
-    let server_info = match pool.validate().await {
-        Ok(info) => info,
+    match ConnectionPool::from_config(client_server_map.clone()).await {
+        Ok(_) => (),
         Err(err) => {
-            error!("Could not validate connection pool: {:?}", err);
-            return;
+            error!("Pool error: {:?}", err);
+            std::process::exit(exitcode::CONFIG);
         }
     };
 
+    tokio::task::spawn(async move {
+        let mut stats_collector = Collector::new(stats_rx, stats_tx.clone());
+        stats_collector.collect().await;
+    });
+
+    info!("Config autoreloader: {}", config.general.autoreload);
+
+    let mut autoreload_interval = tokio::time::interval(tokio::time::Duration::from_millis(15_000));
+    let autoreload_client_server_map = client_server_map.clone();
+    tokio::task::spawn(async move {
+        loop {
+            autoreload_interval.tick().await;
+            if config.general.autoreload {
+                info!("Automatically reloading config");
+
+                match reload_config(autoreload_client_server_map.clone()).await {
+                    Ok(changed) => {
+                        if changed {
+                            get_config().show()
+                        }
+                    }
+                    Err(_) => (),
+                };
+            }
+        }
+    });
+
+    let mut term_signal = unix_signal(SignalKind::terminate()).unwrap();
+    let mut interrupt_signal = unix_signal(SignalKind::interrupt()).unwrap();
+    let mut sighup_signal = unix_signal(SignalKind::hangup()).unwrap();
+    let (shutdown_tx, _) = broadcast::channel::<()>(1);
+    let (drain_tx, mut drain_rx) = mpsc::channel::<i32>(2048);
+    let (exit_tx, mut exit_rx) = mpsc::channel::<()>(1);
+
     info!("Waiting for clients");
 
-    // Client connection loop.
-    tokio::task::spawn(async move {
-        loop {
-            let pool = pool.clone();
-            let client_server_map = client_server_map.clone();
-            let server_info = server_info.clone();
-            let reporter = Reporter::new(tx.clone());
+    let mut admin_only = false;
+    let mut total_clients = 0;
 
-            let (socket, addr) = match listener.accept().await {
-                Ok((socket, addr)) => (socket, addr),
-                Err(err) => {
-                    error!("{:?}", err);
-                    continue;
-                }
-            };
+    loop {
+        tokio::select! {
+            // Reload config:
+            // kill -SIGHUP $(pgrep pgcat)
+            _ = sighup_signal.recv() => {
+                info!("Reloading config");
 
-            // Handle client.
-            tokio::task::spawn(async move {
-                let start = chrono::offset::Utc::now().naive_utc();
-                match client::Client::startup(socket, client_server_map, server_info, reporter)
-                    .await
-                {
-                    Ok(mut client) => {
-                        info!("Client {:?} connected", addr);
-                        match client.handle(pool).await {
-                            Ok(()) => {
-                                let duration = chrono::offset::Utc::now().naive_utc() - start;
+                match reload_config(client_server_map.clone()).await {
+                    Ok(_) => (),
+                    Err(_) => (),
+                };
 
-                                info!(
-                                    "Client {:?} disconnected, session duration: {}",
-                                    addr,
-                                    format_duration(&duration)
-                                );
-                            }
+                get_config().show();
+            },
 
-                            Err(err) => {
-                                error!("Client disconnected with error: {:?}", err);
-                                client.release();
-                            }
-                        }
-                    }
+            // Initiate graceful shutdown sequence on sig int
+            _ = interrupt_signal.recv() => {
+                info!("Got SIGINT, waiting for client connection drain now");
+                admin_only = true;
 
+                // Broadcast that client tasks need to finish
+                let _ = shutdown_tx.send(());
+                let exit_tx = exit_tx.clone();
+                let _ = drain_tx.send(0).await;
+
+                tokio::task::spawn(async move {
+                    let mut interval = tokio::time::interval(tokio::time::Duration::from_millis(config.general.shutdown_timeout));
+
+                    // First tick fires immediately.
+                    interval.tick().await;
+
+                    // Second one in the interval time.
+                    interval.tick().await;
+
+                    // We're done waiting.
+                    error!("Graceful shutdown timed out. {} active clients being closed", total_clients);
+
+                    let _ = exit_tx.send(()).await;
+                });
+            },
+
+            _ = term_signal.recv() => {
+                info!("Got SIGTERM, closing with {} clients active", total_clients);
+                break;
+            },
+
+            new_client = listener.accept() => {
+                let (socket, addr) = match new_client {
+                    Ok((socket, addr)) => (socket, addr),
                     Err(err) => {
-                        error!("Client failed to login: {:?}", err);
+                        error!("{:?}", err);
+                        continue;
                     }
                 };
-            });
-        }
-    });
 
-    // Reload config:
-    // kill -SIGHUP $(pgrep pgcat)
-    tokio::task::spawn(async move {
-        let mut stream = unix_signal(SignalKind::hangup()).unwrap();
+                let shutdown_rx = shutdown_tx.subscribe();
+                let drain_tx = drain_tx.clone();
+                let client_server_map = client_server_map.clone();
 
-        loop {
-            stream.recv().await;
-            info!("Reloading config");
-            match config::parse("pgcat.toml").await {
-                Ok(_) => {
-                    get_config().show();
+                tokio::task::spawn(async move {
+                    let start = chrono::offset::Utc::now().naive_utc();
+
+                    match client::client_entrypoint(
+                        socket,
+                        client_server_map,
+                        shutdown_rx,
+                        drain_tx,
+                        admin_only,
+                    )
+                    .await
+                    {
+                        Ok(()) => {
+
+                            let duration = chrono::offset::Utc::now().naive_utc() - start;
+
+                            info!(
+                                "Client {:?} disconnected, session duration: {}",
+                                addr,
+                                format_duration(&duration)
+                            );
+                        }
+
+                        Err(err) => {
+                            match err {
+                                // Don't count the clients we rejected.
+                                Error::ShuttingDown => (),
+                                _ => {
+                                    // drain_tx.send(-1).await.unwrap();
+                                }
+                            }
+
+                            debug!("Client disconnected with error {:?}", err);
+                        }
+                    };
+                });
+            }
+
+            _ = exit_rx.recv() => {
+                break;
+            }
+
+            client_ping = drain_rx.recv() => {
+                let client_ping = client_ping.unwrap();
+                total_clients += client_ping;
+
+                if total_clients == 0 && admin_only {
+                    let _ = exit_tx.send(()).await;
                 }
-                Err(err) => {
-                    error!("{:?}", err);
-                    return;
-                }
-            };
+            }
         }
-    });
-
-    // Exit on Ctrl-C (SIGINT) and SIGTERM.
-    let mut term_signal = unix_signal(SignalKind::terminate()).unwrap();
-
-    tokio::select! {
-        _ = signal::ctrl_c() => (),
-        _ = term_signal.recv() => (),
-    };
+    }
 
     info!("Shutting down...");
 }
@@ -220,34 +308,18 @@ async fn main() {
 ///
 /// * `duration` - A duration of time
 fn format_duration(duration: &chrono::Duration) -> String {
-    let seconds = {
-        let seconds = duration.num_seconds() % 60;
-        if seconds < 10 {
-            format!("0{}", seconds)
-        } else {
-            format!("{}", seconds)
-        }
-    };
+    let milliseconds = format!("{:0>3}", duration.num_milliseconds() % 1000);
 
-    let minutes = {
-        let minutes = duration.num_minutes() % 60;
-        if minutes < 10 {
-            format!("0{}", minutes)
-        } else {
-            format!("{}", minutes)
-        }
-    };
+    let seconds = format!("{:0>2}", duration.num_seconds() % 60);
 
-    let hours = {
-        let hours = duration.num_hours() % 24;
-        if hours < 10 {
-            format!("0{}", hours)
-        } else {
-            format!("{}", hours)
-        }
-    };
+    let minutes = format!("{:0>2}", duration.num_minutes() % 60);
+
+    let hours = format!("{:0>2}", duration.num_hours() % 24);
 
     let days = duration.num_days().to_string();
 
-    format!("{}d {}:{}:{}", days, hours, minutes, seconds)
+    format!(
+        "{}d {}:{}:{}.{}",
+        days, hours, minutes, seconds, milliseconds
+    )
 }

src/messages.rs

@@ -2,14 +2,12 @@
 /// and handle TcpStream (TCP socket).
 use bytes::{Buf, BufMut, BytesMut};
 use md5::{Digest, Md5};
-use tokio::io::{AsyncReadExt, AsyncWriteExt, BufReader};
-use tokio::net::{
-    tcp::{OwnedReadHalf, OwnedWriteHalf},
-    TcpStream,
-};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpStream;
 
 use crate::errors::Error;
 use std::collections::HashMap;
+use std::mem;
 
 /// Postgres data type mappings
 /// used in RowDescription ('T') message.
@@ -30,7 +28,10 @@ impl From<&DataType> for i32 {
 }
 
 /// Tell the client that authentication handshake completed successfully.
-pub async fn auth_ok(stream: &mut TcpStream) -> Result<(), Error> {
+pub async fn auth_ok<S>(stream: &mut S) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut auth_ok = BytesMut::with_capacity(9);
 
     auth_ok.put_u8(b'R');
@@ -41,7 +42,10 @@ pub async fn auth_ok(stream: &mut TcpStream) -> Result<(), Error> {
 }
 
 /// Generate md5 password challenge.
-pub async fn md5_challenge(stream: &mut TcpStream) -> Result<[u8; 4], Error> {
+pub async fn md5_challenge<S>(stream: &mut S) -> Result<[u8; 4], Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     // let mut rng = rand::thread_rng();
     let salt: [u8; 4] = [
         rand::random(),
@@ -62,11 +66,14 @@ pub async fn md5_challenge(stream: &mut TcpStream) -> Result<[u8; 4], Error> {
 
 /// Give the client the process_id and secret we generated
 /// used in query cancellation.
-pub async fn backend_key_data(
-    stream: &mut TcpStream,
+pub async fn backend_key_data<S>(
+    stream: &mut S,
     backend_id: i32,
     secret_key: i32,
-) -> Result<(), Error> {
+) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut key_data = BytesMut::from(&b"K"[..]);
     key_data.put_i32(12);
     key_data.put_i32(backend_id);
@@ -87,8 +94,13 @@ pub fn simple_query(query: &str) -> BytesMut {
 }
 
 /// Tell the client we're ready for another query.
-pub async fn ready_for_query(stream: &mut TcpStream) -> Result<(), Error> {
-    let mut bytes = BytesMut::with_capacity(5);
+pub async fn ready_for_query<S>(stream: &mut S) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
+    let mut bytes = BytesMut::with_capacity(
+        mem::size_of::<u8>() + mem::size_of::<i32>() + mem::size_of::<u8>(),
+    );
 
     bytes.put_u8(b'Z');
     bytes.put_i32(5);
@@ -205,12 +217,15 @@ pub fn md5_hash_password(user: &str, password: &str, salt: &[u8]) -> Vec<u8> {
 
 /// Send password challenge response to the server.
 /// This is the MD5 challenge.
-pub async fn md5_password(
-    stream: &mut TcpStream,
+pub async fn md5_password<S>(
+    stream: &mut S,
     user: &str,
     password: &str,
     salt: &[u8],
-) -> Result<(), Error> {
+) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let password = md5_hash_password(user, password, salt);
 
     let mut message = BytesMut::with_capacity(password.len() as usize + 5);
@@ -225,10 +240,10 @@ pub async fn md5_password(
 /// Implements a response to our custom `SET SHARDING KEY`
 /// and `SET SERVER ROLE` commands.
 /// This tells the client we're ready for the next query.
-pub async fn custom_protocol_response_ok(
-    stream: &mut OwnedWriteHalf,
-    message: &str,
-) -> Result<(), Error> {
+pub async fn custom_protocol_response_ok<S>(stream: &mut S, message: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut res = BytesMut::with_capacity(25);
 
     let set_complete = BytesMut::from(&format!("{}\0", message)[..]);
@@ -239,18 +254,28 @@ pub async fn custom_protocol_response_ok(
     res.put_i32(len);
     res.put_slice(&set_complete[..]);
 
-    // ReadyForQuery (idle)
-    res.put_u8(b'Z');
-    res.put_i32(5);
-    res.put_u8(b'I');
-
-    write_all_half(stream, res).await
+    write_all_half(stream, res).await?;
+    ready_for_query(stream).await
 }
 
 /// Send a custom error message to the client.
 /// Tell the client we are ready for the next query and no rollback is necessary.
 /// Docs on error codes: <https://www.postgresql.org/docs/12/errcodes-appendix.html>.
-pub async fn error_response(stream: &mut OwnedWriteHalf, message: &str) -> Result<(), Error> {
+pub async fn error_response<S>(stream: &mut S, message: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
+    error_response_terminal(stream, message).await?;
+    ready_for_query(stream).await
+}
+
+/// Send a custom error message to the client.
+/// Tell the client we are ready for the next query and no rollback is necessary.
+/// Docs on error codes: <https://www.postgresql.org/docs/12/errcodes-appendix.html>.
+pub async fn error_response_terminal<S>(stream: &mut S, message: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut error = BytesMut::new();
 
     // Error level
@@ -272,26 +297,20 @@ pub async fn error_response(stream: &mut OwnedWriteHalf, message: &str) -> Resul
     // No more fields follow.
     error.put_u8(0);
 
-    // Ready for query, no rollback needed (I = idle).
-    let mut ready_for_query = BytesMut::new();
-
-    ready_for_query.put_u8(b'Z');
-    ready_for_query.put_i32(5);
-    ready_for_query.put_u8(b'I');
-
     // Compose the two message reply.
-    let mut res = BytesMut::with_capacity(error.len() + ready_for_query.len() + 5);
+    let mut res = BytesMut::with_capacity(error.len() + 5);
 
     res.put_u8(b'E');
     res.put_i32(error.len() as i32 + 4);
-
     res.put(error);
-    res.put(ready_for_query);
 
     Ok(write_all_half(stream, res).await?)
 }
 
-pub async fn wrong_password(stream: &mut TcpStream, user: &str) -> Result<(), Error> {
+pub async fn wrong_password<S>(stream: &mut S, user: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     let mut error = BytesMut::new();
 
     // Error level
@@ -325,11 +344,10 @@ pub async fn wrong_password(stream: &mut TcpStream, user: &str) -> Result<(), Er
 }
 
 /// Respond to a SHOW SHARD command.
-pub async fn show_response(
-    stream: &mut OwnedWriteHalf,
-    name: &str,
-    value: &str,
-) -> Result<(), Error> {
+pub async fn show_response<S>(stream: &mut S, name: &str, value: &str) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     // A SELECT response consists of:
     // 1. RowDescription
     // 2. One or more DataRow
@@ -348,12 +366,8 @@ pub async fn show_response(
     // CommandComplete
     res.put(command_complete("SELECT 1"));
 
-    // ReadyForQuery
-    res.put_u8(b'Z');
-    res.put_i32(5);
-    res.put_u8(b'I');
-
-    write_all_half(stream, res).await
+    write_all_half(stream, res).await?;
+    ready_for_query(stream).await
 }
 
 pub fn row_description(columns: &Vec<(&str, DataType)>) -> BytesMut {
@@ -430,7 +444,10 @@ pub fn command_complete(command: &str) -> BytesMut {
 }
 
 /// Write all data in the buffer to the TcpStream.
-pub async fn write_all(stream: &mut TcpStream, buf: BytesMut) -> Result<(), Error> {
+pub async fn write_all<S>(stream: &mut S, buf: BytesMut) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     match stream.write_all(&buf).await {
         Ok(_) => Ok(()),
         Err(_) => return Err(Error::SocketError),
@@ -438,7 +455,10 @@ pub async fn write_all(stream: &mut TcpStream, buf: BytesMut) -> Result<(), Erro
 }
 
 /// Write all the data in the buffer to the TcpStream, write owned half (see mpsc).
-pub async fn write_all_half(stream: &mut OwnedWriteHalf, buf: BytesMut) -> Result<(), Error> {
+pub async fn write_all_half<S>(stream: &mut S, buf: BytesMut) -> Result<(), Error>
+where
+    S: tokio::io::AsyncWrite + std::marker::Unpin,
+{
     match stream.write_all(&buf).await {
         Ok(_) => Ok(()),
         Err(_) => return Err(Error::SocketError),
@@ -446,7 +466,10 @@ pub async fn write_all_half(stream: &mut OwnedWriteHalf, buf: BytesMut) -> Resul
 }
 
 /// Read a complete message from the socket.
-pub async fn read_message(stream: &mut BufReader<OwnedReadHalf>) -> Result<BytesMut, Error> {
+pub async fn read_message<S>(stream: &mut S) -> Result<BytesMut, Error>
+where
+    S: tokio::io::AsyncRead + std::marker::Unpin,
+{
     let code = match stream.read_u8().await {
         Ok(code) => code,
         Err(_) => return Err(Error::SocketError),
@@ -472,3 +495,20 @@ pub async fn read_message(stream: &mut BufReader<OwnedReadHalf>) -> Result<Bytes
 
     Ok(bytes)
 }
+
+pub fn server_paramater_message(key: &str, value: &str) -> BytesMut {
+    let mut server_info = BytesMut::new();
+
+    let null_byte_size = 1;
+    let len: usize =
+        mem::size_of::<i32>() + key.len() + null_byte_size + value.len() + null_byte_size;
+
+    server_info.put_slice("S".as_bytes());
+    server_info.put_i32(len.try_into().unwrap());
+    server_info.put_slice(key.as_bytes());
+    server_info.put_bytes(0, 1);
+    server_info.put_slice(value.as_bytes());
+    server_info.put_bytes(0, 1);
+
+    return server_info;
+}

src/pool.rs

@@ -1,119 +1,274 @@
-/// Pooling, failover and banlist.
+use arc_swap::ArcSwap;
 use async_trait::async_trait;
 use bb8::{ManageConnection, Pool, PooledConnection};
 use bytes::BytesMut;
 use chrono::naive::NaiveDateTime;
 use log::{debug, error, info, warn};
+use once_cell::sync::Lazy;
 use parking_lot::{Mutex, RwLock};
+use rand::seq::SliceRandom;
+use rand::thread_rng;
+use regex::Regex;
 use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::Instant;
 
 use crate::config::{get_config, Address, Role, User};
 use crate::errors::Error;
+
 use crate::server::Server;
-use crate::stats::Reporter;
+use crate::sharding::ShardingFunction;
+use crate::stats::{get_reporter, Reporter};
 
 pub type BanList = Arc<RwLock<Vec<HashMap<Address, NaiveDateTime>>>>;
-pub type ClientServerMap = Arc<Mutex<HashMap<(i32, i32), (i32, i32, String, String)>>>;
+pub type ClientServerMap = Arc<Mutex<HashMap<(i32, i32), (i32, i32, String, u16)>>>;
+pub type PoolMap = HashMap<(String, String), ConnectionPool>;
+/// The connection pool, globally available.
+/// This is atomic and safe and read-optimized.
+/// The pool is recreated dynamically when the config is reloaded.
+pub static POOLS: Lazy<ArcSwap<PoolMap>> = Lazy::new(|| ArcSwap::from_pointee(HashMap::default()));
+
+/// Pool mode:
+/// - transaction: server serves one transaction,
+/// - session: server is attached to the client.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum PoolMode {
+    Session,
+    Transaction,
+}
+
+impl std::fmt::Display for PoolMode {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match *self {
+            PoolMode::Session => write!(f, "session"),
+            PoolMode::Transaction => write!(f, "transaction"),
+        }
+    }
+}
+
+/// Pool settings.
+#[derive(Clone, Debug)]
+pub struct PoolSettings {
+    /// Transaction or Session.
+    pub pool_mode: PoolMode,
+
+    // Number of shards.
+    pub shards: usize,
+
+    // Connecting user.
+    pub user: User,
+
+    // Default server role to connect to.
+    pub default_role: Option<Role>,
+
+    // Enable/disable query parser.
+    pub query_parser_enabled: bool,
+
+    // Read from the primary as well or not.
+    pub primary_reads_enabled: bool,
+
+    // Sharding function.
+    pub sharding_function: ShardingFunction,
+
+    // Automatically detect sharding key in query.
+    pub sharding_key_regex: Option<Regex>,
+}
+
+impl Default for PoolSettings {
+    fn default() -> PoolSettings {
+        PoolSettings {
+            pool_mode: PoolMode::Transaction,
+            shards: 1,
+            user: User::default(),
+            default_role: None,
+            query_parser_enabled: false,
+            primary_reads_enabled: true,
+            sharding_function: ShardingFunction::PgBigintHash,
+            sharding_key_regex: None,
+        }
+    }
+}
 
 /// The globally accessible connection pool.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct ConnectionPool {
+    /// The pools handled internally by bb8.
     databases: Vec<Vec<Pool<ServerPool>>>,
+
+    /// The addresses (host, port, role) to handle
+    /// failover and load balancing deterministically.
     addresses: Vec<Vec<Address>>,
-    round_robin: usize,
+
+    /// List of banned addresses (see above)
+    /// that should not be queried.
     banlist: BanList,
+
+    /// The statistics aggregator runs in a separate task
+    /// and receives stats from clients, servers, and the pool.
     stats: Reporter,
+
+    /// The server information (K messages) have to be passed to the
+    /// clients on startup. We pre-connect to all shards and replicas
+    /// on pool creation and save the K messages here.
+    server_info: BytesMut,
+
+    /// Pool configuration.
+    pub settings: PoolSettings,
 }
 
 impl ConnectionPool {
     /// Construct the connection pool from the configuration.
-    pub async fn from_config(
-        client_server_map: ClientServerMap,
-        stats: Reporter,
-    ) -> ConnectionPool {
+    pub async fn from_config(client_server_map: ClientServerMap) -> Result<(), Error> {
         let config = get_config();
-        let mut shards = Vec::new();
-        let mut addresses = Vec::new();
-        let mut banlist = Vec::new();
+
+        let mut new_pools = HashMap::new();
         let mut address_id = 0;
-        let mut shard_ids = config
-            .shards
-            .clone()
-            .into_keys()
-            .map(|x| x.to_string())
-            .collect::<Vec<String>>();
-        shard_ids.sort_by_key(|k| k.parse::<i64>().unwrap());
 
-        for shard_idx in shard_ids {
-            let shard = &config.shards[&shard_idx];
-            let mut pools = Vec::new();
-            let mut servers = Vec::new();
-            let mut replica_number = 0;
+        for (pool_name, pool_config) in &config.pools {
+            // There is one pool per database/user pair.
+            for (_, user) in &pool_config.users {
+                let mut shards = Vec::new();
+                let mut addresses = Vec::new();
+                let mut banlist = Vec::new();
+                let mut shard_ids = pool_config
+                    .shards
+                    .clone()
+                    .into_keys()
+                    .map(|x| x.to_string())
+                    .collect::<Vec<String>>();
 
-            for server in shard.servers.iter() {
-                let role = match server.2.as_ref() {
-                    "primary" => Role::Primary,
-                    "replica" => Role::Replica,
-                    _ => {
-                        error!("Config error: server role can be 'primary' or 'replica', have: '{}'. Defaulting to 'replica'.", server.2);
-                        Role::Replica
+                // Sort by shard number to ensure consistency.
+                shard_ids.sort_by_key(|k| k.parse::<i64>().unwrap());
+
+                for shard_idx in &shard_ids {
+                    let shard = &pool_config.shards[shard_idx];
+                    let mut pools = Vec::new();
+                    let mut servers = Vec::new();
+                    let mut address_index = 0;
+                    let mut replica_number = 0;
+
+                    for server in shard.servers.iter() {
+                        let role = match server.2.as_ref() {
+                            "primary" => Role::Primary,
+                            "replica" => Role::Replica,
+                            _ => {
+                                error!("Config error: server role can be 'primary' or 'replica', have: '{}'. Defaulting to 'replica'.", server.2);
+                                Role::Replica
+                            }
+                        };
+
+                        let address = Address {
+                            id: address_id,
+                            database: shard.database.clone(),
+                            host: server.0.clone(),
+                            port: server.1 as u16,
+                            role: role,
+                            address_index,
+                            replica_number,
+                            shard: shard_idx.parse::<usize>().unwrap(),
+                            username: user.username.clone(),
+                            pool_name: pool_name.clone(),
+                        };
+
+                        address_id += 1;
+                        address_index += 1;
+
+                        if role == Role::Replica {
+                            replica_number += 1;
+                        }
+
+                        let manager = ServerPool::new(
+                            address.clone(),
+                            user.clone(),
+                            &shard.database,
+                            client_server_map.clone(),
+                            get_reporter(),
+                        );
+
+                        let pool = Pool::builder()
+                            .max_size(user.pool_size)
+                            .connection_timeout(std::time::Duration::from_millis(
+                                config.general.connect_timeout,
+                            ))
+                            .test_on_check_out(false)
+                            .build(manager)
+                            .await
+                            .unwrap();
+
+                        pools.push(pool);
+                        servers.push(address);
+                    }
+
+                    shards.push(pools);
+                    addresses.push(servers);
+                    banlist.push(HashMap::new());
+                }
+
+                assert_eq!(shards.len(), addresses.len());
+
+                let mut pool = ConnectionPool {
+                    databases: shards,
+                    addresses: addresses,
+                    banlist: Arc::new(RwLock::new(banlist)),
+                    stats: get_reporter(),
+                    server_info: BytesMut::new(),
+                    settings: PoolSettings {
+                        pool_mode: match pool_config.pool_mode.as_str() {
+                            "transaction" => PoolMode::Transaction,
+                            "session" => PoolMode::Session,
+                            _ => unreachable!(),
+                        },
+                        // shards: pool_config.shards.clone(),
+                        shards: shard_ids.len(),
+                        user: user.clone(),
+                        default_role: match pool_config.default_role.as_str() {
+                            "any" => None,
+                            "replica" => Some(Role::Replica),
+                            "primary" => Some(Role::Primary),
+                            _ => unreachable!(),
+                        },
+                        query_parser_enabled: pool_config.query_parser_enabled.clone(),
+                        primary_reads_enabled: pool_config.primary_reads_enabled,
+                        sharding_function: match pool_config.sharding_function.as_str() {
+                            "pg_bigint_hash" => ShardingFunction::PgBigintHash,
+                            "sha1" => ShardingFunction::Sha1,
+                            _ => unreachable!(),
+                        },
+                        sharding_key_regex: match &pool_config.sharding_key {
+                            Some(sharding_key) => match Regex::new(&format!(
+                                r"(?i) *{} *= *'?([0-9]+)'?",
+                                sharding_key
+                            )) {
+                                Ok(regex) => Some(regex),
+                                Err(err) => {
+                                    error!("Sharding key regex error: {:?}", err);
+                                    return Err(Error::BadConfig);
+                                }
+                            },
+
+                            None => None,
+                        },
+                    },
+                };
+
+                // Connect to the servers to make sure pool configuration is valid
+                // before setting it globally.
+                match pool.validate().await {
+                    Ok(_) => (),
+                    Err(err) => {
+                        error!("Could not validate connection pool: {:?}", err);
+                        return Err(err);
                     }
                 };
 
-                let address = Address {
-                    id: address_id,
-                    host: server.0.clone(),
-                    port: server.1.to_string(),
-                    role: role,
-                    replica_number,
-                    shard: shard_idx.parse::<usize>().unwrap(),
-                };
-
-                address_id += 1;
-
-                if role == Role::Replica {
-                    replica_number += 1;
-                }
-
-                let manager = ServerPool::new(
-                    address.clone(),
-                    config.user.clone(),
-                    &shard.database,
-                    client_server_map.clone(),
-                    stats.clone(),
-                );
-
-                let pool = Pool::builder()
-                    .max_size(config.general.pool_size)
-                    .connection_timeout(std::time::Duration::from_millis(
-                        config.general.connect_timeout,
-                    ))
-                    .test_on_check_out(false)
-                    .build(manager)
-                    .await
-                    .unwrap();
-
-                pools.push(pool);
-                servers.push(address);
+                // There is one pool per database/user pair.
+                new_pools.insert((pool_name.clone(), user.username.clone()), pool);
             }
-
-            shards.push(pools);
-            addresses.push(servers);
-            banlist.push(HashMap::new());
         }
 
-        assert_eq!(shards.len(), addresses.len());
-        let address_len = addresses.len();
+        POOLS.store(Arc::new(new_pools.clone()));
 
-        ConnectionPool {
-            databases: shards,
-            addresses: addresses,
-            round_robin: rand::random::<usize>() % address_len, // Start at a random replica
-            banlist: Arc::new(RwLock::new(banlist)),
-            stats: stats,
-        }
+        Ok(())
     }
 
     /// Connect to all shards and grab server information.
@@ -121,16 +276,11 @@ impl ConnectionPool {
     /// when they connect.
     /// This also warms up the pool for clients that connect when
     /// the pooler starts up.
-    pub async fn validate(&mut self) -> Result<BytesMut, Error> {
+    async fn validate(&mut self) -> Result<(), Error> {
         let mut server_infos = Vec::new();
-
-        let stats = self.stats.clone();
         for shard in 0..self.shards() {
-            for _ in 0..self.servers(shard) {
-                // To keep stats consistent.
-                let fake_process_id = 0;
-
-                let connection = match self.get(shard, None, fake_process_id).await {
+            for server in 0..self.servers(shard) {
+                let connection = match self.databases[shard][server].get().await {
                     Ok(conn) => conn,
                     Err(err) => {
                         error!("Shard {} down or misconfigured: {:?}", shard, err);
@@ -138,20 +288,16 @@ impl ConnectionPool {
                     }
                 };
 
-                let mut proxy = connection.0;
-                let address = connection.1;
-                let server = &mut *proxy;
-
+                let proxy = connection;
+                let server = &*proxy;
                 let server_info = server.server_info();
 
-                stats.client_disconnecting(fake_process_id, address.id);
-
                 if server_infos.len() > 0 {
                     // Compare against the last server checked.
                     if server_info != server_infos[server_infos.len() - 1] {
                         warn!(
                             "{:?} has different server configuration than the last server",
-                            address
+                            proxy.address()
                         );
                     }
                 }
@@ -166,59 +312,41 @@ impl ConnectionPool {
             return Err(Error::AllServersDown);
         }
 
-        Ok(server_infos[0].clone())
+        // We're assuming all servers are identical.
+        // TODO: not true.
+        self.server_info = server_infos[0].clone();
+
+        Ok(())
     }
 
     /// Get a connection from the pool.
     pub async fn get(
-        &mut self,
-        shard: usize,
-        role: Option<Role>,
-        process_id: i32,
+        &self,
+        shard: usize,       // shard number
+        role: Option<Role>, // primary or replica
+        process_id: i32,    // client id
     ) -> Result<(PooledConnection<'_, ServerPool>, Address), Error> {
         let now = Instant::now();
-        let addresses = &self.addresses[shard];
+        let mut candidates: Vec<&Address> = self.addresses[shard]
+            .iter()
+            .filter(|address| address.role == role)
+            .collect();
 
-        let mut allowed_attempts = match role {
-            // Primary-specific queries get one attempt, if the primary is down,
-            // nothing we should do about it I think. It's dangerous to retry
-            // write queries.
-            Some(Role::Primary) => 1,
+        // Random load balancing
+        candidates.shuffle(&mut thread_rng());
 
-            // Replicas get to try as many times as there are replicas
-            // and connections in the pool.
-            _ => addresses.len(),
-        };
+        let healthcheck_timeout = get_config().general.healthcheck_timeout;
+        let healthcheck_delay = get_config().general.healthcheck_delay as u128;
 
-        debug!("Allowed attempts for {:?}: {}", role, allowed_attempts);
+        while !candidates.is_empty() {
+            // Get the next candidate
+            let address = match candidates.pop() {
+                Some(address) => address,
+                None => break,
+            };
 
-        let exists = match role {
-            Some(role) => addresses.iter().filter(|addr| addr.role == role).count() > 0,
-            None => true,
-        };
-
-        if !exists {
-            error!("Requested role {:?}, but none are configured", role);
-            return Err(Error::BadConfig);
-        }
-
-        while allowed_attempts > 0 {
-            // Round-robin replicas.
-            self.round_robin += 1;
-
-            let index = self.round_robin % addresses.len();
-            let address = &addresses[index];
-
-            // Make sure you're getting a primary or a replica
-            // as per request. If no specific role is requested, the first
-            // available will be chosen.
-            if address.role != role {
-                continue;
-            }
-
-            allowed_attempts -= 1;
-
-            if self.is_banned(address, shard, role) {
+            if self.is_banned(&address, role) {
+                debug!("Address {:?} is banned", address);
                 continue;
             }
 
@@ -226,12 +354,14 @@ impl ConnectionPool {
             self.stats.client_waiting(process_id, address.id);
 
             // Check if we can connect
-            let mut conn = match self.databases[shard][index].get().await {
+            let mut conn = match self.databases[address.shard][address.address_index]
+                .get()
+                .await
+            {
                 Ok(conn) => conn,
                 Err(err) => {
-                    error!("Banning replica {}, error: {:?}", index, err);
-                    self.ban(address, shard);
-                    self.stats.client_disconnecting(process_id, address.id);
+                    error!("Banning instance {:?}, error: {:?}", address, err);
+                    self.ban(&address, process_id);
                     self.stats
                         .checkout_time(now.elapsed().as_micros(), process_id, address.id);
                     continue;
@@ -240,13 +370,28 @@ impl ConnectionPool {
 
             // // Check if this server is alive with a health check.
             let server = &mut *conn;
-            let healthcheck_timeout = get_config().general.healthcheck_timeout;
+
+            // Will return error if timestamp is greater than current system time, which it should never be set to
+            let require_healthcheck =
+                server.last_activity().elapsed().unwrap().as_millis() > healthcheck_delay;
+
+            // Do not issue a health check unless it's been a little while
+            // since we last checked the server is ok.
+            // Health checks are pretty expensive.
+            if !require_healthcheck {
+                self.stats
+                    .checkout_time(now.elapsed().as_micros(), process_id, address.id);
+                self.stats.server_active(conn.process_id(), address.id);
+                return Ok((conn, address.clone()));
+            }
+
+            debug!("Running health check on server {:?}", address);
 
             self.stats.server_tested(server.process_id(), address.id);
 
             match tokio::time::timeout(
                 tokio::time::Duration::from_millis(healthcheck_timeout),
-                server.query("SELECT 1"),
+                server.query(";"), // Cheap query (query parser not used in PG)
             )
             .await
             {
@@ -255,69 +400,72 @@ impl ConnectionPool {
                     Ok(_) => {
                         self.stats
                             .checkout_time(now.elapsed().as_micros(), process_id, address.id);
-                        self.stats.server_idle(conn.process_id(), address.id);
+                        self.stats.server_active(conn.process_id(), address.id);
                         return Ok((conn, address.clone()));
                     }
 
                     // Health check failed.
-                    Err(_) => {
-                        error!("Banning replica {} because of failed health check", index);
+                    Err(err) => {
+                        error!(
+                            "Banning instance {:?} because of failed health check, {:?}",
+                            address, err
+                        );
 
                         // Don't leave a bad connection in the pool.
                         server.mark_bad();
 
-                        self.ban(address, shard);
-                        self.stats.client_disconnecting(process_id, address.id);
-                        self.stats
-                            .checkout_time(now.elapsed().as_micros(), process_id, address.id);
+                        self.ban(&address, process_id);
                         continue;
                     }
                 },
 
                 // Health check timed out.
-                Err(_) => {
-                    error!("Banning replica {} because of health check timeout", index);
+                Err(err) => {
+                    error!(
+                        "Banning instance {:?} because of health check timeout, {:?}",
+                        address, err
+                    );
                     // Don't leave a bad connection in the pool.
                     server.mark_bad();
 
-                    self.ban(address, shard);
-                    self.stats.client_disconnecting(process_id, address.id);
-                    self.stats
-                        .checkout_time(now.elapsed().as_micros(), process_id, address.id);
+                    self.ban(&address, process_id);
                     continue;
                 }
             }
         }
 
-        return Err(Error::AllServersDown);
+        Err(Error::AllServersDown)
     }
 
     /// Ban an address (i.e. replica). It no longer will serve
     /// traffic for any new transactions. Existing transactions on that replica
     /// will finish successfully or error out to the clients.
-    pub fn ban(&self, address: &Address, shard: usize) {
+    pub fn ban(&self, address: &Address, process_id: i32) {
+        self.stats.client_disconnecting(process_id, address.id);
+
         error!("Banning {:?}", address);
+
         let now = chrono::offset::Utc::now().naive_utc();
         let mut guard = self.banlist.write();
-        guard[shard].insert(address.clone(), now);
+        guard[address.shard].insert(address.clone(), now);
     }
 
     /// Clear the replica to receive traffic again. Takes effect immediately
     /// for all new transactions.
-    pub fn _unban(&self, address: &Address, shard: usize) {
+    pub fn _unban(&self, address: &Address) {
         let mut guard = self.banlist.write();
-        guard[shard].remove(address);
+        guard[address.shard].remove(address);
     }
 
     /// Check if a replica can serve traffic. If all replicas are banned,
     /// we unban all of them. Better to try then not to.
-    pub fn is_banned(&self, address: &Address, shard: usize, role: Option<Role>) -> bool {
+    pub fn is_banned(&self, address: &Address, role: Option<Role>) -> bool {
         let replicas_available = match role {
-            Some(Role::Replica) => self.addresses[shard]
+            Some(Role::Replica) => self.addresses[address.shard]
                 .iter()
                 .filter(|addr| addr.role == Role::Replica)
                 .count(),
-            None => self.addresses[shard].len(),
+            None => self.addresses[address.shard].len(),
             Some(Role::Primary) => return false, // Primary cannot be banned.
         };
 
@@ -326,17 +474,17 @@ impl ConnectionPool {
         let guard = self.banlist.read();
 
         // Everything is banned = nothing is banned.
-        if guard[shard].len() == replicas_available {
+        if guard[address.shard].len() == replicas_available {
             drop(guard);
             let mut guard = self.banlist.write();
-            guard[shard].clear();
+            guard[address.shard].clear();
             drop(guard);
             warn!("Unbanning all replicas.");
             return false;
         }
 
         // I expect this to miss 99.9999% of the time.
-        match guard[shard].get(address) {
+        match guard[address.shard].get(address) {
             Some(timestamp) => {
                 let now = chrono::offset::Utc::now().naive_utc();
                 let config = get_config();
@@ -346,7 +494,7 @@ impl ConnectionPool {
                     drop(guard);
                     warn!("Unbanning {:?}", address);
                     let mut guard = self.banlist.write();
-                    guard[shard].remove(address);
+                    guard[address.shard].remove(address);
                     false
                 } else {
                     debug!("{:?} is banned", address);
@@ -390,6 +538,10 @@ impl ConnectionPool {
     pub fn address(&self, shard: usize, server: usize) -> &Address {
         &self.addresses[shard][server]
     }
+
+    pub fn server_info(&self) -> BytesMut {
+        self.server_info.clone()
+    }
 }
 
 /// Wrapper for the bb8 connection pool.
@@ -426,11 +578,7 @@ impl ManageConnection for ServerPool {
 
     /// Attempts to create a new connection.
     async fn connect(&self) -> Result<Self::Connection, Self::Error> {
-        info!(
-            "Creating a new connection to {:?} using user {:?}",
-            self.address.name(),
-            self.user.name
-        );
+        info!("Creating a new server connection {:?}", self.address);
 
         // Put a temporary process_id into the stats
         // for server login.
@@ -470,3 +618,24 @@ impl ManageConnection for ServerPool {
         conn.is_bad()
     }
 }
+
+/// Get the connection pool
+pub fn get_pool(db: String, user: String) -> Option<ConnectionPool> {
+    match get_all_pools().get(&(db, user)) {
+        Some(pool) => Some(pool.clone()),
+        None => None,
+    }
+}
+
+/// How many total servers we have in the config.
+pub fn get_number_of_addresses() -> usize {
+    get_all_pools()
+        .iter()
+        .map(|(_, pool)| pool.databases())
+        .sum()
+}
+
+/// Get a pointer to all configured pools.
+pub fn get_all_pools() -> HashMap<(String, String), ConnectionPool> {
+    return (*(*POOLS.load())).clone();
+}

src/prometheus.rs

@@ -0,0 +1,210 @@
+use hyper::service::{make_service_fn, service_fn};
+use hyper::{Body, Method, Request, Response, Server, StatusCode};
+use log::{error, info, warn};
+use phf::phf_map;
+use std::collections::HashMap;
+use std::fmt;
+use std::net::SocketAddr;
+
+use crate::config::Address;
+use crate::pool::get_all_pools;
+use crate::stats::get_stats;
+
+struct MetricHelpType {
+    help: &'static str,
+    ty: &'static str,
+}
+
+// reference for metric types: https://prometheus.io/docs/concepts/metric_types/
+// counters only increase
+// gauges can arbitrarily increase or decrease
+static METRIC_HELP_AND_TYPES_LOOKUP: phf::Map<&'static str, MetricHelpType> = phf_map! {
+    "total_query_count" => MetricHelpType {
+        help: "Number of queries sent by all clients",
+        ty: "counter",
+    },
+    "total_query_time" => MetricHelpType {
+        help: "Total amount of time for queries to execute",
+        ty: "counter",
+    },
+    "total_received" => MetricHelpType {
+        help: "Number of bytes received from the server",
+        ty: "counter",
+    },
+    "total_sent" => MetricHelpType {
+        help: "Number of bytes sent to the server",
+        ty: "counter",
+    },
+    "total_xact_count" => MetricHelpType {
+        help: "Total number of transactions started by the client",
+        ty: "counter",
+    },
+    "total_xact_time" => MetricHelpType {
+        help: "Total amount of time for all transactions to execute",
+        ty: "counter",
+    },
+    "total_wait_time" => MetricHelpType {
+        help: "Total time client waited for a server connection",
+        ty: "counter",
+    },
+    "avg_query_count" => MetricHelpType {
+        help: "Average of total_query_count every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_query_time" => MetricHelpType {
+        help: "Average time taken for queries to execute every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_recv" => MetricHelpType {
+        help: "Average of total_received bytes every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_sent" => MetricHelpType {
+        help: "Average of total_sent bytes every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_xact_count" => MetricHelpType {
+        help: "Average of total_xact_count every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_xact_time" => MetricHelpType {
+        help: "Average of total_xact_time every 15 seconds",
+        ty: "gauge",
+    },
+    "avg_wait_time" => MetricHelpType {
+        help: "Average of total_wait_time every 15 seconds",
+        ty: "gauge",
+    },
+    "maxwait_us" => MetricHelpType {
+        help: "The time a client waited for a server connection in microseconds",
+        ty: "gauge",
+    },
+    "maxwait" => MetricHelpType {
+        help: "The time a client waited for a server connection in seconds",
+        ty: "gauge",
+    },
+    "cl_waiting" => MetricHelpType {
+        help: "How many clients are waiting for a connection from the pool",
+        ty: "gauge",
+    },
+    "cl_active" => MetricHelpType {
+        help: "How many clients are actively communicating with a server",
+        ty: "gauge",
+    },
+    "cl_idle" => MetricHelpType {
+        help: "How many clients are idle",
+        ty: "gauge",
+    },
+    "sv_idle" => MetricHelpType {
+        help: "How many server connections are idle",
+        ty: "gauge",
+    },
+    "sv_active" => MetricHelpType {
+        help: "How many server connections are actively communicating with a client",
+        ty: "gauge",
+    },
+    "sv_login" => MetricHelpType {
+        help: "How many server connections are currently being created",
+        ty: "gauge",
+    },
+    "sv_tested" => MetricHelpType {
+        help: "How many server connections are currently waiting on a health check to succeed",
+        ty: "gauge",
+    },
+};
+
+struct PrometheusMetric {
+    name: String,
+    help: String,
+    ty: String,
+    labels: HashMap<&'static str, String>,
+    value: i64,
+}
+
+impl fmt::Display for PrometheusMetric {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let formatted_labels = self
+            .labels
+            .iter()
+            .map(|(key, value)| format!("{}=\"{}\"", key, value))
+            .collect::<Vec<_>>()
+            .join(",");
+        write!(
+            f,
+            "# HELP {name} {help}\n# TYPE {name} {ty}\n{name}{{{formatted_labels}}} {value}\n",
+            name = format_args!("pgcat_{}", self.name),
+            help = self.help,
+            ty = self.ty,
+            formatted_labels = formatted_labels,
+            value = self.value
+        )
+    }
+}
+
+impl PrometheusMetric {
+    fn new(address: &Address, name: &str, value: i64) -> Option<PrometheusMetric> {
+        let mut labels = HashMap::new();
+        labels.insert("host", address.host.clone());
+        labels.insert("shard", address.shard.to_string());
+        labels.insert("role", address.role.to_string());
+        labels.insert("database", address.database.to_string());
+
+        METRIC_HELP_AND_TYPES_LOOKUP
+            .get(name)
+            .map(|metric| PrometheusMetric {
+                name: name.to_owned(),
+                help: metric.help.to_owned(),
+                ty: metric.ty.to_owned(),
+                labels,
+                value,
+            })
+    }
+}
+
+async fn prometheus_stats(request: Request<Body>) -> Result<Response<Body>, hyper::http::Error> {
+    match (request.method(), request.uri().path()) {
+        (&Method::GET, "/metrics") => {
+            let stats = get_stats();
+
+            let mut lines = Vec::new();
+            for (_, pool) in get_all_pools() {
+                for shard in 0..pool.shards() {
+                    for server in 0..pool.servers(shard) {
+                        let address = pool.address(shard, server);
+                        if let Some(address_stats) = stats.get(&address.id) {
+                            for (key, value) in address_stats.iter() {
+                                if let Some(prometheus_metric) =
+                                    PrometheusMetric::new(address, key, *value)
+                                {
+                                    lines.push(prometheus_metric.to_string());
+                                } else {
+                                    warn!("Metric {} not implemented for {}", key, address.name());
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+
+            Response::builder()
+                .header("content-type", "text/plain; version=0.0.4")
+                .body(lines.join("\n").into())
+        }
+        _ => Response::builder()
+            .status(StatusCode::NOT_FOUND)
+            .body("".into()),
+    }
+}
+
+pub async fn start_metric_server(http_addr: SocketAddr) {
+    let http_service_factory =
+        make_service_fn(|_conn| async { Ok::<_, hyper::Error>(service_fn(prometheus_stats)) });
+    let server = Server::bind(&http_addr.into()).serve(http_service_factory);
+    info!(
+        "Exposing prometheus metrics on http://{}/metrics.",
+        http_addr
+    );
+    if let Err(e) = server.await {
+        error!("Failed to run HTTP server: {}.", e);
+    }
+}

src/query_router.rs

@@ -8,16 +8,19 @@ use sqlparser::ast::Statement::{Query, StartTransaction};
 use sqlparser::dialect::PostgreSqlDialect;
 use sqlparser::parser::Parser;
 
-use crate::config::{get_config, Role};
-use crate::sharding::{Sharder, ShardingFunction};
+use crate::config::Role;
+use crate::pool::PoolSettings;
+use crate::sharding::Sharder;
 
 /// Regexes used to parse custom commands.
-const CUSTOM_SQL_REGEXES: [&str; 5] = [
+const CUSTOM_SQL_REGEXES: [&str; 7] = [
     r"(?i)^ *SET SHARDING KEY TO '?([0-9]+)'? *;? *$",
     r"(?i)^ *SET SHARD TO '?([0-9]+|ANY)'? *;? *$",
     r"(?i)^ *SHOW SHARD *;? *$",
     r"(?i)^ *SET SERVER ROLE TO '(PRIMARY|REPLICA|ANY|AUTO|DEFAULT)' *;? *$",
     r"(?i)^ *SHOW SERVER ROLE *;? *$",
+    r"(?i)^ *SET PRIMARY READS TO '?(on|off|default)'? *;? *$",
+    r"(?i)^ *SHOW PRIMARY READS *;? *$",
 ];
 
 /// Custom commands.
@@ -28,6 +31,8 @@ pub enum Command {
     ShowShard,
     SetServerRole,
     ShowServerRole,
+    SetPrimaryReads,
+    ShowPrimaryReads,
 }
 
 /// Quickly test for match when a query is received.
@@ -38,31 +43,27 @@ static CUSTOM_SQL_REGEX_LIST: OnceCell<Vec<Regex>> = OnceCell::new();
 
 /// The query router.
 pub struct QueryRouter {
-    /// By default, queries go here, unless we have better information
-    /// about what the client wants.
-    default_server_role: Option<Role>,
-
-    /// Number of shards in the cluster.
-    shards: usize,
-
     /// Which shard we should be talking to right now.
     active_shard: Option<usize>,
 
     /// Which server should we be talking to.
     active_role: Option<Role>,
 
+    /// Should we try to parse queries to route them to replicas or primary automatically
+    query_parser_enabled: bool,
+
     /// Include the primary into the replica pool for reads.
     primary_reads_enabled: bool,
 
-    /// Should we try to parse queries to route them to replicas or primary automatically.
-    query_parser_enabled: bool,
+    set_manually: bool,
 
-    /// Which sharding function we're using.
-    sharding_function: ShardingFunction,
+    /// Pool configuration.
+    pool_settings: PoolSettings,
 }
 
 impl QueryRouter {
-    /// One-time initialization of regexes.
+    /// One-time initialization of regexes
+    /// that parse our custom SQL protocol.
     pub fn setup() -> bool {
         let set = match RegexSet::new(&CUSTOM_SQL_REGEXES) {
             Ok(rgx) => rgx,
@@ -77,10 +78,7 @@ impl QueryRouter {
             .map(|rgx| Regex::new(rgx).unwrap())
             .collect();
 
-        // Impossible
-        if list.len() != set.len() {
-            return false;
-        }
+        assert_eq!(list.len(), set.len());
 
         match CUSTOM_SQL_REGEX_LIST.set(list) {
             Ok(_) => true,
@@ -93,32 +91,26 @@ impl QueryRouter {
         }
     }
 
-    /// Create a new instance of the query router. Each client gets its own.
+    /// Create a new instance of the query router.
+    /// Each client gets its own.
     pub fn new() -> QueryRouter {
-        let config = get_config();
-
-        let default_server_role = match config.query_router.default_role.as_ref() {
-            "any" => None,
-            "primary" => Some(Role::Primary),
-            "replica" => Some(Role::Replica),
-            _ => unreachable!(),
-        };
-
-        let sharding_function = match config.query_router.sharding_function.as_ref() {
-            "pg_bigint_hash" => ShardingFunction::PgBigintHash,
-            "sha1" => ShardingFunction::Sha1,
-            _ => unreachable!(),
-        };
-
         QueryRouter {
-            default_server_role: default_server_role,
-            shards: config.shards.len(),
-
-            active_role: default_server_role,
             active_shard: None,
-            primary_reads_enabled: config.query_router.primary_reads_enabled,
-            query_parser_enabled: config.query_router.query_parser_enabled,
-            sharding_function,
+            active_role: None,
+            query_parser_enabled: false,
+            primary_reads_enabled: false,
+            set_manually: false,
+            pool_settings: PoolSettings::default(),
+        }
+    }
+
+    /// Pool settings can change because of a config reload.
+    pub fn update_pool_settings(&mut self, pool_settings: PoolSettings) {
+        self.pool_settings = pool_settings;
+
+        if !self.set_manually {
+            self.query_parser_enabled = self.pool_settings.query_parser_enabled;
+            self.primary_reads_enabled = self.pool_settings.primary_reads_enabled;
         }
     }
 
@@ -146,7 +138,10 @@ impl QueryRouter {
 
         let matches: Vec<_> = regex_set.matches(&query).into_iter().collect();
 
+        // This is not a custom query, try to infer which
+        // server it'll go to if the query parser is enabled.
         if matches.len() != 1 {
+            debug!("Regular query, not a command");
             return None;
         }
 
@@ -156,11 +151,16 @@ impl QueryRouter {
             2 => Command::ShowShard,
             3 => Command::SetServerRole,
             4 => Command::ShowServerRole,
+            5 => Command::SetPrimaryReads,
+            6 => Command::ShowPrimaryReads,
             _ => unreachable!(),
         };
 
         let mut value = match command {
-            Command::SetShardingKey | Command::SetShard | Command::SetServerRole => {
+            Command::SetShardingKey
+            | Command::SetShard
+            | Command::SetServerRole
+            | Command::SetPrimaryReads => {
                 // Capture value. I know this re-runs the regex engine, but I haven't
                 // figured out a better way just yet. I think I can write a single Regex
                 // that matches all 5 custom SQL patterns, but maybe that's not very legible?
@@ -187,11 +187,19 @@ impl QueryRouter {
                     }
                 }
             },
+
+            Command::ShowPrimaryReads => match self.primary_reads_enabled {
+                true => String::from("on"),
+                false => String::from("off"),
+            },
         };
 
         match command {
             Command::SetShardingKey => {
-                let sharder = Sharder::new(self.shards, self.sharding_function);
+                let sharder = Sharder::new(
+                    self.pool_settings.shards,
+                    self.pool_settings.sharding_function,
+                );
                 let shard = sharder.shard(value.parse::<i64>().unwrap());
                 self.active_shard = Some(shard);
                 value = shard.to_string();
@@ -199,12 +207,14 @@ impl QueryRouter {
 
             Command::SetShard => {
                 self.active_shard = match value.to_ascii_uppercase().as_ref() {
-                    "ANY" => Some(rand::random::<usize>() % self.shards),
+                    "ANY" => Some(rand::random::<usize>() % self.pool_settings.shards),
                     _ => Some(value.parse::<usize>().unwrap()),
                 };
             }
 
             Command::SetServerRole => {
+                self.set_manually = true;
+
                 self.active_role = match value.to_ascii_lowercase().as_ref() {
                     "primary" => {
                         self.query_parser_enabled = false;
@@ -227,8 +237,8 @@ impl QueryRouter {
                     }
 
                     "default" => {
-                        self.active_role = self.default_server_role;
-                        self.query_parser_enabled = get_config().query_router.query_parser_enabled;
+                        self.active_role = self.pool_settings.default_role;
+                        self.query_parser_enabled = self.pool_settings.query_parser_enabled;
                         self.active_role
                     }
 
@@ -236,6 +246,21 @@ impl QueryRouter {
                 };
             }
 
+            Command::SetPrimaryReads => {
+                self.set_manually = true;
+
+                if value == "on" {
+                    debug!("Setting primary reads to on");
+                    self.primary_reads_enabled = true;
+                } else if value == "off" {
+                    debug!("Setting primary reads to off");
+                    self.primary_reads_enabled = false;
+                } else if value == "default" {
+                    debug!("Setting primary reads to default");
+                    self.primary_reads_enabled = self.pool_settings.primary_reads_enabled;
+                }
+            }
+
             _ => (),
         }
 
@@ -243,7 +268,9 @@ impl QueryRouter {
     }
 
     /// Try to infer which server to connect to based on the contents of the query.
-    pub fn infer_role(&mut self, mut buf: BytesMut) -> bool {
+    pub fn infer_role_and_shard(&mut self, mut buf: BytesMut) -> bool {
+        debug!("Inferring role");
+
         let code = buf.get_u8() as char;
         let len = buf.get_i32() as usize;
 
@@ -282,6 +309,31 @@ impl QueryRouter {
             _ => return false,
         };
 
+        // First find the shard key
+        match &self.pool_settings.sharding_key_regex {
+            Some(re) => {
+                match re.captures(&query) {
+                    Some(group) => match group.get(1) {
+                        Some(value) => {
+                            let value = value.as_str().parse::<i64>().unwrap();
+                            let sharder = Sharder::new(
+                                self.pool_settings.shards,
+                                self.pool_settings.sharding_function,
+                            );
+                            let shard = sharder.shard(value);
+                            self.active_shard = Some(shard);
+
+                            debug!("Automatically routing to shard {}", shard);
+                        }
+                        None => (),
+                    },
+
+                    None => (),
+                };
+            }
+            None => (),
+        };
+
         let ast = match Parser::parse_sql(&PostgreSqlDialect {}, &query) {
             Ok(ast) => ast,
             Err(err) => {
@@ -330,29 +382,23 @@ impl QueryRouter {
         }
     }
 
-    /// Reset the router back to defaults.
-    /// This must be called at the end of every transaction in transaction mode.
-    pub fn _reset(&mut self) {
-        self.active_role = self.default_server_role;
-        self.active_shard = None;
+    pub fn set_shard(&mut self, shard: usize) {
+        self.active_shard = Some(shard);
     }
 
     /// Should we attempt to parse queries?
+    #[allow(dead_code)]
     pub fn query_parser_enabled(&self) -> bool {
         self.query_parser_enabled
     }
-
-    /// Allows to toggle primary reads in tests.
-    #[allow(dead_code)]
-    pub fn toggle_primary_reads(&mut self, value: bool) {
-        self.primary_reads_enabled = value;
-    }
 }
 
 #[cfg(test)]
 mod test {
     use super::*;
     use crate::messages::simple_query;
+    use crate::pool::PoolMode;
+    use crate::sharding::ShardingFunction;
     use bytes::BufMut;
 
     #[test]
@@ -364,30 +410,34 @@ mod test {
     }
 
     #[test]
-    fn test_infer_role_replica() {
+    fn test_infer_role_and_shard_replica() {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         assert!(qr.try_execute_command(simple_query("SET SERVER ROLE TO 'auto'")) != None);
         assert_eq!(qr.query_parser_enabled(), true);
-        qr.toggle_primary_reads(false);
+
+        assert!(qr.try_execute_command(simple_query("SET PRIMARY READS TO off")) != None);
 
         let queries = vec![
-            simple_query("SELECT * FROM items WHERE id = 5"),
+            simple_query("SELECT * FROM items WHERE id = 4"),
             simple_query(
                 "SELECT id, name, value FROM items INNER JOIN prices ON item.id = prices.item_id",
             ),
             simple_query("WITH t AS (SELECT * FROM items) SELECT * FROM t"),
         ];
 
-        for query in queries {
+        let shards = vec![0, 0, 0];
+
+        for (idx, query) in queries.iter().enumerate() {
             // It's a recognized query
-            assert!(qr.infer_role(query));
+            assert!(qr.infer_role_and_shard(query.clone()));
             assert_eq!(qr.role(), Some(Role::Replica));
+            assert_eq!(qr.shard(), shards[idx]);
         }
     }
 
     #[test]
-    fn test_infer_role_primary() {
+    fn test_infer_role_and_shard_primary() {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
 
@@ -400,28 +450,28 @@ mod test {
 
         for query in queries {
             // It's a recognized query
-            assert!(qr.infer_role(query));
+            assert!(qr.infer_role_and_shard(query));
             assert_eq!(qr.role(), Some(Role::Primary));
         }
     }
 
     #[test]
-    fn test_infer_role_primary_reads_enabled() {
+    fn test_infer_role_and_shard_primary_reads_enabled() {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         let query = simple_query("SELECT * FROM items WHERE id = 5");
-        qr.toggle_primary_reads(true);
+        assert!(qr.try_execute_command(simple_query("SET PRIMARY READS TO on")) != None);
 
-        assert!(qr.infer_role(query));
+        assert!(qr.infer_role_and_shard(query));
         assert_eq!(qr.role(), None);
     }
 
     #[test]
-    fn test_infer_role_parse_prepared() {
+    fn test_infer_role_and_shard_parse_prepared() {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         qr.try_execute_command(simple_query("SET SERVER ROLE TO 'auto'"));
-        qr.toggle_primary_reads(false);
+        assert!(qr.try_execute_command(simple_query("SET PRIMARY READS TO off")) != None);
 
         let prepared_stmt = BytesMut::from(
             &b"WITH t AS (SELECT * FROM items WHERE name = $1) SELECT * FROM t WHERE id = $2\0"[..],
@@ -432,7 +482,7 @@ mod test {
         res.put(prepared_stmt);
         res.put_i16(0);
 
-        assert!(qr.infer_role(res));
+        assert!(qr.infer_role_and_shard(res));
         assert_eq!(qr.role(), Some(Role::Replica));
     }
 
@@ -450,6 +500,10 @@ mod test {
             "SET SERVER ROLE TO 'any'",
             "SET SERVER ROLE TO 'auto'",
             "SHOW SERVER ROLE",
+            "SET PRIMARY READS TO 'on'",
+            "SET PRIMARY READS TO 'off'",
+            "SET PRIMARY READS TO 'default'",
+            "SHOW PRIMARY READS",
             // Lower case
             "set sharding key to '1'",
             "set shard to '1'",
@@ -459,9 +513,13 @@ mod test {
             "set server role to 'any'",
             "set server role to 'auto'",
             "show server role",
+            "set primary reads to 'on'",
+            "set primary reads to 'OFF'",
+            "set primary reads to 'deFaUlt'",
             // No quotes
             "SET SHARDING KEY TO 11235",
             "SET SHARD TO 15",
+            "SET PRIMARY READS TO off",
             // Spaces and semicolon
             "  SET SHARDING KEY TO 11235  ; ",
             "  SET SHARD TO 15;   ",
@@ -469,18 +527,23 @@ mod test {
             " SET SERVER ROLE TO 'primary';   ",
             "    SET SERVER ROLE TO 'primary'  ; ",
             "  SET SERVER ROLE TO 'primary'  ;",
+            "  SET PRIMARY READS TO 'off'    ;",
         ];
 
         // Which regexes it'll match to in the list
         let matches = [
-            0, 1, 2, 3, 3, 3, 3, 4, 0, 1, 2, 3, 3, 3, 3, 4, 0, 1, 0, 1, 0, 3, 3, 3,
+            0, 1, 2, 3, 3, 3, 3, 4, 5, 5, 5, 6, 0, 1, 2, 3, 3, 3, 3, 4, 5, 5, 5, 0, 1, 5, 0, 1, 0,
+            3, 3, 3, 5,
         ];
 
         let list = CUSTOM_SQL_REGEX_LIST.get().unwrap();
         let set = CUSTOM_SQL_REGEX_SET.get().unwrap();
 
         for (i, test) in tests.iter().enumerate() {
-            assert!(list[matches[i]].is_match(test));
+            if !list[matches[i]].is_match(test) {
+                println!("{} does not match {}", test, list[matches[i]]);
+                assert!(false);
+            }
             assert_eq!(set.matches(test).into_iter().collect::<Vec<_>>().len(), 1);
         }
 
@@ -503,9 +566,9 @@ mod test {
         let query = simple_query("SET SHARDING KEY TO 13");
         assert_eq!(
             qr.try_execute_command(query),
-            Some((Command::SetShardingKey, String::from("1")))
+            Some((Command::SetShardingKey, String::from("0")))
         );
-        assert_eq!(qr.shard(), 1);
+        assert_eq!(qr.shard(), 0);
 
         // SetShard
         let query = simple_query("SET SHARD TO '1'");
@@ -549,6 +612,26 @@ mod test {
                 Some((Command::ShowServerRole, String::from(*role)))
             );
         }
+
+        let primary_reads = ["on", "off", "default"];
+        let primary_reads_enabled = ["on", "off", "on"];
+
+        for (idx, primary_reads) in primary_reads.iter().enumerate() {
+            assert_eq!(
+                qr.try_execute_command(simple_query(&format!(
+                    "SET PRIMARY READS TO {}",
+                    primary_reads
+                ))),
+                Some((Command::SetPrimaryReads, String::from(*primary_reads)))
+            );
+            assert_eq!(
+                qr.try_execute_command(simple_query("SHOW PRIMARY READS")),
+                Some((
+                    Command::ShowPrimaryReads,
+                    String::from(primary_reads_enabled[idx])
+                ))
+            );
+        }
     }
 
     #[test]
@@ -556,18 +639,18 @@ mod test {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         let query = simple_query("SET SERVER ROLE TO 'auto'");
-        qr.toggle_primary_reads(false);
+        assert!(qr.try_execute_command(simple_query("SET PRIMARY READS TO off")) != None);
 
         assert!(qr.try_execute_command(query) != None);
         assert!(qr.query_parser_enabled());
         assert_eq!(qr.role(), None);
 
         let query = simple_query("INSERT INTO test_table VALUES (1)");
-        assert_eq!(qr.infer_role(query), true);
+        assert_eq!(qr.infer_role_and_shard(query), true);
         assert_eq!(qr.role(), Some(Role::Primary));
 
         let query = simple_query("SELECT * FROM test_table");
-        assert_eq!(qr.infer_role(query), true);
+        assert_eq!(qr.infer_role_and_shard(query), true);
         assert_eq!(qr.role(), Some(Role::Replica));
 
         assert!(qr.query_parser_enabled());
@@ -575,4 +658,41 @@ mod test {
         assert!(qr.try_execute_command(query) != None);
         assert!(!qr.query_parser_enabled());
     }
+
+    #[test]
+    fn test_update_from_pool_settings() {
+        QueryRouter::setup();
+
+        let pool_settings = PoolSettings {
+            pool_mode: PoolMode::Transaction,
+            shards: 0,
+            user: crate::config::User::default(),
+            default_role: Some(Role::Replica),
+            query_parser_enabled: true,
+            primary_reads_enabled: true,
+            sharding_key_regex: None,
+            sharding_function: ShardingFunction::PgBigintHash,
+        };
+        let mut qr = QueryRouter::new();
+        assert_eq!(qr.active_role, None);
+        assert_eq!(qr.active_shard, None);
+        assert_eq!(qr.query_parser_enabled, false);
+        assert_eq!(qr.primary_reads_enabled, false);
+
+        // Internal state must not be changed due to this, only defaults
+        qr.update_pool_settings(pool_settings.clone());
+
+        assert_eq!(qr.active_role, None);
+        assert_eq!(qr.active_shard, None);
+        assert_eq!(qr.query_parser_enabled, true);
+        assert_eq!(qr.primary_reads_enabled, true);
+
+        let q1 = simple_query("SET SERVER ROLE TO 'primary'");
+        assert!(qr.try_execute_command(q1) != None);
+        assert_eq!(qr.active_role.unwrap(), Role::Primary);
+
+        let q2 = simple_query("SET SERVER ROLE TO 'default'");
+        assert!(qr.try_execute_command(q2) != None);
+        assert_eq!(qr.active_role.unwrap(), pool_settings.clone().default_role);
+    }
 }

src/server.rs

@@ -1,7 +1,9 @@
 /// Implementation of the PostgreSQL server (database) protocol.
 /// Here we are pretending to the a Postgres client.
 use bytes::{Buf, BufMut, BytesMut};
-use log::{debug, error, info, trace};
+use log::{debug, error, info, trace, warn};
+use std::io::Read;
+use std::time::SystemTime;
 use tokio::io::{AsyncReadExt, BufReader};
 use tokio::net::{
     tcp::{OwnedReadHalf, OwnedWriteHalf},
@@ -47,6 +49,9 @@ 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,
+
     /// Mapping of clients and servers used for query cancellation.
     client_server_map: ClientServerMap,
 
@@ -58,6 +63,9 @@ 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_activity: SystemTime,
 }
 
 impl Server {
@@ -71,7 +79,7 @@ impl Server {
         stats: Reporter,
     ) -> Result<Server, Error> {
         let mut stream =
-            match TcpStream::connect(&format!("{}:{}", &address.host, &address.port)).await {
+            match TcpStream::connect(&format!("{}:{}", &address.host, address.port)).await {
                 Ok(stream) => stream,
                 Err(err) => {
                     error!("Could not connect to server: {}", err);
@@ -82,7 +90,7 @@ impl Server {
         trace!("Sending StartupMessage");
 
         // StartupMessage
-        startup(&mut stream, &user.name, database).await?;
+        startup(&mut stream, &user.username, database).await?;
 
         let mut server_info = BytesMut::new();
         let mut process_id: i32 = 0;
@@ -127,7 +135,7 @@ impl Server {
                                 Err(_) => return Err(Error::SocketError),
                             };
 
-                            md5_password(&mut stream, &user.name, &user.password, &salt[..])
+                            md5_password(&mut stream, &user.username, &user.password, &salt[..])
                                 .await?;
                         }
 
@@ -312,10 +320,12 @@ impl Server {
                         in_transaction: false,
                         data_available: false,
                         bad: false,
+                        needs_cleanup: false,
                         client_server_map: client_server_map,
                         connected_at: chrono::offset::Utc::now().naive_utc(),
                         stats: stats,
                         application_name: String::new(),
+                        last_activity: SystemTime::now(),
                     };
 
                     server.set_name("pgcat").await?;
@@ -337,7 +347,7 @@ impl Server {
     /// Uses a separate connection that's not part of the connection pool.
     pub async fn cancel(
         host: &str,
-        port: &str,
+        port: u16,
         process_id: i32,
         secret_key: i32,
     ) -> Result<(), Error> {
@@ -366,7 +376,11 @@ impl Server {
             .data_sent(messages.len(), self.process_id, self.address.id);
 
         match write_all_half(&mut self.write, messages).await {
-            Ok(_) => Ok(()),
+            Ok(_) => {
+                // Successfully sent to server
+                self.last_activity = SystemTime::now();
+                Ok(())
+            }
             Err(err) => {
                 error!("Terminating server because of: {:?}", err);
                 self.bad = true;
@@ -413,7 +427,7 @@ impl Server {
                             self.in_transaction = false;
                         }
 
-                        // Some error occured, the transaction was rolled back.
+                        // Some error occurred, the transaction was rolled back.
                         'E' => {
                             self.in_transaction = true;
                         }
@@ -431,6 +445,29 @@ impl Server {
                     break;
                 }
 
+                // CommandComplete
+                'C' => {
+                    let mut command_tag = String::new();
+                    match message.reader().read_to_string(&mut command_tag) {
+                        Ok(_) => {
+                            // Non-exhaustive list of commands that are likely to change session variables/resources
+                            // which can leak between clients. This is a best effort to block bad clients
+                            // from poisoning a transaction-mode pool by setting inappropriate session variables
+                            match command_tag.as_str() {
+                                "SET\0" | "PREPARE\0" => {
+                                    debug!("Server connection marked for clean up");
+                                    self.needs_cleanup = true;
+                                }
+                                _ => (),
+                            }
+                        }
+
+                        Err(err) => {
+                            warn!("Encountered an error while parsing CommandTag {}", err);
+                        }
+                    }
+                }
+
                 // DataRow
                 'D' => {
                     // More data is available after this message, this is not the end of the reply.
@@ -474,6 +511,9 @@ impl Server {
         // Clear the buffer for next query.
         self.buffer.clear();
 
+        // Successfully received data from server
+        self.last_activity = SystemTime::now();
+
         // Pass the data back to the client.
         Ok(bytes)
     }
@@ -517,7 +557,7 @@ impl Server {
                 self.process_id,
                 self.secret_key,
                 self.address.host.clone(),
-                self.address.port.clone(),
+                self.address.port,
             ),
         );
     }
@@ -541,14 +581,43 @@ impl Server {
         Ok(())
     }
 
+    /// Perform any necessary cleanup before putting the server
+    /// connection back in the pool
+    pub async fn checkin_cleanup(&mut self) -> Result<(), Error> {
+        // Client disconnected with an open transaction on the server connection.
+        // Pgbouncer behavior is to close the server connection but that can cause
+        // server connection thrashing if clients repeatedly do this.
+        // Instead, we ROLLBACK that transaction before putting the connection back in the pool
+        if self.in_transaction() {
+            self.query("ROLLBACK").await?;
+        }
+
+        // Client disconnected but it perfromed session-altering operations such as
+        // SET statement_timeout to 1 or create a prepared statement. We clear that
+        // 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 {
+            self.query("DISCARD ALL").await?;
+            self.needs_cleanup = false;
+        }
+
+        return Ok(());
+    }
+
     /// A shorthand for `SET application_name = $1`.
-    #[allow(dead_code)]
     pub async fn set_name(&mut self, name: &str) -> Result<(), Error> {
         if self.application_name != name {
             self.application_name = name.to_string();
-            Ok(self
+            // We don't want `SET application_name` to mark the server connection
+            // as needing cleanup
+            let needs_cleanup_before = self.needs_cleanup;
+
+            let result = Ok(self
                 .query(&format!("SET application_name = '{}'", name))
-                .await?)
+                .await?);
+            self.needs_cleanup = needs_cleanup_before;
+            return result;
         } else {
             Ok(())
         }
@@ -564,6 +633,16 @@ impl Server {
     pub fn process_id(&self) -> i32 {
         self.process_id
     }
+
+    // Get server's latest response timestamp
+    pub fn last_activity(&self) -> SystemTime {
+        self.last_activity
+    }
+
+    // Marks a connection as needing DISCARD ALL at checkin
+    pub fn mark_dirty(&mut self) {
+        self.needs_cleanup = true;
+    }
 }
 
 impl Drop for Server {
@@ -590,7 +669,8 @@ impl Drop for Server {
         let duration = now - self.connected_at;
 
         info!(
-            "Server connection closed, session duration: {}",
+            "Server connection closed {:?}, session duration: {}",
+            self.address,
             crate::format_duration(&duration)
         );
     }

src/stats.rs

@@ -1,9 +1,16 @@
+use arc_swap::ArcSwap;
 /// Statistics and reporting.
-use log::info;
+use log::{error, info, trace};
 use once_cell::sync::Lazy;
 use parking_lot::Mutex;
 use std::collections::HashMap;
-use tokio::sync::mpsc::{Receiver, Sender};
+use tokio::sync::mpsc::error::TrySendError;
+use tokio::sync::mpsc::{channel, Receiver, Sender};
+
+use crate::pool::get_number_of_addresses;
+
+pub static REPORTER: Lazy<ArcSwap<Reporter>> =
+    Lazy::new(|| ArcSwap::from_pointee(Reporter::default()));
 
 /// Latest stats updated every second; used in SHOW STATS and other admin commands.
 static LATEST_STATS: Lazy<Mutex<HashMap<usize, HashMap<String, i64>>>> =
@@ -37,7 +44,7 @@ enum EventName {
 
 /// Event data sent to the collector
 /// from clients and servers.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct Event {
     /// The name of the event being reported.
     name: EventName,
@@ -60,12 +67,38 @@ pub struct Reporter {
     tx: Sender<Event>,
 }
 
+impl Default for Reporter {
+    fn default() -> Reporter {
+        let (tx, _rx) = channel(5);
+        Reporter { tx }
+    }
+}
+
 impl Reporter {
     /// Create a new Reporter instance.
     pub fn new(tx: Sender<Event>) -> Reporter {
         Reporter { tx: tx }
     }
 
+    /// Send statistics to the task keeping track of stats.
+    fn send(&self, event: Event) {
+        let name = event.name;
+        let result = self.tx.try_send(event);
+
+        match result {
+            Ok(_) => trace!(
+                "{:?} event reported successfully, capacity: {}",
+                name,
+                self.tx.capacity()
+            ),
+
+            Err(err) => match err {
+                TrySendError::Full { .. } => error!("{:?} event dropped, buffer full", name),
+                TrySendError::Closed { .. } => error!("{:?} event dropped, channel closed", name),
+            },
+        };
+    }
+
     /// Report a query executed by a client against
     /// a server identified by the `address_id`.
     pub fn query(&self, process_id: i32, address_id: usize) {
@@ -76,7 +109,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event);
     }
 
     /// Report a transaction executed by a client against
@@ -89,7 +122,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Report data sent to a server identified by `address_id`.
@@ -102,7 +135,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Report data received from a server identified by `address_id`.
@@ -115,7 +148,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Time spent waiting to get a healthy connection from the pool
@@ -129,7 +162,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a client identified by `process_id` waiting for a connection
@@ -142,7 +175,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a client identified by `process_id` is done waiting for a connection
@@ -155,7 +188,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a client identified by `process_id` is done querying the server
@@ -168,7 +201,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a client identified by `process_id` is disconecting from the pooler.
@@ -181,7 +214,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a server connection identified by `process_id` for
@@ -195,7 +228,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a server connection identified by `process_id` for
@@ -209,7 +242,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a server connection identified by `process_id` for
@@ -223,7 +256,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a server connection identified by `process_id` for
@@ -237,7 +270,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 
     /// Reports a server connection identified by `process_id` is disconecting from the pooler.
@@ -250,7 +283,7 @@ impl Reporter {
             address_id: address_id,
         };
 
-        let _ = self.tx.try_send(event);
+        self.send(event)
     }
 }
 
@@ -274,22 +307,23 @@ impl Collector {
 
     /// The statistics collection handler. It will collect statistics
     /// for `address_id`s starting at 0 up to `addresses`.
-    pub async fn collect(&mut self, addresses: usize) {
+    pub async fn collect(&mut self) {
         info!("Events reporter started");
 
         let stats_template = HashMap::from([
             ("total_query_count", 0),
-            ("total_xact_count", 0),
-            ("total_sent", 0),
-            ("total_received", 0),
-            ("total_xact_time", 0),
             ("total_query_time", 0),
+            ("total_received", 0),
+            ("total_sent", 0),
+            ("total_xact_count", 0),
+            ("total_xact_time", 0),
             ("total_wait_time", 0),
-            ("avg_xact_time", 0),
+            ("avg_query_count", 0),
             ("avg_query_time", 0),
-            ("avg_xact_count", 0),
+            ("avg_recv", 0),
             ("avg_sent", 0),
-            ("avg_received", 0),
+            ("avg_xact_count", 0),
+            ("avg_xact_time", 0),
             ("avg_wait_time", 0),
             ("maxwait_us", 0),
             ("maxwait", 0),
@@ -318,7 +352,8 @@ impl Collector {
                 tokio::time::interval(tokio::time::Duration::from_millis(STAT_PERIOD / 15));
             loop {
                 interval.tick().await;
-                for address_id in 0..addresses {
+                let address_count = get_number_of_addresses();
+                for address_id in 0..address_count {
                     let _ = tx.try_send(Event {
                         name: EventName::UpdateStats,
                         value: 0,
@@ -335,7 +370,8 @@ impl Collector {
                 tokio::time::interval(tokio::time::Duration::from_millis(STAT_PERIOD));
             loop {
                 interval.tick().await;
-                for address_id in 0..addresses {
+                let address_count = get_number_of_addresses();
+                for address_id in 0..address_count {
                     let _ = tx.try_send(Event {
                         name: EventName::UpdateAverages,
                         value: 0,
@@ -491,12 +527,18 @@ impl Collector {
                     // Calculate averages
                     for stat in &[
                         "avg_query_count",
-                        "avgxact_count",
+                        "avg_query_time",
+                        "avg_recv",
                         "avg_sent",
-                        "avg_received",
+                        "avg_xact_time",
+                        "avg_xact_count",
                         "avg_wait_time",
                     ] {
-                        let total_name = stat.replace("avg_", "total_");
+                        let total_name = match stat {
+                            &"avg_recv" => "total_received".to_string(), // Because PgBouncer is saving bytes
+                            _ => stat.replace("avg_", "total_"),
+                        };
+
                         let old_value = old_stats.entry(total_name.clone()).or_insert(0);
                         let new_value = stats.get(total_name.as_str()).unwrap_or(&0).to_owned();
                         let avg = (new_value - *old_value) / (STAT_PERIOD as i64 / 1_000); // Avg / second
@@ -515,3 +557,8 @@ impl Collector {
 pub fn get_stats() -> HashMap<usize, HashMap<String, i64>> {
     LATEST_STATS.lock().clone()
 }
+
+/// Get the statistics reporter used to update stats across the pools/clients.
+pub fn get_reporter() -> Reporter {
+    (*(*REPORTER.load())).clone()
+}

src/tls.rs

@@ -0,0 +1,57 @@
+// Stream wrapper.
+
+use rustls_pemfile::{certs, rsa_private_keys};
+use std::path::Path;
+use std::sync::Arc;
+use tokio_rustls::rustls::{self, Certificate, PrivateKey};
+use tokio_rustls::TlsAcceptor;
+
+use crate::config::get_config;
+use crate::errors::Error;
+
+// TLS
+pub fn load_certs(path: &Path) -> std::io::Result<Vec<Certificate>> {
+    certs(&mut std::io::BufReader::new(std::fs::File::open(path)?))
+        .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidInput, "invalid cert"))
+        .map(|mut certs| certs.drain(..).map(Certificate).collect())
+}
+
+pub fn load_keys(path: &Path) -> std::io::Result<Vec<PrivateKey>> {
+    rsa_private_keys(&mut std::io::BufReader::new(std::fs::File::open(path)?))
+        .map_err(|_| std::io::Error::new(std::io::ErrorKind::InvalidInput, "invalid key"))
+        .map(|mut keys| keys.drain(..).map(PrivateKey).collect())
+}
+
+pub struct Tls {
+    pub acceptor: TlsAcceptor,
+}
+
+impl Tls {
+    pub fn new() -> Result<Self, Error> {
+        let config = get_config();
+
+        let certs = match load_certs(&Path::new(&config.general.tls_certificate.unwrap())) {
+            Ok(certs) => certs,
+            Err(_) => return Err(Error::TlsError),
+        };
+
+        let mut keys = match load_keys(&Path::new(&config.general.tls_private_key.unwrap())) {
+            Ok(keys) => keys,
+            Err(_) => return Err(Error::TlsError),
+        };
+
+        let config = match rustls::ServerConfig::builder()
+            .with_safe_defaults()
+            .with_no_client_auth()
+            .with_single_cert(certs, keys.remove(0))
+            .map_err(|err| std::io::Error::new(std::io::ErrorKind::InvalidInput, err))
+        {
+            Ok(c) => c,
+            Err(_) => return Err(Error::TlsError),
+        };
+
+        Ok(Tls {
+            acceptor: TlsAcceptor::from(Arc::new(config)),
+        })
+    }
+}

tests/docker/Dockerfile

@@ -0,0 +1,5 @@
+FROM rust:bullseye
+
+RUN apt-get update && apt-get install llvm-11 psmisc postgresql-contrib postgresql-client ruby ruby-dev libpq-dev python3 python3-pip lcov sudo curl -y
+RUN cargo install cargo-binutils rustfilt
+RUN rustup component add llvm-tools-preview

tests/docker/docker-compose.yml

@@ -0,0 +1,47 @@
+version: "3"
+services:
+  pg1:
+    image: postgres:14
+    network_mode: "service:main"
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+    command: ["postgres", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-p", "5432"]
+  pg2:
+    image: postgres:14
+    network_mode: "service:main"
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+    command: ["postgres", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-p", "7432"]
+  pg3:
+    image: postgres:14
+    network_mode: "service:main"
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+    command: ["postgres", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-p", "8432"]
+  pg4:
+    image: postgres:14
+    network_mode: "service:main"
+    environment:
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_HOST_AUTH_METHOD: scram-sha-256
+    command: ["postgres", "-c", "shared_preload_libraries=pg_stat_statements", "-c", "pg_stat_statements.track=all", "-p", "9432"]
+  main:
+    build: .
+    command: ["bash", "/app/tests/docker/run.sh"]
+    environment:
+      RUSTFLAGS: "-C instrument-coverage"
+      LLVM_PROFILE_FILE: "pgcat-%m.profraw"
+    volumes:
+      - ../../:/app/
+      - /app/target/

tests/docker/run.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+rm /app/*.profraw || true
+rm /app/pgcat.profdata || true
+rm -rf /app/cov || true
+
+cd /app/
+
+cargo build
+cargo test --tests
+
+bash .circleci/run_tests.sh
+
+rust-profdata merge -sparse pgcat-*.profraw -o pgcat.profdata
+
+rust-cov export -ignore-filename-regex="rustc|registry" -Xdemangler=rustfilt -instr-profile=pgcat.profdata --object ./target/debug/pgcat --format lcov > ./lcov.info
+
+genhtml lcov.info --output-directory cov --prefix $(pwd)
+
+rm /app/*.profraw
+rm /app/pgcat.profdata

tests/pgbench/simple.sql

@@ -12,6 +12,8 @@
 
 SET SHARD TO :shard;
 
+SET SERVER ROLE TO 'auto';
+
 BEGIN;
 
 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;
@@ -26,3 +28,12 @@ INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :a
 
 END;
 
+SET SHARDING KEY TO :aid;
+
+-- Read load balancing
+SELECT abalance FROM pgbench_accounts WHERE aid = :aid;
+
+SET SERVER ROLE TO 'replica';
+
+-- Read load balancing
+SELECT abalance FROM pgbench_accounts WHERE aid = :aid;

tests/python/requirements.txt

@@ -1 +1,2 @@
 psycopg2==2.9.3
+psutil==5.9.1

tests/python/tests.py

@@ -1,11 +1,257 @@
+from typing import Tuple
 import psycopg2
+import psutil
+import os
+import signal
+import time
 
-conn = psycopg2.connect("postgres://random:password@127.0.0.1:6432/db")
-cur = conn.cursor()
+SHUTDOWN_TIMEOUT = 5
 
-cur.execute("SELECT 1");
-res = cur.fetchall()
+PGCAT_HOST = "127.0.0.1"
+PGCAT_PORT = "6432"
 
-print(res)
 
-# conn.commit()
+def pgcat_start():
+    pg_cat_send_signal(signal.SIGTERM)
+    os.system("./target/debug/pgcat .circleci/pgcat.toml &")
+    time.sleep(2)
+
+
+def pg_cat_send_signal(signal: signal.Signals):
+    try:
+        for proc in psutil.process_iter(["pid", "name"]):
+            if "pgcat" == proc.name():
+                os.kill(proc.pid, signal)
+    except Exception as e:
+        # The process can be gone when we send this signal
+        print(e)
+
+    if signal == signal.SIGTERM:
+        # Returns 0 if pgcat process exists
+        time.sleep(2)
+        if not os.system('pgrep pgcat'):
+            raise Exception("pgcat not closed after SIGTERM")
+
+
+def connect_db(
+    autocommit: bool = True,
+    admin: bool = False,
+) -> Tuple[psycopg2.extensions.connection, psycopg2.extensions.cursor]:
+
+    if admin:
+        user = "admin_user"
+        password = "admin_pass"
+        db = "pgcat"
+    else:
+        user = "sharding_user"
+        password = "sharding_user"
+        db = "sharded_db"
+
+    conn = psycopg2.connect(
+        f"postgres://{user}:{password}@{PGCAT_HOST}:{PGCAT_PORT}/{db}?application_name=testing_pgcat",
+        connect_timeout=2,
+    )
+    conn.autocommit = autocommit
+    cur = conn.cursor()
+
+    return (conn, cur)
+
+
+def cleanup_conn(conn: psycopg2.extensions.connection, cur: psycopg2.extensions.cursor):
+    cur.close()
+    conn.close()
+
+
+def test_normal_db_access():
+    conn, cur = connect_db(autocommit=False)
+    cur.execute("SELECT 1")
+    res = cur.fetchall()
+    print(res)
+    cleanup_conn(conn, cur)
+
+
+def test_admin_db_access():
+    conn, cur = connect_db(admin=True)
+
+    cur.execute("SHOW POOLS")
+    res = cur.fetchall()
+    print(res)
+    cleanup_conn(conn, cur)
+
+
+def test_shutdown_logic():
+
+    # - - - - - - - - - - - - - - - - - -
+    # NO ACTIVE QUERIES SIGINT HANDLING
+
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and send query (not in transaction)
+    conn, cur = connect_db()
+
+    cur.execute("BEGIN;")
+    cur.execute("SELECT 1;")
+    cur.execute("COMMIT;")
+
+    # Send sigint to pgcat
+    pg_cat_send_signal(signal.SIGINT)
+    time.sleep(1)
+
+    # Check that any new queries fail after sigint since server should close with no active transactions
+    try:
+        cur.execute("SELECT 1;")
+    except psycopg2.OperationalError as e:
+        pass
+    else:
+        # Fail if query execution succeeded
+        raise Exception("Server not closed after sigint")
+
+    cleanup_conn(conn, cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+    # HANDLE TRANSACTION WITH SIGINT
+
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and begin transaction
+    conn, cur = connect_db()
+
+    cur.execute("BEGIN;")
+    cur.execute("SELECT 1;")
+
+    # Send sigint to pgcat while still in transaction
+    pg_cat_send_signal(signal.SIGINT)
+    time.sleep(1)
+
+    # Check that any new queries succeed after sigint since server should still allow transaction to complete
+    try:
+        cur.execute("SELECT 1;")
+    except psycopg2.OperationalError as e:
+        # Fail if query fails since server closed
+        raise Exception("Server closed while in transaction", e.pgerror)
+
+    cleanup_conn(conn, cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+    # NO NEW NON-ADMIN CONNECTIONS DURING SHUTDOWN
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and begin transaction
+    transaction_conn, transaction_cur = connect_db()
+
+    transaction_cur.execute("BEGIN;")
+    transaction_cur.execute("SELECT 1;")
+
+    # Send sigint to pgcat while still in transaction
+    pg_cat_send_signal(signal.SIGINT)
+    time.sleep(1)
+
+    start = time.perf_counter()
+    try:
+        conn, cur = connect_db()
+        cur.execute("SELECT 1;")
+        cleanup_conn(conn, cur)
+    except psycopg2.OperationalError as e:
+        time_taken = time.perf_counter() - start
+        if time_taken > 0.1:
+            raise Exception(
+                "Failed to reject connection within 0.1 seconds, got", time_taken, "seconds")
+        pass
+    else:
+        raise Exception("Able connect to database during shutdown")
+
+    cleanup_conn(transaction_conn, transaction_cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+    # ALLOW NEW ADMIN CONNECTIONS DURING SHUTDOWN
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and begin transaction
+    transaction_conn, transaction_cur = connect_db()
+
+    transaction_cur.execute("BEGIN;")
+    transaction_cur.execute("SELECT 1;")
+
+    # Send sigint to pgcat while still in transaction
+    pg_cat_send_signal(signal.SIGINT)
+    time.sleep(1)
+
+    try:
+        conn, cur = connect_db(admin=True)
+        cur.execute("SHOW DATABASES;")
+        cleanup_conn(conn, cur)
+    except psycopg2.OperationalError as e:
+        raise Exception(e)
+
+    cleanup_conn(transaction_conn, transaction_cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+    # ADMIN CONNECTIONS CONTINUING TO WORK AFTER SHUTDOWN
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and begin transaction
+    transaction_conn, transaction_cur = connect_db()
+    transaction_cur.execute("BEGIN;")
+    transaction_cur.execute("SELECT 1;")
+
+    admin_conn, admin_cur = connect_db(admin=True)
+    admin_cur.execute("SHOW DATABASES;")
+
+    # Send sigint to pgcat while still in transaction
+    pg_cat_send_signal(signal.SIGINT)
+    time.sleep(1)
+
+    try:
+        admin_cur.execute("SHOW DATABASES;")
+    except psycopg2.OperationalError as e:
+        raise Exception("Could not execute admin command:", e)
+
+    cleanup_conn(transaction_conn, transaction_cur)
+    cleanup_conn(admin_conn, admin_cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+    # HANDLE SHUTDOWN TIMEOUT WITH SIGINT
+
+    # Start pgcat
+    pgcat_start()
+
+    # Create client connection and begin transaction, which should prevent server shutdown unless shutdown timeout is reached
+    conn, cur = connect_db()
+
+    cur.execute("BEGIN;")
+    cur.execute("SELECT 1;")
+
+    # Send sigint to pgcat while still in transaction
+    pg_cat_send_signal(signal.SIGINT)
+
+    # pgcat shutdown timeout is set to SHUTDOWN_TIMEOUT seconds, so we sleep for SHUTDOWN_TIMEOUT + 1 seconds
+    time.sleep(SHUTDOWN_TIMEOUT + 1)
+
+    # Check that any new queries succeed after sigint since server should still allow transaction to complete
+    try:
+        cur.execute("SELECT 1;")
+    except psycopg2.OperationalError as e:
+        pass
+    else:
+        # Fail if query execution succeeded
+        raise Exception("Server not closed after sigint and expected timeout")
+
+    cleanup_conn(conn, cur)
+    pg_cat_send_signal(signal.SIGTERM)
+
+    # - - - - - - - - - - - - - - - - - -
+
+
+test_normal_db_access()
+test_admin_db_access()
+test_shutdown_logic()

tests/ruby/.ruby-version

@@ -1 +1,2 @@
-2.7.1
+3.0.0
+

tests/ruby/Gemfile

@@ -1,5 +1,8 @@
 source "https://rubygems.org"
 
 gem "pg"
-gem "activerecord"
+gem "toml"
+gem "rspec"
 gem "rubocop"
+gem "toxiproxy"
+gem "activerecord"

tests/ruby/Gemfile.lock

@@ -1,28 +1,43 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activemodel (7.0.2.2)
-      activesupport (= 7.0.2.2)
-    activerecord (7.0.2.2)
-      activemodel (= 7.0.2.2)
-      activesupport (= 7.0.2.2)
-    activesupport (7.0.2.2)
+    activemodel (7.0.3.1)
+      activesupport (= 7.0.3.1)
+    activerecord (7.0.3.1)
+      activemodel (= 7.0.3.1)
+      activesupport (= 7.0.3.1)
+    activesupport (7.0.3.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
     ast (2.4.2)
-    concurrent-ruby (1.1.9)
-    i18n (1.10.0)
+    concurrent-ruby (1.1.10)
+    diff-lcs (1.5.0)
+    i18n (1.11.0)
       concurrent-ruby (~> 1.0)
-    minitest (5.15.0)
+    minitest (5.16.2)
     parallel (1.22.1)
     parser (3.1.2.0)
       ast (~> 2.4.1)
+    parslet (2.0.0)
     pg (1.3.2)
     rainbow (3.1.1)
     regexp_parser (2.3.1)
     rexml (3.2.5)
+    rspec (3.11.0)
+      rspec-core (~> 3.11.0)
+      rspec-expectations (~> 3.11.0)
+      rspec-mocks (~> 3.11.0)
+    rspec-core (3.11.0)
+      rspec-support (~> 3.11.0)
+    rspec-expectations (3.11.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.11.0)
+    rspec-mocks (3.11.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.11.0)
+    rspec-support (3.11.0)
     rubocop (1.29.0)
       parallel (~> 1.10)
       parser (>= 3.1.0.0)
@@ -35,17 +50,25 @@ GEM
     rubocop-ast (1.17.0)
       parser (>= 3.1.1.0)
     ruby-progressbar (1.11.0)
+    toml (0.3.0)
+      parslet (>= 1.8.0, < 3.0.0)
+    toxiproxy (2.0.1)
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
     unicode-display_width (2.1.0)
 
 PLATFORMS
+  aarch64-linux
+  arm64-darwin-21
   x86_64-linux
 
 DEPENDENCIES
   activerecord
   pg
+  rspec
   rubocop
+  toml
+  toxiproxy
 
 BUNDLED WITH
-   2.3.7
+   2.3.21

tests/ruby/helpers/pg_instance.rb

@@ -0,0 +1,82 @@
+require 'pg'
+require 'toxiproxy'
+
+class PgInstance
+  attr_reader :port
+  attr_reader :username
+  attr_reader :password
+  attr_reader :database_name
+
+  def initialize(port, username, password, database_name)
+    @original_port = port
+    @toxiproxy_port = 10000 + port.to_i
+    @port = @toxiproxy_port
+
+    @username = username
+    @password = password
+    @database_name = database_name
+    @toxiproxy_name = "database_#{@original_port}"
+    Toxiproxy.populate([{
+      name: @toxiproxy_name,
+      listen: "0.0.0.0:#{@toxiproxy_port}",
+      upstream: "localhost:#{@original_port}",
+    }])
+
+    # Toxiproxy server will outlive our PgInstance objects
+    # so we want to destroy our proxies before exiting
+    # Ruby finalizer is ideal for doing this
+    ObjectSpace.define_finalizer(@toxiproxy_name, proc { Toxiproxy[@toxiproxy_name].destroy })
+  end
+
+  def with_connection
+    conn = PG.connect("postgres://#{@username}:#{@password}@localhost:#{port}/#{database_name}")
+    yield conn
+  ensure
+    conn&.close
+  end
+
+  def reset
+    reset_toxics
+    reset_stats
+  end
+
+  def toxiproxy
+    Toxiproxy[@toxiproxy_name]
+  end
+
+  def take_down
+    if block_given?
+      Toxiproxy[@toxiproxy_name].toxic(:limit_data, bytes: 5).apply { yield }
+    else
+      Toxiproxy[@toxiproxy_name].toxic(:limit_data, bytes: 5).toxics.each(&:save)
+    end
+  end
+
+  def add_latency(latency)
+    if block_given?
+      Toxiproxy[@toxiproxy_name].toxic(:latency, latency: latency).apply { yield }
+    else
+      Toxiproxy[@toxiproxy_name].toxic(:latency, latency: latency).toxics.each(&:save)
+    end
+  end
+
+  def delete_proxy
+    Toxiproxy[@toxiproxy_name].delete
+  end
+
+  def reset_toxics
+    Toxiproxy[@toxiproxy_name].toxics.each(&:destroy)
+  end
+
+  def reset_stats
+    with_connection { |c| c.async_exec("SELECT pg_stat_statements_reset()") }
+  end
+
+  def count_query(query)
+    with_connection { |c| c.async_exec("SELECT SUM(calls) FROM pg_stat_statements WHERE query = '#{query}'")[0]["sum"].to_i }
+  end
+
+  def count_select_1_plus_2
+    with_connection { |c| c.async_exec("SELECT SUM(calls) FROM pg_stat_statements WHERE query = 'SELECT $1 + $2'")[0]["sum"].to_i }
+  end
+end

tests/ruby/helpers/pgcat_helper.rb

@@ -0,0 +1,100 @@
+require 'json'
+require 'ostruct'
+require_relative 'pgcat_process'
+require_relative 'pg_instance'
+
+module Helpers
+  module Pgcat
+    def self.three_shard_setup(pool_name, pool_size, pool_mode="transaction")
+      user = {
+        "password" => "sharding_user",
+        "pool_size" => pool_size,
+        "statement_timeout" => 0,
+        "username" => "sharding_user"
+      }
+
+      pgcat    = PgcatProcess.new("info")
+      primary0 = PgInstance.new(5432, user["username"], user["password"], "shard0")
+      primary1 = PgInstance.new(7432, user["username"], user["password"], "shard1")
+      primary2 = PgInstance.new(8432, user["username"], user["password"], "shard2")
+
+      pgcat_cfg = pgcat.current_config
+      pgcat_cfg["pools"] = {
+        "#{pool_name}" => {
+          "default_role" => "any",
+          "pool_mode" => pool_mode,
+          "primary_reads_enabled" => false,
+          "query_parser_enabled" => false,
+          "sharding_function" => "pg_bigint_hash",
+          "shards" => {
+            "0" => { "database" => "shard0", "servers" => [["localhost", primary0.port.to_s, "primary"]] },
+            "1" => { "database" => "shard1", "servers" => [["localhost", primary1.port.to_s, "primary"]] },
+            "2" => { "database" => "shard2", "servers" => [["localhost", primary2.port.to_s, "primary"]] },
+          },
+          "users" => { "0" => user }
+        }
+      }
+      pgcat.update_config(pgcat_cfg)
+
+      pgcat.start
+      pgcat.wait_until_ready
+
+      OpenStruct.new.tap do |struct|
+        struct.pgcat = pgcat
+        struct.shards = [primary0, primary1, primary2]
+        struct.all_databases = [primary0, primary1, primary2]
+      end
+    end
+
+    def self.single_shard_setup(pool_name, pool_size, pool_mode="transaction")
+      user = {
+        "password" => "sharding_user",
+        "pool_size" => pool_size,
+        "statement_timeout" => 0,
+        "username" => "sharding_user"
+      }
+
+      pgcat = PgcatProcess.new("info")
+      pgcat_cfg = pgcat.current_config
+
+      primary  = PgInstance.new(5432, user["username"], user["password"], "shard0")
+      replica0 = PgInstance.new(7432, user["username"], user["password"], "shard0")
+      replica1 = PgInstance.new(8432, user["username"], user["password"], "shard0")
+      replica2 = PgInstance.new(9432, user["username"], user["password"], "shard0")
+
+      # Main proxy configs
+      pgcat_cfg["pools"] = {
+        "#{pool_name}" => {
+          "default_role" => "any",
+          "pool_mode" => pool_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 }
+        }
+      }
+      pgcat_cfg["general"]["port"] = pgcat.port
+      pgcat.update_config(pgcat_cfg)
+      pgcat.start
+      pgcat.wait_until_ready
+
+      OpenStruct.new.tap do |struct|
+        struct.pgcat = pgcat
+        struct.primary = primary
+        struct.replicas = [replica0, replica1, replica2]
+        struct.all_databases = [primary, replica0, replica1, replica2]
+      end
+    end
+  end
+end

tests/ruby/helpers/pgcat_process.rb

@@ -0,0 +1,116 @@
+require 'pg'
+require 'toml'
+require 'fileutils'
+require 'securerandom'
+
+class PgcatProcess
+  attr_reader :port
+  attr_reader :pid
+
+  def self.finalize(pid, log_filename, config_filename)
+    `kill #{pid}`
+    File.delete(config_filename) if File.exist?(config_filename)
+    File.delete(log_filename) if File.exist?(log_filename)
+  end
+
+  def initialize(log_level)
+    @env = {"RUST_LOG" => log_level}
+    @port = rand(20000..32760)
+    @log_level = log_level
+    @log_filename = "/tmp/pgcat_log_#{SecureRandom.urlsafe_base64}.log"
+    @config_filename = "/tmp/pgcat_cfg_#{SecureRandom.urlsafe_base64}.toml"
+
+    @command = "../../target/debug/pgcat #{@config_filename}"
+
+    FileUtils.cp("../../pgcat.toml", @config_filename)
+    cfg = current_config
+    cfg["general"]["port"] = @port.to_i
+    cfg["general"]["enable_prometheus_exporter"] = false
+
+    update_config(cfg)
+  end
+
+  def logs
+    File.read(@log_filename)
+  end
+
+  def update_config(config_hash)
+    @original_config = current_config
+    output_to_write = TOML::Generator.new(config_hash).body
+    output_to_write = output_to_write.gsub(/,\s*["|'](\d+)["|']\s*,/, ',\1,')
+    File.write(@config_filename, output_to_write)
+  end
+
+  def current_config
+    old_cfg = File.read(@config_filename)
+    loadable_string = old_cfg.gsub(/,\s*(\d+)\s*,/, ', "\1",')
+    TOML.load(loadable_string)
+  end
+
+  def reload_config
+    `kill -s HUP #{@pid}`
+    sleep 0.1
+  end
+
+  def start
+    raise StandardError, "Process is already started" unless @pid.nil?
+    @pid = Process.spawn(@env, @command, err: @log_filename, out: @log_filename)
+    ObjectSpace.define_finalizer(@log_filename, proc { PgcatProcess.finalize(@pid, @log_filename, @config_filename) })
+
+    return self
+  end
+
+  def wait_until_ready
+    exc = nil
+    10.times do
+      PG::connect(example_connection_string).close
+
+      return self
+    rescue => e
+      exc = e
+      sleep(0.5)
+    end
+    puts exc
+    raise StandardError, "Process #{@pid} never became ready. Logs #{logs}"
+  end
+
+  def stop
+    `kill #{@pid}`
+    sleep 0.1
+  end
+
+  def shutdown
+    stop
+    File.delete(@config_filename) if File.exist?(@config_filename)
+    File.delete(@log_filename) if File.exist?(@log_filename)
+  end
+
+  def admin_connection_string
+    cfg = current_config
+    username = cfg["general"]["admin_username"]
+    password = cfg["general"]["admin_password"]
+
+    "postgresql://#{username}:#{password}@0.0.0.0:#{@port}/pgcat"
+  end
+
+  def connection_string(pool_name, username)
+    cfg = current_config
+
+    user_idx, user_obj = cfg["pools"][pool_name]["users"].detect { |k, user| user["username"] == username }
+    password = user_obj["password"]
+
+    "postgresql://#{username}:#{password}@0.0.0.0:#{@port}/#{pool_name}"
+  end
+
+  def example_connection_string
+    cfg = current_config
+    first_pool_name = cfg["pools"].keys[0]
+
+    db_name = first_pool_name
+
+    username = cfg["pools"][first_pool_name]["users"]["0"]["username"]
+    password = cfg["pools"][first_pool_name]["users"]["0"]["password"]
+
+    "postgresql://#{username}:#{password}@0.0.0.0:#{@port}/#{db_name}"
+  end
+end

tests/ruby/load_balancing_spec.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+require_relative 'spec_helper'
+
+describe "Load Balancing" do
+  let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5) }
+  after do
+    processes.all_databases.map(&:reset)
+    processes.pgcat.shutdown
+  end
+
+  context "under regular circumstances" do
+    it "balances query volume between all instances" do
+      conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+
+      query_count = QUERY_COUNT
+      expected_share = query_count / processes.all_databases.count
+      failed_count = 0
+
+      query_count.times do
+        conn.async_exec("SELECT 1 + 2")
+      rescue
+        failed_count += 1
+      end
+
+      expect(failed_count).to eq(0)
+      processes.all_databases.map(&:count_select_1_plus_2).each do |instance_share|
+        expect(instance_share).to be_within(expected_share * MARGIN_OF_ERROR).of(expected_share)
+      end
+    end
+  end
+
+  context "when some replicas are down" do
+    it "balances query volume between working instances" do
+      conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      expected_share = QUERY_COUNT / (processes.all_databases.count - 2)
+      failed_count = 0
+
+      processes[:replicas][0].take_down do
+        processes[:replicas][1].take_down do
+          QUERY_COUNT.times do
+            conn.async_exec("SELECT 1 + 2")
+          rescue
+            conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+            failed_count += 1
+          end
+        end
+      end
+
+      expect(failed_count).to eq(2)
+      processes.all_databases.each do |instance|
+        queries_routed = instance.count_select_1_plus_2
+        if processes.replicas[0..1].include?(instance)
+          expect(queries_routed).to eq(0)
+        else
+          expect(queries_routed).to be_within(expected_share * MARGIN_OF_ERROR).of(expected_share)
+        end
+      end
+    end
+  end
+end
+

tests/ruby/misc_spec.rb

@@ -0,0 +1,193 @@
+# frozen_string_literal: true
+require_relative 'spec_helper'
+
+describe "Miscellaneous" do
+  let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5) }
+  after do
+    processes.all_databases.map(&:reset)
+    processes.pgcat.shutdown
+  end
+
+  describe "Extended Protocol handling" do
+    it "does not send packets that client does not expect during extended protocol sequence" 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
+
+      25.times do
+        Thread.new do
+          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+          conn.async_exec("SELECT pg_sleep(5)") rescue PG::SystemError
+        ensure
+          conn&.close
+        end
+      end
+
+      sleep(0.5)
+      conn_under_test = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      stdout, stderr = with_captured_stdout_stderr do
+        15.times do |i|
+          conn_under_test.async_exec("SELECT 1") rescue PG::SystemError
+          conn_under_test.exec_params("SELECT #{i} + $1", [i]) rescue PG::SystemError
+          sleep 1
+        end
+      end
+
+      raise StandardError, "Libpq got unexpected messages while idle" if stderr.include?("arrived from server while idle")
+    end
+  end
+
+  describe "Pool recycling after config reload" do
+    let(:processes) { Helpers::Pgcat.three_shard_setup("sharded_db", 5) }
+
+    it "should update pools for new clients and clients that are no longer in transaction" do
+      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      server_conn.async_exec("BEGIN")
+
+      # No config change yet, client should set old configs
+      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
+      expect(current_datebase_from_pg).to eq('shard0')
+
+      # Swap shards
+      new_config = processes.pgcat.current_config
+      shard0 = new_config["pools"]["sharded_db"]["shards"]["0"]
+      shard1 = new_config["pools"]["sharded_db"]["shards"]["1"]
+      new_config["pools"]["sharded_db"]["shards"]["0"] = shard1
+      new_config["pools"]["sharded_db"]["shards"]["1"] = shard0
+
+      # Reload config
+      processes.pgcat.update_config(new_config)
+      processes.pgcat.reload_config
+      sleep 0.5
+
+      # Config changed but transaction is in progress, client should set old configs
+      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
+      expect(current_datebase_from_pg).to eq('shard0')
+      server_conn.async_exec("COMMIT")
+
+      # Transaction finished, client should get new configs
+      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
+      expect(current_datebase_from_pg).to eq('shard1')
+
+      # New connection should get new configs
+      server_conn.close()
+      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      current_datebase_from_pg = server_conn.async_exec("SELECT current_database();")[0]["current_database"]
+      expect(current_datebase_from_pg).to eq('shard1')
+    end
+  end
+
+  describe "Clients closing connection in the middle of transaction" do
+    it "sends a rollback to the server" do
+      conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      conn.async_exec("SET SERVER ROLE to 'primary'")
+      conn.async_exec("BEGIN")
+      conn.close
+
+      expect(processes.primary.count_query("ROLLBACK")).to eq(1)
+    end
+  end
+
+  describe "Server version reporting" do
+    it "reports correct version for normal and admin databases" do
+      server_conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+      expect(server_conn.server_version).not_to eq(0)
+      server_conn.close
+
+      admin_conn = PG::connect(processes.pgcat.admin_connection_string)
+      expect(admin_conn.server_version).not_to eq(0)
+      admin_conn.close
+    end
+  end
+
+  describe "State clearance" do
+    context "session mode" do
+      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5, "session") }
+
+      it "Clears state before connection checkin" do
+        # Both modes of operation should not raise
+        # ERROR:  prepared statement "prepared_q" already exists
+        15.times do
+          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+          conn.async_exec("PREPARE prepared_q (int) AS SELECT $1")
+          conn.close
+        end
+
+        conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        initial_value = conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]
+        conn.async_exec("SET statement_timeout to 1000")
+        current_value = conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]
+        expect(conn.async_exec("SHOW statement_timeout")[0]["statement_timeout"]).to eq("1s")
+        conn.close
+      end
+
+      it "Does not send DISCARD ALL unless necessary" 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.close
+        end
+
+        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
+
+        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("DISCARD ALL")).to eq(10)
+      end
+    end
+
+    context "transaction mode" do
+      let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5, "transaction") }
+      it "Clears state before connection checkin" do
+        # Both modes of operation should not raise
+        # ERROR:  prepared statement "prepared_q" already exists
+        15.times do
+          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+          conn.async_exec("PREPARE prepared_q (int) AS SELECT $1")
+          conn.close
+        end
+
+        15.times do
+          conn = PG::connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+          conn.prepare("prepared_q", "SELECT $1")
+          conn.close
+        end
+      end
+
+      it "Does not send DISCARD ALL unless necessary" 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.exec_params("SELECT $1", [1])
+          conn.close
+        end
+
+        expect(processes.primary.count_query("DISCARD ALL")).to eq(0)
+
+        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("DISCARD ALL")).to eq(10)
+      end
+    end
+  end
+end

tests/ruby/routing_spec.rb

@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+require_relative 'spec_helper'
+
+
+describe "Routing" do
+  let(:processes) { Helpers::Pgcat.single_shard_setup("sharded_db", 5) }
+  after do
+    processes.all_databases.map(&:reset)
+    processes.pgcat.shutdown
+  end
+
+  describe "SET ROLE" do
+    context "primary" do
+      it "routes queries only to primary" do
+        conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        conn.async_exec("SET SERVER ROLE to 'primary'")
+
+        query_count = 30
+        failed_count = 0
+
+        query_count.times do
+          conn.async_exec("SELECT 1 + 2")
+        rescue
+          failed_count += 1
+        end
+
+        expect(failed_count).to eq(0)
+        processes.replicas.map(&:count_select_1_plus_2).each do |instance_share|
+          expect(instance_share).to eq(0)
+        end
+
+        expect(processes.primary.count_select_1_plus_2).to eq(query_count)
+      end
+    end
+    context "replica" do
+      it "routes queries only to replicas" do
+        conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        conn.async_exec("SET SERVER ROLE to 'replica'")
+
+        expected_share = QUERY_COUNT / processes.replicas.count
+        failed_count = 0
+
+        QUERY_COUNT.times do
+          conn.async_exec("SELECT 1 + 2")
+        rescue
+          failed_count += 1
+        end
+
+        expect(failed_count).to eq(0)
+
+        processes.replicas.map(&:count_select_1_plus_2).each do |instance_share|
+          expect(instance_share).to be_within(expected_share * MARGIN_OF_ERROR).of(expected_share)
+        end
+
+        expect(processes.primary.count_select_1_plus_2).to eq(0)
+      end
+    end
+
+    context "any" do
+      it "routes queries to all instances" do
+        conn = PG.connect(processes.pgcat.connection_string("sharded_db", "sharding_user"))
+        conn.async_exec("SET SERVER ROLE to 'any'")
+
+        expected_share = QUERY_COUNT / processes.all_databases.count
+        failed_count = 0
+
+        QUERY_COUNT.times do
+          conn.async_exec("SELECT 1 + 2")
+        rescue
+          failed_count += 1
+        end
+
+        expect(failed_count).to eq(0)
+
+        processes.all_databases.map(&:count_select_1_plus_2).each do |instance_share|
+          expect(instance_share).to be_within(expected_share * MARGIN_OF_ERROR).of(expected_share)
+        end
+      end
+    end
+  end
+end

tests/ruby/spec_helper.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require 'pg'
+require_relative 'helpers/pgcat_helper'
+
+QUERY_COUNT = 300
+MARGIN_OF_ERROR = 0.30
+
+def with_captured_stdout_stderr
+  sout = STDOUT.clone
+  serr = STDERR.clone
+  STDOUT.reopen("/tmp/out.txt", "w+")
+  STDERR.reopen("/tmp/err.txt", "w+")
+  STDOUT.sync = true
+  STDERR.sync = true
+  yield
+  return File.read('/tmp/out.txt'), File.read('/tmp/err.txt')
+ensure
+  STDOUT.reopen(sout)
+  STDERR.reopen(serr)
+end

tests/ruby/tests.rb

@@ -1,9 +1,6 @@
 # frozen_string_literal: true
-
-require 'active_record'
 require 'pg'
-
-$stdout.sync = true
+require 'active_record'
 
 # Uncomment these two to see all queries.
 # ActiveRecord.verbose_query_logs = true
@@ -15,7 +12,7 @@ ActiveRecord::Base.establish_connection(
   port: 6432,
   username: 'sharding_user',
   password: 'sharding_user',
-  database: 'rails_dev',
+  database: 'sharded_db',
   application_name: 'testing_pgcat',
   prepared_statements: false, # Transaction mode
   advisory_locks: false # Same
@@ -114,17 +111,3 @@ begin
 rescue ActiveRecord::StatementInvalid
   puts 'OK'
 end
-
-# Test evil clients
-def poorly_behaved_client
-  conn = PG::connect("postgres://sharding_user:sharding_user@127.0.0.1:6432/rails_dev?application_name=testing_pgcat")
-  conn.async_exec 'BEGIN'
-  conn.async_exec 'SELECT 1'
-
-  conn.close
-  puts 'Bad client ok'
-end
-
-25.times do
-  poorly_behaved_client
-end

tests/sharding/query_routing_setup.sql

@@ -1,11 +1,12 @@
-
 DROP DATABASE IF EXISTS shard0;
 DROP DATABASE IF EXISTS shard1;
 DROP DATABASE IF EXISTS shard2;
+DROP DATABASE IF EXISTS some_db;
 
 CREATE DATABASE shard0;
 CREATE DATABASE shard1;
 CREATE DATABASE shard2;
+CREATE DATABASE some_db;
 
 \c shard0
 
@@ -41,21 +42,63 @@ CREATE TABLE data (
 
 CREATE TABLE data_shard_2 PARTITION OF data FOR VALUES WITH (MODULUS 3, REMAINDER 2);
 
-DROP ROLE IF EXISTS sharding_user;
-CREATE ROLE sharding_user ENCRYPTED PASSWORD 'sharding_user' LOGIN;
 
-GRANT CONNECT ON DATABASE shard0 TO sharding_user;
-GRANT CONNECT ON DATABASE shard1 TO sharding_user;
-GRANT CONNECT ON DATABASE shard2 TO sharding_user;
+\c some_db
+
+DROP TABLE IF EXISTS data CASCADE;
+
+CREATE TABLE data (
+    id BIGINT,
+    value VARCHAR
+);
+
+DROP ROLE IF EXISTS sharding_user;
+DROP ROLE IF EXISTS other_user;
+DROP ROLE IF EXISTS simple_user;
+CREATE ROLE sharding_user ENCRYPTED PASSWORD 'sharding_user' LOGIN;
+CREATE ROLE other_user ENCRYPTED PASSWORD 'other_user' LOGIN;
+CREATE ROLE simple_user ENCRYPTED PASSWORD 'simple_user' LOGIN;
+
+GRANT CONNECT ON DATABASE shard0  TO sharding_user;
+GRANT CONNECT ON DATABASE shard1  TO sharding_user;
+GRANT CONNECT ON DATABASE shard2  TO sharding_user;
+
+GRANT CONNECT ON DATABASE shard0  TO other_user;
+GRANT CONNECT ON DATABASE shard1  TO other_user;
+GRANT CONNECT ON DATABASE shard2  TO other_user;
+
+GRANT CONNECT ON DATABASE some_db TO simple_user;
 
 \c shard0
+CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO sharding_user;
 GRANT ALL ON SCHEMA public TO sharding_user;
 GRANT ALL ON TABLE data TO sharding_user;
+GRANT ALL ON SCHEMA public TO other_user;
+GRANT ALL ON TABLE data TO other_user;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO other_user;
 
 \c shard1
+CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO sharding_user;
 GRANT ALL ON SCHEMA public TO sharding_user;
 GRANT ALL ON TABLE data TO sharding_user;
+GRANT ALL ON SCHEMA public TO other_user;
+GRANT ALL ON TABLE data TO other_user;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO other_user;
+
 
 \c shard2
+CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO sharding_user;
 GRANT ALL ON SCHEMA public TO sharding_user;
 GRANT ALL ON TABLE data TO sharding_user;
+GRANT ALL ON SCHEMA public TO other_user;
+GRANT ALL ON TABLE data TO other_user;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO other_user;
+
+\c some_db
+CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
+GRANT EXECUTE ON FUNCTION pg_stat_statements_reset TO simple_user;
+GRANT ALL ON SCHEMA public TO simple_user;
+GRANT ALL ON TABLE data TO simple_user;

tests/sharding/query_routing_test_primary_replica.sql

@@ -151,3 +151,12 @@ SELECT 1;
 set server role to 'replica';
 SeT SeRver Role TO 'PrImARY';
 select 1;
+
+SET PRIMARY READS TO 'on';
+SELECT 1;
+
+SET PRIMARY READS TO 'off';
+SELECT 1;
+
+SET PRIMARY READS TO 'default';
+SELECT 1;