More statistics (#20)

* cleaner stats

* remove shard selection there

src/client.rs

@@ -57,6 +57,7 @@ pub struct Client {
     default_server_role: Option<Role>,
 
     // Client parameters, e.g. user, client_encoding, etc.
+    #[allow(dead_code)]
     parameters: HashMap<String, String>,
 
     // Statistics
@@ -302,8 +303,11 @@ impl Client {
 
                             // Release server
                             if self.transaction_mode {
+                                self.stats.client_idle();
+
                                 shard = None;
                                 role = self.default_server_role;
+
                                 break;
                             }
                         }
@@ -371,8 +375,11 @@ impl Client {
                             self.stats.transaction();
 
                             if self.transaction_mode {
+                                self.stats.client_idle();
+
                                 shard = None;
                                 role = self.default_server_role;
+
                                 break;
                             }
                         }

src/config.rs

@@ -17,6 +17,7 @@ pub enum Role {
 pub struct Address {
     pub host: String,
     pub port: String,
+    pub shard: usize,
     pub role: Role,
 }
 

src/pool.rs

@@ -57,7 +57,7 @@ impl ConnectionPool {
             let mut pools = Vec::new();
             let mut replica_addresses = Vec::new();
 
-            for server in &shard.servers {
+            for (idx, server) in shard.servers.iter().enumerate() {
                 let role = match server.2.as_ref() {
                     "primary" => Role::Primary,
                     "replica" => Role::Replica,
@@ -71,6 +71,7 @@ impl ConnectionPool {
                     host: server.0.clone(),
                     port: server.1.to_string(),
                     role: role,
+                    shard: idx,
                 };
 
                 let manager = ServerPool::new(
@@ -165,6 +166,9 @@ impl ConnectionPool {
             None => 0, // TODO: pick a shard at random
         };
 
+        // We are waiting for a server now.
+        self.stats.client_waiting();
+
         let addresses = &self.addresses[shard];
 
         // Make sure if a specific role is requested, it's available in the pool.
@@ -237,7 +241,8 @@ impl ConnectionPool {
             };
 
             if !with_health_check {
-                self.stats.checkout_time(now.elapsed().as_millis());
+                self.stats.checkout_time(now.elapsed().as_micros());
+                self.stats.client_active();
                 return Ok((conn, address.clone()));
             }
 
@@ -253,7 +258,8 @@ impl ConnectionPool {
                 // Check if health check succeeded
                 Ok(res) => match res {
                     Ok(_) => {
-                        self.stats.checkout_time(now.elapsed().as_millis());
+                        self.stats.checkout_time(now.elapsed().as_micros());
+                        self.stats.client_active();
                         return Ok((conn, address.clone()));
                     }
                     Err(_) => {
@@ -385,13 +391,10 @@ impl ManageConnection for ServerPool {
         println!(">> Creating a new connection for the pool");
 
         Server::startup(
-            &self.address.host,
+            &self.address,
-            &self.address.port,
+            &self.user,
-            &self.user.name,
-            &self.user.password,
             &self.database,
             self.client_server_map.clone(),
-            self.address.role,
             self.stats.clone(),
         )
         .await

src/server.rs

@@ -8,7 +8,7 @@ use tokio::io::{AsyncReadExt, BufReader};
 use tokio::net::tcp::{OwnedReadHalf, OwnedWriteHalf};
 use tokio::net::TcpStream;
 
-use crate::config::{Address, Role};
+use crate::config::{Address, User};
 use crate::errors::Error;
 use crate::messages::*;
 use crate::stats::Reporter;
@@ -16,11 +16,9 @@ use crate::ClientServerMap;
 
 /// Server state.
 pub struct Server {
-    // Server host, e.g. localhost
+    // Server host, e.g. localhost,
-    host: String,
+    // port, e.g. 5432, and role, e.g. primary or replica.
-
+    address: Address,
-    // Server port: e.g. 5432
-    port: String,
 
     // Buffered read socket
     read: BufReader<OwnedReadHalf>,
@@ -50,9 +48,6 @@ pub struct Server {
     // Mapping of clients and servers used for query cancellation.
     client_server_map: ClientServerMap,
 
-    // Server role, e.g. primary or replica.
-    role: Role,
-
     // Server connected at
     connected_at: chrono::naive::NaiveDateTime,
 
@@ -64,25 +59,23 @@ impl Server {
     /// Pretend to be the Postgres client and connect to the server given host, port and credentials.
     /// Perform the authentication and return the server in a ready-for-query mode.
     pub async fn startup(
-        host: &str,
+        address: &Address,
-        port: &str,
+        user: &User,
-        user: &str,
-        password: &str,
         database: &str,
         client_server_map: ClientServerMap,
-        role: Role,
         stats: Reporter,
     ) -> Result<Server, Error> {
-        let mut stream = match TcpStream::connect(&format!("{}:{}", host, port)).await {
+        let mut stream =
-            Ok(stream) => stream,
+            match TcpStream::connect(&format!("{}:{}", &address.host, &address.port)).await {
-            Err(err) => {
+                Ok(stream) => stream,
-                println!(">> Could not connect to server: {}", err);
+                Err(err) => {
-                return Err(Error::SocketError);
+                    println!(">> Could not connect to server: {}", err);
-            }
+                    return Err(Error::SocketError);
-        };
+                }
+            };
 
         // Send the startup packet.
-        startup(&mut stream, user, database).await?;
+        startup(&mut stream, &user.name, database).await?;
 
         let mut server_info = BytesMut::with_capacity(25);
         let mut backend_id: i32 = 0;
@@ -117,7 +110,8 @@ impl Server {
                                 Err(_) => return Err(Error::SocketError),
                             };
 
-                            md5_password(&mut stream, user, password, &salt[..]).await?;
+                            md5_password(&mut stream, &user.name, &user.password, &salt[..])
+                                .await?;
                         }
 
                         // Authentication handshake complete.
@@ -189,8 +183,7 @@ impl Server {
                     let (read, write) = stream.into_split();
 
                     return Ok(Server {
-                        host: host.to_string(),
+                        address: address.clone(),
-                        port: port.to_string(),
                         read: BufReader::new(read),
                         write: write,
                         buffer: BytesMut::with_capacity(8196),
@@ -201,7 +194,6 @@ impl Server {
                         data_available: false,
                         bad: false,
                         client_server_map: client_server_map,
-                        role: role,
                         connected_at: chrono::offset::Utc::now().naive_utc(),
                         stats: stats,
                     });
@@ -382,8 +374,8 @@ impl Server {
             (
                 self.backend_id,
                 self.secret_key,
-                self.host.clone(),
+                self.address.host.clone(),
-                self.port.clone(),
+                self.address.port.clone(),
             ),
         );
     }
@@ -422,11 +414,7 @@ impl Server {
     }
 
     pub fn address(&self) -> Address {
-        Address {
+        self.address.clone()
-            host: self.host.to_string(),
-            port: self.port.to_string(),
-            role: self.role,
-        }
     }
 }
 

src/stats.rs

@@ -14,6 +14,9 @@ pub enum StatisticName {
     Transactions,
     DataSent,
     DataReceived,
+    ClientsWaiting,
+    ClientsActive,
+    ClientsIdle,
 }
 
 #[derive(Debug)]
@@ -76,6 +79,54 @@ impl Reporter {
 
         let _ = self.tx.try_send(statistic);
     }
+
+    pub fn client_waiting(&mut self) {
+        let statistic = Statistic {
+            name: StatisticName::ClientsWaiting,
+            value: 1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+
+        let statistic = Statistic {
+            name: StatisticName::ClientsIdle,
+            value: -1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+    }
+
+    pub fn client_active(&mut self) {
+        let statistic = Statistic {
+            name: StatisticName::ClientsWaiting,
+            value: -1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+
+        let statistic = Statistic {
+            name: StatisticName::ClientsActive,
+            value: 1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+    }
+
+    pub fn client_idle(&mut self) {
+        let statistic = Statistic {
+            name: StatisticName::ClientsActive,
+            value: -1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+
+        let statistic = Statistic {
+            name: StatisticName::ClientsIdle,
+            value: 1,
+        };
+
+        let _ = self.tx.try_send(statistic);
+    }
 }
 
 pub struct Collector {
@@ -93,12 +144,18 @@ impl Collector {
 
     pub async fn collect(&mut self) {
         let mut stats = HashMap::from([
-            ("queries", 0),
+            ("total_query_count", 0),
-            ("transactions", 0),
+            ("total_xact_count", 0),
-            ("data_sent", 0),
+            ("total_sent", 0),
-            ("data_received", 0),
+            ("total_received", 0),
-            ("checkout_time", 0),
+            ("total_wait_time", 0),
+            ("maxwait_us", 0),
+            ("maxwait", 0),
+            ("cl_waiting", 0),
+            ("cl_active", 0),
+            ("cl_idle", 0),
         ]);
+
         let mut now = Instant::now();
 
         loop {
@@ -113,32 +170,61 @@ impl Collector {
             // Some are counters, some are gauges...
             match stat.name {
                 StatisticName::Queries => {
-                    let counter = stats.entry("queries").or_insert(0);
+                    let counter = stats.entry("total_query_count").or_insert(0);
                     *counter += stat.value;
                 }
 
                 StatisticName::Transactions => {
-                    let counter = stats.entry("transactions").or_insert(0);
+                    let counter = stats.entry("total_xact_count").or_insert(0);
                     *counter += stat.value;
                 }
 
                 StatisticName::DataSent => {
-                    let counter = stats.entry("data_sent").or_insert(0);
+                    let counter = stats.entry("total_sent").or_insert(0);
                     *counter += stat.value;
                 }
 
                 StatisticName::DataReceived => {
-                    let counter = stats.entry("data_received").or_insert(0);
+                    let counter = stats.entry("total_received").or_insert(0);
                     *counter += stat.value;
                 }
 
                 StatisticName::CheckoutTime => {
-                    let counter = stats.entry("checkout_time").or_insert(0);
+                    let counter = stats.entry("total_wait_time").or_insert(0);
+                    *counter += stat.value;
+
+                    let counter = stats.entry("maxwait_us").or_insert(0);
 
                     // Report max time here
                     if stat.value > *counter {
                         *counter = stat.value;
                     }
+
+                    let counter = stats.entry("maxwait").or_insert(0);
+                    let seconds = *counter / 1_000_000;
+
+                    if seconds > *counter {
+                        *counter = seconds;
+                    }
+                }
+
+                StatisticName::ClientsActive => {
+                    let counter = stats.entry("cl_active").or_insert(0);
+
+                    *counter += stat.value;
+                    *counter = std::cmp::max(*counter, 0);
+                }
+
+                StatisticName::ClientsWaiting => {
+                    let counter = stats.entry("cl_waiting").or_insert(0);
+                    *counter += stat.value;
+                    *counter = std::cmp::max(*counter, 0);
+                }
+
+                StatisticName::ClientsIdle => {
+                    let counter = stats.entry("cl_idle").or_insert(0);
+                    *counter += stat.value;
+                    *counter = std::cmp::max(*counter, 0);
                 }
             };