Add stats for connection errors

src/client/mod.rs

@@ -158,13 +158,13 @@ impl ConnectedClient {
         pipe(left, right, server.clone(), shared_buf)
             .then(move |result| match result {
                 Ok(amt) => {
-                    server.update_stats_conn_close();
+                    server.update_stats_conn_close(false);
                     debug!("tx {}, rx {} bytes ({} => {})",
                         amt.tx_bytes, amt.rx_bytes, server.tag, dest);
                     Ok(())
                 },
                 Err(_) => {
-                    server.update_stats_conn_close();
+                    server.update_stats_conn_close(true);
                     warn!("{} (=> {}) close with error",
                         server.tag, dest);
                     Err(())

src/monitor/mod.rs

@@ -156,6 +156,7 @@ fn send_metrics(monitor: Monitor, handle: Handle)
                 Some(r("rx_bytes", traffic.rx_bytes as u64)),
                 Some(r("conns.total", server.conn_total() as u64)),
                 Some(r("conns.alive", server.conn_alive() as u64)),
+                Some(r("conns.error", server.conn_error() as u64)),
             ]
         }).filter_map(|v| v);
         let mut buf = Vec::new();

src/proxy/mod.rs

@@ -55,6 +55,7 @@ struct ProxyServerStatus {
     traffic: Traffic,
     conn_alive: u32,
     conn_total: u32,
+    conn_error: u32,
 }
 
 impl Hash for ProxyServer {
@@ -207,6 +208,10 @@ impl ProxyServer {
         self.status().conn_total
     }
 
+    pub fn conn_error(&self) -> u32 {
+        self.status().conn_error
+    }
+
     pub fn set_delay(&self, delay: Option<Duration>) {
         self.status().delay = delay;
         self.status().score =
@@ -241,8 +246,11 @@ impl ProxyServer {
         self.status().conn_total += 1;
     }
 
-    pub fn update_stats_conn_close(&self) {
+    pub fn update_stats_conn_close(&self, has_error: bool) {
         self.status().conn_alive -= 1;
+        if has_error {
+            self.status().conn_error += 1;
+        }
     }
 
     pub fn traffic(&self) -> Traffic {