Changeset 71 in code for trunk

Timestamp:

Mar 3, 2020, 2:26:19 PM (5 years ago)

Author:

contact

Message:

Retry connecting to upstream servers

Rate-limit retries in case connecting immediately fails.

File:

• trunk/server.go (modified) (3 diffs)

trunk/server.go

@@ -13 +13 @@
 // TODO: make configurable
 var keepAlivePeriod = time.Minute
+var retryConnectMinDelay = time.Minute
 
 func setKeepAlive(c net.Conn) error {
@@ -138 +139 @@
 }
 
+func (s *Server) runUpstream(u *user, upstream *Upstream) {
+        var lastTry time.Time
+        for {
+                if dur := time.Now().Sub(lastTry); dur < retryConnectMinDelay {
+                        delay := retryConnectMinDelay - dur
+                        s.Logger.Printf("waiting %v before trying to reconnect to %q", delay.Truncate(time.Second), upstream.Addr)
+                        time.Sleep(delay)
+                }
+                lastTry = time.Now()
+
+                uc, err := connectToUpstream(u, upstream)
+                if err != nil {
+                        s.Logger.Printf("failed to connect to upstream server %q: %v", upstream.Addr, err)
+                        continue
+                }
+
+                uc.register()
+
+                u.lock.Lock()
+                u.upstreamConns = append(u.upstreamConns, uc)
+                u.lock.Unlock()
+
+                if err := uc.readMessages(); err != nil {
+                        uc.logger.Printf("failed to handle messages: %v", err)
+                }
+                uc.Close()
+
+                u.lock.Lock()
+                for i := range u.upstreamConns {
+                        if u.upstreamConns[i] == uc {
+                                u.upstreamConns = append(u.upstreamConns[:i], u.upstreamConns[i+1:]...)
+                                break
+                        }
+                }
+                u.lock.Unlock()
+        }
+}
+
 func (s *Server) Run() {
         // TODO: multi-user
@@ -147 +186 @@
 
         for i := range s.Upstreams {
-                upstream := &s.Upstreams[i]
-                // TODO: retry connecting
-                go func() {
-                        uc, err := connectToUpstream(u, upstream)
-                        if err != nil {
-                                s.Logger.Printf("failed to connect to upstream server %q: %v", upstream.Addr, err)
-                                return
-                        }
-
-                        uc.register()
-
-                        u.lock.Lock()
-                        u.upstreamConns = append(u.upstreamConns, uc)
-                        u.lock.Unlock()
-
-                        if err := uc.readMessages(); err != nil {
-                                uc.logger.Printf("failed to handle messages: %v", err)
-                        }
-                        uc.Close()
-
-                        u.lock.Lock()
-                        for i := range u.upstreamConns {
-                                if u.upstreamConns[i] == uc {
-                                        u.upstreamConns = append(u.upstreamConns[:i], u.upstreamConns[i+1:]...)
-                                        break
-                                }
-                        }
-                        u.lock.Unlock()
-                }()
+                go s.runUpstream(u, &s.Upstreams[i])
         }
 }