Changeset 735 in code

Timestamp:

Dec 2, 2021, 11:14:35 AM (4 years ago)

Author:

contact

Message:

Add exponential backoff when re-connecting to upstream

The first reconnection attempt waits for 1min, the second the 2min,
and so on up to 10min. There's a 1min jitter so that multiple failed
connections don't try to reconnect at the exact same time.

Closes: ​https://todo.sr.ht/~emersion/soju/161

Location:

trunk

Files:

• rate.go (added)
• server.go (modified) (1 diff)
• user.go (modified) (3 diffs)

trunk/server.go

@@ -24 +24 @@
 
 // TODO: make configurable
-var retryConnectDelay = time.Minute
+var retryConnectMinDelay = time.Minute
+var retryConnectMaxDelay = 10 * time.Minute
+var retryConnectJitter = time.Minute
 var connectTimeout = 15 * time.Second
 var writeTimeout = 10 * time.Second

trunk/user.go

@@ -191 +191 @@
 
         var lastTry time.Time
+        backoff := newBackoffer(retryConnectMinDelay, retryConnectMaxDelay, retryConnectJitter)
         for {
                 if net.isStopped() {
@@ -196 +197 @@
                 }
 
-                if dur := time.Now().Sub(lastTry); dur < retryConnectDelay {
-                        delay := retryConnectDelay - dur
+                delay := backoff.Next() - time.Now().Sub(lastTry)
+                if delay > 0 {
                         net.logger.Printf("waiting %v before trying to reconnect to %q", delay.Truncate(time.Second), net.Addr)
                         time.Sleep(delay)
@@ -248 +249 @@
 
                 net.user.srv.metrics.upstreams.Add(-1)
+                backoff.Reset()
         }
 }