Merge pull request #1963 from Shopify/dnwe/fix-leaky-consumergroup

fix: ensure backoff timer is re-used

consumer_group.go

@@ -732,6 +732,9 @@ func (s *consumerGroupSession) heartbeatLoop() {
 	pause := time.NewTicker(s.parent.config.Consumer.Group.Heartbeat.Interval)
 	defer pause.Stop()
 
+	retryBackoff := time.NewTimer(s.parent.config.Metadata.Retry.Backoff)
+	defer retryBackoff.Stop()
+
 	retries := s.parent.config.Metadata.Retry.Max
 	for {
 		coordinator, err := s.parent.client.Coordinator(s.parent.groupID)
@@ -740,11 +743,11 @@ func (s *consumerGroupSession) heartbeatLoop() {
 				s.parent.handleError(err, "", -1)
 				return
 			}
-
+			retryBackoff.Reset(s.parent.config.Metadata.Retry.Backoff)
 			select {
 			case <-s.hbDying:
 				return
-			case <-time.After(s.parent.config.Metadata.Retry.Backoff):
+			case <-retryBackoff.C:
 				retries--
 			}
 			continue