retry connecting to broker leader

weed/mq/broker/broker_connect.go

@@ -12,7 +12,8 @@ import (
 )
 
 // BrokerConnectToBalancer connects to the broker balancer and sends stats
-func (b *MessageQueueBroker) BrokerConnectToBalancer(brokerBalancer string) error {
+func (b *MessageQueueBroker) BrokerConnectToBalancer(brokerBalancer string, stopCh chan struct{}) error {
+
 	self := string(b.option.BrokerAddress())
 
 	glog.V(0).Infof("broker %s connects to balancer %s", self, brokerBalancer)
@@ -39,6 +40,13 @@ func (b *MessageQueueBroker) BrokerConnectToBalancer(brokerBalancer string) erro
 		}
 
 		for {
+			// check if the broker is stopping
+			select {
+			case <-stopCh:
+				return nil
+			default:
+			}
+
 			stats := b.localTopicManager.CollectStats(time.Second * 5)
 			err = stream.Send(&mq_pb.PublisherToPubBalancerRequest{
 				Message: &mq_pb.PublisherToPubBalancerRequest_Stats{
@@ -55,7 +63,40 @@ func (b *MessageQueueBroker) BrokerConnectToBalancer(brokerBalancer string) erro
 
 			time.Sleep(time.Millisecond*5000 + time.Duration(rand.Intn(1000))*time.Millisecond)
 		}
-
-		return nil
 	})
 }
+
+func (b *MessageQueueBroker) KeepConnectedToBrokerBalancer(newBrokerBalancerCh chan string) {
+	var stopPrevRunChan chan struct{}
+	for {
+		select {
+		case newBrokerBalancer := <-newBrokerBalancerCh:
+			if stopPrevRunChan != nil {
+				close(stopPrevRunChan)
+				stopPrevRunChan = nil
+			}
+			thisRunStopChan := make(chan struct{})
+			if newBrokerBalancer != "" {
+				stopPrevRunChan = thisRunStopChan
+				go func() {
+					for {
+						err := b.BrokerConnectToBalancer(newBrokerBalancer, thisRunStopChan)
+						if err != nil {
+							glog.V(0).Infof("connect to balancer %s: %v", newBrokerBalancer, err)
+							time.Sleep(time.Second)
+						} else {
+							break
+						}
+
+						select {
+						case <-thisRunStopChan:
+							return
+						default:
+						}
+
+					}
+				}()
+			}
+		}
+	}
+}

weed/mq/broker/broker_server.go

@@ -1,7 +1,6 @@
 package broker
 
 import (
-	"github.com/seaweedfs/seaweedfs/weed/cluster/lock_manager"
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/mq/pub_balancer"
 	"github.com/seaweedfs/seaweedfs/weed/mq/sub_coordinator"
@@ -84,19 +83,13 @@ func NewMessageBroker(option *MessageQueueBrokerOption, grpcDialOption grpc.Dial
 		self := option.BrokerAddress()
 		glog.V(0).Infof("broker %s found filer %s", self, mqBroker.currentFiler)
 
+		newBrokerBalancerCh := make(chan string, 1)
 		lockClient := cluster.NewLockClient(grpcDialOption, mqBroker.currentFiler)
 		mqBroker.lockAsBalancer = lockClient.StartLongLivedLock(pub_balancer.LockBrokerBalancer, string(self), func(newLockOwner string) {
-			// FIXME this is a blocking call, should be in a goroutine
+			glog.V(0).Infof("broker %s found balanacer %s", self, newLockOwner)
-			if err := mqBroker.BrokerConnectToBalancer(newLockOwner); err != nil {
+			newBrokerBalancerCh <- newLockOwner
-				glog.V(0).Infof("BrokerConnectToBalancer %s: %v", newLockOwner, err)
-			}
 		})
-		for {
+		mqBroker.KeepConnectedToBrokerBalancer(newBrokerBalancerCh)
-			time.Sleep(lock_manager.RenewInterval)
-			if err := mqBroker.lockAsBalancer.AttemptToLock(lock_manager.LiveLockTTL); err != nil {
-				glog.V(4).Infof("AttemptToLock: %v", err)
-			}
-		}
 	}()
 
 	return mqBroker, nil