able to detect disconnected subscribers

weed/messaging/broker/broker_grpc_server_subscribe.go

@@ -50,6 +50,17 @@ func (broker *MessageBroker) Subscribe(stream messaging_pb.SeaweedMessaging_Subs
 	lock := broker.topicManager.RequestLock(tp, topicConfig, false)
 	defer broker.topicManager.ReleaseLock(tp, false)
 
+	isConnected := true
+	go func() {
+		for isConnected {
+			time.Sleep(1737 * time.Millisecond)
+			if err = stream.Send(&messaging_pb.BrokerMessage{}); err != nil {
+				isConnected = false
+				lock.cond.Signal()
+			}
+		}
+	}()
+
 	lastReadTime := time.Now()
 	switch in.Init.StartPosition {
 	case messaging_pb.SubscriberMessage_InitMessage_TIMESTAMP:
@@ -93,8 +104,10 @@ func (broker *MessageBroker) Subscribe(stream messaging_pb.SeaweedMessaging_Subs
 	}
 
 	if err := broker.readPersistedLogBuffer(&tp, lastReadTime, eachLogEntryFn); err != nil {
-		// println("stopping from persisted logs")
-		return err
+		if err != io.EOF {
+			println("stopping from persisted logs", err.Error())
+			return err
+		}
 	}
 
 	if processedTsNs != 0 {
@@ -105,7 +118,7 @@ func (broker *MessageBroker) Subscribe(stream messaging_pb.SeaweedMessaging_Subs
 		lock.Mutex.Lock()
 		lock.cond.Wait()
 		lock.Mutex.Unlock()
-		return true
+		return isConnected
 	}, eachLogEntryFn)
 
 	return err

weed/messaging/msgclient/sub_chan.go

@@ -27,7 +27,7 @@ func (mc *MessagingClient) NewSubChannel(subscriberId, chanName string) (*SubCha
 	if err != nil {
 		return nil, err
 	}
-	sc, err := setupSubscriberClient(grpcConnection, subscriberId, "chan", chanName, 0, time.Unix(0, 0))
+	sc, err := setupSubscriberClient(grpcConnection, tp, subscriberId, time.Unix(0, 0))
 	if err != nil {
 		return nil, err
 	}
@@ -48,6 +48,10 @@ func (mc *MessagingClient) NewSubChannel(subscriberId, chanName string) (*SubCha
 				log.Printf("fail to receive from netchan %s: %v", chanName, subErr)
 				return
 			}
+			if resp.Data == nil {
+				// this could be heartbeat from broker
+				continue
+			}
 			if resp.Data.IsClose {
 				t.stream.Send(&messaging_pb.SubscriberMessage{
 					IsClose: true,

weed/messaging/msgclient/subscriber.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"time"
 
+	"github.com/chrislusf/seaweedfs/weed/messaging/broker"
 	"github.com/chrislusf/seaweedfs/weed/pb/messaging_pb"
 	"google.golang.org/grpc"
 )
@@ -14,7 +15,6 @@ type Subscriber struct {
 	subscriberId      string
 }
 
-/*
 func (mc *MessagingClient) NewSubscriber(subscriberId, namespace, topic string, startTime time.Time) (*Subscriber, error) {
 	// read topic configuration
 	topicConfiguration := &messaging_pb.TopicConfiguration{
@@ -23,7 +23,16 @@ func (mc *MessagingClient) NewSubscriber(subscriberId, namespace, topic string,
 	subscriberClients := make([]messaging_pb.SeaweedMessaging_SubscribeClient, topicConfiguration.PartitionCount)
 
 	for i := 0; i < int(topicConfiguration.PartitionCount); i++ {
-		client, err := mc.setupSubscriberClient(subscriberId, namespace, topic, int32(i), startTime)
+		tp := broker.TopicPartition{
+			Namespace: namespace,
+			Topic: topic,
+			Partition: int32(i),
+		}
+		grpcClientConn, err := mc.findBroker(tp)
+		if err != nil {
+			return nil, err
+		}
+		client, err := setupSubscriberClient(grpcClientConn, tp, subscriberId, startTime)
 		if err != nil {
 			return nil, err
 		}
@@ -36,22 +45,7 @@ func (mc *MessagingClient) NewSubscriber(subscriberId, namespace, topic string,
 	}, nil
 }
 
-func (mc *MessagingClient) setupSubscriberClient(subscriberId, namespace, topic string, partition int32, startTime time.Time) (messaging_pb.SeaweedMessaging_SubscribeClient, error) {
-
-	stream, err := setupSubscriberClient(subscriberId, namespace, topic, partition, startTime)
-	if err != nil {
-		return stream, err
-	}
-	if newBroker != nil {
-
-	}
-
-	return stream, nil
-
-}
-*/
-
-func setupSubscriberClient(grpcConnection *grpc.ClientConn, subscriberId string, namespace string, topic string, partition int32, startTime time.Time) (stream messaging_pb.SeaweedMessaging_SubscribeClient, err error) {
+func setupSubscriberClient(grpcConnection *grpc.ClientConn, tp broker.TopicPartition, subscriberId string, startTime time.Time) (stream messaging_pb.SeaweedMessaging_SubscribeClient, err error) {
 	stream, err = messaging_pb.NewSeaweedMessagingClient(grpcConnection).Subscribe(context.Background())
 	if err != nil {
 		return
@@ -60,9 +54,9 @@ func setupSubscriberClient(grpcConnection *grpc.ClientConn, subscriberId string,
 	// send init message
 	err = stream.Send(&messaging_pb.SubscriberMessage{
 		Init: &messaging_pb.SubscriberMessage_InitMessage{
-			Namespace:     namespace,
-			Topic:         topic,
-			Partition:     partition,
+			Namespace:     tp.Namespace,
+			Topic:         tp.Topic,
+			Partition:     tp.Partition,
 			StartPosition: messaging_pb.SubscriberMessage_InitMessage_TIMESTAMP,
 			TimestampNs:   startTime.UnixNano(),
 			SubscriberId:  subscriberId,
@@ -90,6 +84,10 @@ func (s *Subscriber) doSubscribe(partition int, processFn func(m *messaging_pb.M
 			println(listenErr.Error())
 			return listenErr
 		}
+		if resp.Data == nil {
+			// this could be heartbeat from broker
+			continue
+		}
 		processFn(resp.Data)
 	}
 }