renaming

weed/mq/broker/broker_grpc_server_discovery.go

@@ -0,0 +1,122 @@
+package broker
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/cluster"
+	"github.com/chrislusf/seaweedfs/weed/pb"
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/mq_pb"
+)
+
+/*
+Topic discovery:
+
+When pub or sub connects, it ask for the whole broker list, and run consistent hashing to find the broker.
+
+The broker will check peers whether it is already hosted by some other broker, if that broker is alive and acknowledged alive, redirect to it.
+Otherwise, just host the topic.
+
+So, if the pub or sub connects around the same time, they would connect to the same broker. Everyone is happy.
+If one of the pub or sub connects very late, and the system topo changed quite a bit with new servers added or old servers died, checking peers will help.
+
+*/
+
+func (broker *MessageBroker) FindBroker(c context.Context, request *mq_pb.FindBrokerRequest) (*mq_pb.FindBrokerResponse, error) {
+
+	t := &mq_pb.FindBrokerResponse{}
+	var peers []string
+
+	targetTopicPartition := fmt.Sprintf(TopicPartitionFmt, request.Namespace, request.Topic, request.Parition)
+
+	for _, filer := range broker.option.Filers {
+		err := broker.withFilerClient(false, filer, func(client filer_pb.SeaweedFilerClient) error {
+			resp, err := client.LocateBroker(context.Background(), &filer_pb.LocateBrokerRequest{
+				Resource: targetTopicPartition,
+			})
+			if err != nil {
+				return err
+			}
+			if resp.Found && len(resp.Resources) > 0 {
+				t.Broker = resp.Resources[0].GrpcAddresses
+				return nil
+			}
+			for _, b := range resp.Resources {
+				peers = append(peers, b.GrpcAddresses)
+			}
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	t.Broker = PickMember(peers, []byte(targetTopicPartition))
+
+	return t, nil
+
+}
+
+func (broker *MessageBroker) checkFilers() {
+
+	// contact a filer about masters
+	var masters []pb.ServerAddress
+	found := false
+	for !found {
+		for _, filer := range broker.option.Filers {
+			err := broker.withFilerClient(false, filer, func(client filer_pb.SeaweedFilerClient) error {
+				resp, err := client.GetFilerConfiguration(context.Background(), &filer_pb.GetFilerConfigurationRequest{})
+				if err != nil {
+					return err
+				}
+				for _, m := range resp.Masters {
+					masters = append(masters, pb.ServerAddress(m))
+				}
+				return nil
+			})
+			if err == nil {
+				found = true
+				break
+			}
+			glog.V(0).Infof("failed to read masters from %+v: %v", broker.option.Filers, err)
+			time.Sleep(time.Second)
+		}
+	}
+	glog.V(0).Infof("received master list: %s", masters)
+
+	// contact each masters for filers
+	var filers []pb.ServerAddress
+	found = false
+	for !found {
+		for _, master := range masters {
+			err := broker.withMasterClient(false, master, func(client master_pb.SeaweedClient) error {
+				resp, err := client.ListClusterNodes(context.Background(), &master_pb.ListClusterNodesRequest{
+					ClientType: cluster.FilerType,
+				})
+				if err != nil {
+					return err
+				}
+
+				for _, clusterNode := range resp.ClusterNodes {
+					filers = append(filers, pb.ServerAddress(clusterNode.Address))
+				}
+
+				return nil
+			})
+			if err == nil {
+				found = true
+				break
+			}
+			glog.V(0).Infof("failed to list filers: %v", err)
+			time.Sleep(time.Second)
+		}
+	}
+	glog.V(0).Infof("received filer list: %s", filers)
+
+	broker.option.Filers = filers
+
+}