From 14a2cc83bf35c2c30bb2306cca128ca8a1eb8286 Mon Sep 17 00:00:00 2001
From: Konstantin Lebedev <9497591+kmlebedev@users.noreply.github.com>
Date: Wed, 6 Apr 2022 21:17:04 +0500
Subject: [PATCH] raft update peers via OnPeerUpdate

---
 weed/cluster/cluster.go       | 18 ++++++++++++++
 weed/server/master_server.go  | 46 +++++++++++++++++++++++++++++++++--
 weed/server/raft_hashicorp.go |  9 ++++---
 3 files changed, 68 insertions(+), 5 deletions(-)

diff --git a/weed/cluster/cluster.go b/weed/cluster/cluster.go
index e8752f4d9..3cff13724 100644
--- a/weed/cluster/cluster.go
+++ b/weed/cluster/cluster.go
@@ -81,6 +81,15 @@ func (cluster *Cluster) AddClusterNode(nodeType string, address pb.ServerAddress
 			},
 		}
 	case MasterType:
+		return []*master_pb.KeepConnectedResponse{
+			{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsAdd:    true,
+				},
+			},
+		}
 	}
 	return nil
 }
@@ -120,6 +129,15 @@ func (cluster *Cluster) RemoveClusterNode(nodeType string, address pb.ServerAddr
 			}
 		}
 	case MasterType:
+		return []*master_pb.KeepConnectedResponse{
+			{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsAdd:    false,
+				},
+			},
+		}
 	}
 	return nil
 }
diff --git a/weed/server/master_server.go b/weed/server/master_server.go
index 37e7f245c..2c626b511 100644
--- a/weed/server/master_server.go
+++ b/weed/server/master_server.go
@@ -1,6 +1,7 @@
 package weed_server
 
 import (
+	"context"
 	"fmt"
 	"github.com/chrislusf/seaweedfs/weed/stats"
 	"net/http"
@@ -17,6 +18,7 @@ import (
 
 	"github.com/chrislusf/raft"
 	"github.com/gorilla/mux"
+	hashicorpRaft "github.com/hashicorp/raft"
 	"google.golang.org/grpc"
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -30,8 +32,9 @@ import (
 )
 
 const (
-	SequencerType        = "master.sequencer.type"
-	SequencerSnowflakeId = "master.sequencer.sequencer_snowflake_id"
+	SequencerType         = "master.sequencer.type"
+	SequencerSnowflakeId  = "master.sequencer.sequencer_snowflake_id"
+	RaftServerRemovalTime = 72 * time.Hour
 )
 
 type MasterOption struct {
@@ -61,6 +64,7 @@ type MasterServer struct {
 	vgCh chan *topology.VolumeGrowRequest
 
 	boundedLeaderChan chan int
+	onPeerUpdatDoneCn chan string
 
 	// notifying clients
 	clientChansLock sync.RWMutex
@@ -112,6 +116,8 @@ func NewMasterServer(r *mux.Router, option *MasterOption, peers map[string]pb.Se
 		Cluster:         cluster.NewCluster(),
 	}
 	ms.boundedLeaderChan = make(chan int, 16)
+	ms.onPeerUpdatDoneCn = make(chan string)
+	ms.MasterClient.OnPeerUpdate = ms.OnPeerUpdate
 
 	seq := ms.createSequencer(option)
 	if nil == seq {
@@ -323,3 +329,39 @@ func (ms *MasterServer) createSequencer(option *MasterOption) sequence.Sequencer
 	}
 	return seq
 }
+
+func (ms *MasterServer) OnPeerUpdate(update *master_pb.ClusterNodeUpdate) {
+	glog.V(0).Infof("OnPeerUpdate: %+v", update)
+	if update.NodeType != cluster.MasterType || ms.Topo.HashicorpRaft == nil {
+		return
+	}
+	peerAddress := pb.ServerAddress(update.Address)
+	if update.IsAdd {
+		if ms.Topo.HashicorpRaft.State() == hashicorpRaft.Leader {
+			glog.V(0).Infof("adding new raft server: %s", peerAddress.String())
+			ms.Topo.HashicorpRaft.AddVoter(
+				hashicorpRaft.ServerID(peerAddress.String()),
+				hashicorpRaft.ServerAddress(peerAddress.ToGrpcAddress()), 0, 0)
+		}
+		ms.onPeerUpdatDoneCn <- string(peerAddress)
+	} else if ms.Topo.HashicorpRaft.State() == hashicorpRaft.Leader {
+		go func(peerName string) {
+			for {
+				select {
+				case peerDone := <-ms.onPeerUpdatDoneCn:
+					if peerName == peerDone {
+						return
+					}
+				case <-time.After(RaftServerRemovalTime):
+					glog.V(0).Infof("removing old raft server: %s", peerName)
+					if _, err := ms.RaftRemoveServer(context.Background(), &master_pb.RaftRemoveServerRequest{
+						Id: peerName,
+					}); err != nil {
+						glog.Warningf("failed removing old raft server: %v", err)
+					}
+					return
+				}
+			}
+		}(string(peerAddress))
+	}
+}
diff --git a/weed/server/raft_hashicorp.go b/weed/server/raft_hashicorp.go
index 3ce3ebcda..885ffdcc7 100644
--- a/weed/server/raft_hashicorp.go
+++ b/weed/server/raft_hashicorp.go
@@ -21,8 +21,9 @@ import (
 )
 
 const (
-	ldbFile = "logs.dat"
-	sdbFile = "stable.dat"
+	ldbFile            = "logs.dat"
+	sdbFile            = "stable.dat"
+	updatePeersTimeout = 15 * time.Minute
 )
 
 func getPeerIdx(self pb.ServerAddress, mapPeers map[string]pb.ServerAddress) int {
@@ -84,7 +85,9 @@ func (s *RaftServer) UpdatePeers() {
 					s.RaftHashicorp.RemoveServer(raft.ServerID(peerLeader), 0, 0)
 				}
 			}
-			break
+			return
+		case <-time.After(updatePeersTimeout):
+			return
 		}
 	}
 }