shell: add volumeServer.leave command

weed/Makefile

@@ -24,4 +24,4 @@ debug_server:
 
 debug_volume:
 	go build -gcflags="all=-N -l"
-	dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec weed -- volume -dir=/Volumes/mobile_disk/100 -port 8564 -max=30
+	dlv --listen=:2345 --headless=true --api-version=2 --accept-multiclient exec weed -- volume -dir=/Volumes/mobile_disk/100 -port 8564 -max=30 -preStopSeconds=2

weed/command/volume.go

@@ -223,22 +223,27 @@ func (v VolumeServerOptions) startVolumeServer(volumeFolders, maxVolumeCounts, v
 	// starting the cluster http server
 	clusterHttpServer := v.startClusterHttpService(volumeMux)
 
+	stopChan := make(chan bool)
 	grace.OnInterrupt(func() {
 		fmt.Println("volume server has be killed")
 
-		// Stop heartbeatsZ
+		// Stop heartbeats
+		if !volumeServer.StopHeartbeat() {
 			glog.V(0).Infof("stop send heartbeat and wait %d seconds until shutdown ...", *v.preStopSeconds)
-		volumeServer.SendHeartbeat = false
 			time.Sleep(time.Duration(*v.preStopSeconds) * time.Second)
+		}
 
-		v.shutdown(publicHttpDown, clusterHttpServer, grpcS, volumeServer)
+		shutdown(publicHttpDown, clusterHttpServer, grpcS, volumeServer)
+		stopChan <- true
 	})
 
-	select {}
+	select {
+	case <-stopChan:
+	}
 
 }
 
-func (v VolumeServerOptions) shutdown(publicHttpDown httpdown.Server, clusterHttpServer httpdown.Server, grpcS *grpc.Server, volumeServer *weed_server.VolumeServer) {
+func shutdown(publicHttpDown httpdown.Server, clusterHttpServer httpdown.Server, grpcS *grpc.Server, volumeServer *weed_server.VolumeServer) {
 
 	// firstly, stop the public http service to prevent from receiving new user request
 	if nil != publicHttpDown {

weed/pb/volume_server.proto

@@ -85,6 +85,8 @@ service VolumeServer {
 
     rpc VolumeServerStatus (VolumeServerStatusRequest) returns (VolumeServerStatusResponse) {
     }
+    rpc VolumeServerLeave (VolumeServerLeaveRequest) returns (VolumeServerLeaveResponse) {
+    }
 
     // <experimental> query
     rpc Query (QueryRequest) returns (stream QueriedStripe) {
@@ -425,6 +427,11 @@ message VolumeServerStatusResponse {
     MemStatus memory_status = 2;
 }
 
+message VolumeServerLeaveRequest {
+}
+message VolumeServerLeaveResponse {
+}
+
 // select on volume servers
 message QueryRequest {
     repeated string selections = 1;

weed/server/volume_grpc_admin.go

@@ -196,6 +196,16 @@ func (vs *VolumeServer) VolumeServerStatus(ctx context.Context, req *volume_serv
 
 }
 
+func (vs *VolumeServer) VolumeServerLeave(ctx context.Context, req *volume_server_pb.VolumeServerLeaveRequest) (*volume_server_pb.VolumeServerLeaveResponse, error) {
+
+	resp := &volume_server_pb.VolumeServerLeaveResponse{}
+
+	vs.StopHeartbeat()
+
+	return resp, nil
+
+}
+
 func (vs *VolumeServer) VolumeNeedleStatus(ctx context.Context, req *volume_server_pb.VolumeNeedleStatusRequest) (*volume_server_pb.VolumeNeedleStatusResponse, error) {
 
 	resp := &volume_server_pb.VolumeNeedleStatusResponse{}

weed/server/volume_grpc_client_to_master.go

@@ -31,7 +31,7 @@ func (vs *VolumeServer) heartbeat() {
 
 	var err error
 	var newLeader string
-	for {
+	for vs.isHeartbeating {
 		for _, master := range vs.SeedMasterNodes {
 			if newLeader != "" {
 				// the new leader may actually is the same master
@@ -52,9 +52,21 @@ func (vs *VolumeServer) heartbeat() {
 				newLeader = ""
 				vs.store.MasterAddress = ""
 			}
+			if !vs.isHeartbeating {
+				break
 			}
 		}
 	}
+}
+
+func (vs *VolumeServer) StopHeartbeat() (isAlreadyStopping bool) {
+	if !vs.isHeartbeating {
+		return true
+	}
+	vs.isHeartbeating = false
+	vs.stopChan <- true
+	return false
+}
 
 func (vs *VolumeServer) doHeartbeat(masterNode, masterGrpcAddress string, grpcDialOption grpc.DialOption, sleepInterval time.Duration) (newLeader string, err error) {
 
@@ -171,15 +183,11 @@ func (vs *VolumeServer) doHeartbeat(masterNode, masterGrpcAddress string, grpcDi
 				return "", err
 			}
 		case <-volumeTickChan:
-			if vs.SendHeartbeat {
 			glog.V(4).Infof("volume server %s:%d heartbeat", vs.store.Ip, vs.store.Port)
 			if err = stream.Send(vs.store.CollectHeartbeat()); err != nil {
 				glog.V(0).Infof("Volume Server Failed to talk with master %s: %v", masterNode, err)
 				return "", err
 			}
-			} else {
-				glog.V(4).Infof("volume server %s:%d skip send heartbeat", vs.store.Ip, vs.store.Port)
-			}
 		case <-ecShardTickChan:
 			glog.V(4).Infof("volume server %s:%d ec heartbeat", vs.store.Ip, vs.store.Port)
 			if err = stream.Send(vs.store.CollectErasureCodingHeartbeat()); err != nil {
@@ -188,6 +196,8 @@ func (vs *VolumeServer) doHeartbeat(masterNode, masterGrpcAddress string, grpcDi
 			}
 		case err = <-doneChan:
 			return
+		case <-vs.stopChan:
+			return
 		}
 	}
 }

weed/server/volume_server.go

@@ -31,7 +31,8 @@ type VolumeServer struct {
 	MetricsAddress          string
 	MetricsIntervalSec      int
 	fileSizeLimitBytes      int64
-	SendHeartbeat           bool
+	isHeartbeating          bool
+	stopChan                chan bool
 }
 
 func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
@@ -67,7 +68,8 @@ func NewVolumeServer(adminMux, publicMux *http.ServeMux, ip string,
 		grpcDialOption:          security.LoadClientTLS(util.GetViper(), "grpc.volume"),
 		compactionBytePerSecond: int64(compactionMBPerSecond) * 1024 * 1024,
 		fileSizeLimitBytes:      int64(fileSizeLimitMB) * 1024 * 1024,
-		SendHeartbeat:           true,
+		isHeartbeating:          true,
+		stopChan:                make(chan bool),
 	}
 	vs.SeedMasterNodes = masterNodes
 	vs.store = storage.NewStore(vs.grpcDialOption, port, ip, publicUrl, folders, maxCounts, minFreeSpacePercents, vs.needleMapKind)

weed/shell/command_volume_server_leave.go

@@ -0,0 +1,67 @@
+package shell
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/operation"
+	"github.com/chrislusf/seaweedfs/weed/pb/volume_server_pb"
+	"google.golang.org/grpc"
+	"io"
+)
+
+func init() {
+	Commands = append(Commands, &commandVolumeServerLeave{})
+}
+
+type commandVolumeServerLeave struct {
+}
+
+func (c *commandVolumeServerLeave) Name() string {
+	return "volumeServer.leave"
+}
+
+func (c *commandVolumeServerLeave) Help() string {
+	return `stop a volume server from sending heartbeats to the master
+
+	volume.unmount -node <volume server host:port> -force
+
+	This command enables gracefully shutting down the volume server.
+	The volume server will stop sending heartbeats to the master.
+	After draining the traffic for a few seconds, you can safely shut down the volume server.
+
+	This operation is not revocable unless the volume server is restarted.
+`
+}
+
+func (c *commandVolumeServerLeave) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	if err = commandEnv.confirmIsLocked(); err != nil {
+		return
+	}
+
+	vsLeaveCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+	volumeServer := vsLeaveCommand.String("node", "", "<host>:<port> of the volume server")
+	if err = vsLeaveCommand.Parse(args); err != nil {
+		return nil
+	}
+
+	if *volumeServer == "" {
+		return fmt.Errorf("need to specify volume server by -node=<host>:<port>")
+	}
+
+	return volumeServerLeave(commandEnv.option.GrpcDialOption, *volumeServer, writer)
+
+}
+
+func volumeServerLeave(grpcDialOption grpc.DialOption, volumeServer string, writer io.Writer) (err error) {
+	return operation.WithVolumeServerClient(volumeServer, grpcDialOption, func(volumeServerClient volume_server_pb.VolumeServerClient) error {
+		_, leaveErr := volumeServerClient.VolumeServerLeave(context.Background(), &volume_server_pb.VolumeServerLeaveRequest{})
+		if leaveErr != nil {
+			fmt.Fprintf(writer, "ask volume server %s to leave: %v\n", volumeServer, leaveErr)
+		} else {
+			fmt.Fprintf(writer, "stopped heartbeat in volume server %s. After a few seconds to drain traffic, it will be safe to stop the volume server.\n", volumeServer)
+		}
+		return leaveErr
+	})
+}

weed/shell/shell_liner.go

@@ -66,7 +66,7 @@ func processEachCmd(reg *regexp.Regexp, cmd string, commandEnv *CommandEnv) bool
 			args[i] = strings.Trim(string(cmds[1+i]), "\"'")
 		}
 
-		cmd := strings.ToLower(cmds[0])
+		cmd := cmds[0]
 		if cmd == "help" || cmd == "?" {
 			printHelp(cmds)
 		} else if cmd == "exit" || cmd == "quit" {