less aggressive volume server shutdown on same uuid

related to https://github.com/seaweedfs/seaweedfs/issues/5439

weed/server/volume_grpc_client_to_master.go

@@ -3,6 +3,7 @@ package weed_server
 import (
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/seaweedfs/seaweedfs/weed/operation"
@@ -57,6 +58,7 @@ func (vs *VolumeServer) heartbeat() {
 
 	var err error
 	var newLeader pb.ServerAddress
+	duplicateRetryCount := 0
 	for vs.isHeartbeating {
 		for _, master := range vs.SeedMasterNodes {
 			if newLeader != "" {
@@ -66,12 +68,27 @@ func (vs *VolumeServer) heartbeat() {
 				master = newLeader
 			}
 			vs.store.MasterAddress = master
-			newLeader, err = vs.doHeartbeat(master, grpcDialOption, time.Duration(vs.pulseSeconds)*time.Second)
+			newLeader, err = vs.doHeartbeatWithRetry(master, grpcDialOption, time.Duration(vs.pulseSeconds)*time.Second, duplicateRetryCount)
 			if err != nil {
 				glog.V(0).Infof("heartbeat to %s error: %v", master, err)
+
+				// Check if this is a duplicate UUID retry error
+				if strings.Contains(err.Error(), "duplicate UUIDs detected, retrying connection") {
+					duplicateRetryCount++
+					retryDelay := time.Duration(1<<(duplicateRetryCount-1)) * 2 * time.Second // exponential backoff: 2s, 4s, 8s
+					glog.V(0).Infof("Waiting %v before retrying due to duplicate UUID detection...", retryDelay)
+					time.Sleep(retryDelay)
+				} else {
+					// Regular error, reset duplicate retry count
+					duplicateRetryCount = 0
 					time.Sleep(time.Duration(vs.pulseSeconds) * time.Second)
+				}
+
 				newLeader = ""
 				vs.store.MasterAddress = ""
+			} else {
+				// Successful connection, reset retry count
+				duplicateRetryCount = 0
 			}
 			if !vs.isHeartbeating {
 				break
@@ -90,6 +107,10 @@ func (vs *VolumeServer) StopHeartbeat() (isAlreadyStopping bool) {
 }
 
 func (vs *VolumeServer) doHeartbeat(masterAddress pb.ServerAddress, grpcDialOption grpc.DialOption, sleepInterval time.Duration) (newLeader pb.ServerAddress, err error) {
+	return vs.doHeartbeatWithRetry(masterAddress, grpcDialOption, sleepInterval, 0)
+}
+
+func (vs *VolumeServer) doHeartbeatWithRetry(masterAddress pb.ServerAddress, grpcDialOption grpc.DialOption, sleepInterval time.Duration, duplicateRetryCount int) (newLeader pb.ServerAddress, err error) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
@@ -127,9 +148,24 @@ func (vs *VolumeServer) doHeartbeat(masterAddress pb.ServerAddress, grpcDialOpti
 						}
 					}
 				}
-				glog.Errorf("Shut down Volume Server due to duplicate volume directories: %v", duplicateDir)
+
+				// Implement retry logic for potential race conditions
+				const maxRetries = 3
+				if duplicateRetryCount < maxRetries {
+					retryDelay := time.Duration(1<<duplicateRetryCount) * 2 * time.Second // exponential backoff: 2s, 4s, 8s
+					glog.Errorf("Master reported duplicate volume directories: %v (retry %d/%d)", duplicateDir, duplicateRetryCount+1, maxRetries)
+					glog.Errorf("This might be due to a race condition during reconnection. Waiting %v before retrying...", retryDelay)
+
+					// Return error to trigger retry with increased count
+					doneChan <- fmt.Errorf("duplicate UUIDs detected, retrying connection (attempt %d/%d)", duplicateRetryCount+1, maxRetries)
+					return
+				} else {
+					// After max retries, this is likely a real duplicate
+					glog.Errorf("Shut down Volume Server due to persistent duplicate volume directories after %d retries: %v", maxRetries, duplicateDir)
+					glog.Errorf("Please check if another volume server is using the same directory")
 					os.Exit(1)
 				}
+			}
 			volumeOptsChanged := false
 			if vs.store.GetPreallocate() != in.GetPreallocate() {
 				vs.store.SetPreallocate(in.GetPreallocate())