From aad8cc9bb735c901a0aa0e818042ecc84ec1959b Mon Sep 17 00:00:00 2001
From: Sheya Bernstein <sheyaberns@gmail.com>
Date: Sun, 11 Jan 2026 00:15:16 +0000
Subject: [PATCH] fix: add filer fallback after consecutive connection failures

---
 weed/cluster/lock_client.go | 39 +++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/weed/cluster/lock_client.go b/weed/cluster/lock_client.go
index b08e8f458..241c583ea 100644
--- a/weed/cluster/lock_client.go
+++ b/weed/cluster/lock_client.go
@@ -32,17 +32,18 @@ func NewLockClient(grpcDialOption grpc.DialOption, seedFiler pb.ServerAddress) *
 }
 
 type LiveLock struct {
-	key            string
-	renewToken     string
-	expireAtNs     int64
-	hostFiler      pb.ServerAddress
-	cancelCh       chan struct{}
-	grpcDialOption grpc.DialOption
-	isLocked       int32 // 0 = unlocked, 1 = locked; use atomic operations
-	self           string
-	lc             *LockClient
-	owner          string
-	lockTTL        time.Duration
+	key                string
+	renewToken         string
+	expireAtNs         int64
+	hostFiler          pb.ServerAddress
+	cancelCh           chan struct{}
+	grpcDialOption     grpc.DialOption
+	isLocked           int32 // 0 = unlocked, 1 = locked; use atomic operations
+	self               string
+	lc                 *LockClient
+	owner              string
+	lockTTL            time.Duration
+	consecutiveFailures int // Track connection failures to trigger fallback
 }
 
 // NewShortLivedLock creates a lock with a 5-second duration
@@ -213,6 +214,7 @@ func (lock *LiveLock) doLock(lockDuration time.Duration) (errorMessage string, e
 		glog.V(4).Infof("LOCK: DistributedLock response - key=%s err=%v", lock.key, err)
 		if err == nil && resp != nil {
 			lock.renewToken = resp.RenewToken
+			lock.consecutiveFailures = 0 // Reset failure counter on success
 			glog.V(4).Infof("LOCK: Got renewToken for key=%s", lock.key)
 		} else {
 			//this can be retried. Need to remember the last valid renewToken
@@ -225,7 +227,7 @@ func (lock *LiveLock) doLock(lockDuration time.Duration) (errorMessage string, e
 				// Only log if the host actually changed
 				glog.V(2).Infof("LOCK: Host changed from %s to %s for key=%s", previousHostFiler, resp.LockHostMovedTo, lock.key)
 				lock.hostFiler = pb.ServerAddress(resp.LockHostMovedTo)
-				lock.lc.seedFiler = lock.hostFiler
+				// Don't update seedFiler - keep original for fallback
 			} else if resp.LockHostMovedTo != "" {
 				lock.hostFiler = pb.ServerAddress(resp.LockHostMovedTo)
 			}
@@ -242,6 +244,19 @@ func (lock *LiveLock) doLock(lockDuration time.Duration) (errorMessage string, e
 		}
 		return err
 	})
+
+	if err != nil && lock.hostFiler != lock.lc.seedFiler {
+		lock.consecutiveFailures++
+		// Fall back to seed filer after 3 consecutive connection failures
+		if lock.consecutiveFailures >= 3 {
+			glog.V(0).Infof("LOCK: Connection failed %d times for key=%s filer=%s, falling back to seed filer=%s",
+				lock.consecutiveFailures, lock.key, lock.hostFiler, lock.lc.seedFiler)
+			lock.hostFiler = lock.lc.seedFiler
+			lock.consecutiveFailures = 0
+			lock.renewToken = ""
+		}
+	}
+
 	return
 }