Avoid metadata update for incoming replication failure (#12054)

This is an optimization to save IOPS. The replication
failures will be re-queued once more to re-attempt
replication. If it still does not succeed, the replication
status is set as `FAILED` and will be caught up on
scanner cycle.

cmd/bucket-replication.go

@@ -571,7 +571,8 @@ func getReplicationAction(oi1 ObjectInfo, oi2 minio.ObjectInfo) replicationActio
 
 // replicateObject replicates the specified version of the object to destination bucket
 // The source object is then updated to reflect the replication status.
-func replicateObject(ctx context.Context, objInfo ObjectInfo, objectAPI ObjectLayer) {
+func replicateObject(ctx context.Context, ri ReplicateObjectInfo, objectAPI ObjectLayer) {
+	objInfo := ri.ObjectInfo
 	bucket := objInfo.Bucket
 	object := objInfo.Name
 
@@ -740,7 +741,8 @@ func replicateObject(ctx context.Context, objInfo ObjectInfo, objectAPI ObjectLa
 	if !ok {
 		return
 	}
-
+	// Leave metadata in `PENDING` state if inline replication fails to save iops
+	if ri.OpType == replication.HealReplicationType || replicationStatus == replication.Completed {
 		// This lower level implementation is necessary to avoid write locks from CopyObject.
 		poolIdx, err := z.getPoolIdx(ctx, bucket, object, objInfo.Size)
 		if err != nil {
@@ -756,7 +758,6 @@ func replicateObject(ctx context.Context, objInfo ObjectInfo, objectAPI ObjectLa
 				logger.LogIf(ctx, fmt.Errorf("Unable to update replication metadata for %s/%s(%s): %w", bucket, objInfo.Name, objInfo.VersionID, err))
 			}
 		}
-
 		opType := replication.MetadataReplicationType
 		if rtype == replicateAll {
 			opType = replication.ObjectReplicationType
@@ -768,6 +769,14 @@ func replicateObject(ctx context.Context, objInfo ObjectInfo, objectAPI ObjectLa
 			Object:     objInfo,
 			Host:       "Internal: [Replication]",
 		})
+	}
+	// re-queue failures once more - keep a retry count to avoid flooding the queue if
+	// the target site is down. Leave it to scanner to catch up instead.
+	if replicationStatus == replication.Failed && ri.RetryCount < 1 {
+		ri.OpType = replication.HealReplicationType
+		ri.RetryCount++
+		globalReplicationPool.queueReplicaTask(ctx, ri)
+	}
 }
 
 // filterReplicationStatusMetadata filters replication status metadata for COPY
@@ -808,9 +817,9 @@ var (
 type ReplicationPool struct {
 	mu                 sync.Mutex
 	size               int
-	replicaCh          chan ObjectInfo
+	replicaCh          chan ReplicateObjectInfo
 	replicaDeleteCh    chan DeletedObjectVersionInfo
-	mrfReplicaCh       chan ObjectInfo
+	mrfReplicaCh       chan ReplicateObjectInfo
 	mrfReplicaDeleteCh chan DeletedObjectVersionInfo
 	killCh             chan struct{}
 	wg                 sync.WaitGroup
@@ -821,9 +830,9 @@ type ReplicationPool struct {
 // NewReplicationPool creates a pool of replication workers of specified size
 func NewReplicationPool(ctx context.Context, o ObjectLayer, sz int) *ReplicationPool {
 	pool := &ReplicationPool{
-		replicaCh:          make(chan ObjectInfo, 1000),
+		replicaCh:          make(chan ReplicateObjectInfo, 1000),
 		replicaDeleteCh:    make(chan DeletedObjectVersionInfo, 1000),
-		mrfReplicaCh:       make(chan ObjectInfo, 100000),
+		mrfReplicaCh:       make(chan ReplicateObjectInfo, 100000),
 		mrfReplicaDeleteCh: make(chan DeletedObjectVersionInfo, 100000),
 		ctx:                ctx,
 		objLayer:           o,
@@ -895,7 +904,7 @@ func (p *ReplicationPool) Resize(n int) {
 	}
 }
 
-func (p *ReplicationPool) queueReplicaTask(ctx context.Context, oi ObjectInfo) {
+func (p *ReplicationPool) queueReplicaTask(ctx context.Context, ri ReplicateObjectInfo) {
 	if p == nil {
 		return
 	}
@@ -903,8 +912,8 @@ func (p *ReplicationPool) queueReplicaTask(ctx context.Context, oi ObjectInfo) {
 	case <-ctx.Done():
 		close(p.replicaCh)
 		close(p.mrfReplicaCh)
-	case p.replicaCh <- oi:
+	case p.replicaCh <- ri:
-	case p.mrfReplicaCh <- oi:
+	case p.mrfReplicaCh <- ri:
 		// queue all overflows into the mrfReplicaCh to handle incoming pending/failed operations
 	default:
 	}
@@ -1065,9 +1074,9 @@ func proxyHeadToReplicationTarget(ctx context.Context, bucket, object string, op
 
 func scheduleReplication(ctx context.Context, objInfo ObjectInfo, o ObjectLayer, sync bool, opType replication.Type) {
 	if sync {
-		replicateObject(ctx, objInfo, o)
+		replicateObject(ctx, ReplicateObjectInfo{ObjectInfo: objInfo, OpType: opType}, o)
 	} else {
-		globalReplicationPool.queueReplicaTask(GlobalContext, objInfo)
+		globalReplicationPool.queueReplicaTask(GlobalContext, ReplicateObjectInfo{ObjectInfo: objInfo, OpType: opType})
 	}
 	if sz, err := objInfo.GetActualSize(); err == nil {
 		globalReplicationStats.Update(objInfo.Bucket, sz, objInfo.ReplicationStatus, replication.StatusType(""), opType)

cmd/data-scanner.go

@@ -1109,11 +1109,11 @@ func (i *scannerItem) healReplication(ctx context.Context, o ObjectLayer, oi Obj
 	case replication.Pending:
 		sizeS.pendingCount++
 		sizeS.pendingSize += oi.Size
-		globalReplicationPool.queueReplicaTask(ctx, oi)
+		globalReplicationPool.queueReplicaTask(ctx, ReplicateObjectInfo{ObjectInfo: oi, OpType: replication.HealReplicationType})
 	case replication.Failed:
 		sizeS.failedSize += oi.Size
 		sizeS.failedCount++
-		globalReplicationPool.queueReplicaTask(ctx, oi)
+		globalReplicationPool.queueReplicaTask(ctx, ReplicateObjectInfo{ObjectInfo: oi, OpType: replication.HealReplicationType})
 	case replication.Completed, "COMPLETE":
 		sizeS.replicatedSize += oi.Size
 	case replication.Replica:

cmd/object-api-datatypes.go

@@ -220,6 +220,13 @@ func (o ObjectInfo) Clone() (cinfo ObjectInfo) {
 	return cinfo
 }
 
+// ReplicateObjectInfo represents object info to be replicated
+type ReplicateObjectInfo struct {
+	ObjectInfo
+	OpType     replication.Type
+	RetryCount uint32
+}
+
 // MultipartInfo captures metadata information about the uploadId
 // this data structure is used primarily for some internal purposes
 // for verifying upload type such as was the upload

pkg/bucket/replication/replication.go

@@ -122,6 +122,7 @@ const (
 	ObjectReplicationType Type = 1 + iota
 	DeleteReplicationType
 	MetadataReplicationType
+	HealReplicationType
 )
 
 // ObjectOpts provides information to deduce whether replication