From fc51ffce2b2e07145e6c7144781a40491febd6cb Mon Sep 17 00:00:00 2001
From: Konstantin Lebedev <lebedev_k@tochka.com>
Date: Thu, 30 Sep 2021 20:24:24 +0500
Subject: [PATCH] https://github.com/chrislusf/seaweedfs/issues/1846

---
 weed/shell/command_volume_fix_replication.go | 80 ++++++++++++--------
 1 file changed, 47 insertions(+), 33 deletions(-)

diff --git a/weed/shell/command_volume_fix_replication.go b/weed/shell/command_volume_fix_replication.go
index 76a582b31..9ac082e81 100644
--- a/weed/shell/command_volume_fix_replication.go
+++ b/weed/shell/command_volume_fix_replication.go
@@ -56,6 +56,8 @@ func (c *commandVolumeFixReplication) Do(args []string, commandEnv *CommandEnv,
 	c.collectionPattern = volFixReplicationCommand.String("collectionPattern", "", "match with wildcard characters '*' and '?'")
 	skipChange := volFixReplicationCommand.Bool("n", false, "skip the changes")
 	retryCount := volFixReplicationCommand.Int("retry", 0, "how many times to retry")
+	volumespPerStep := volFixReplicationCommand.Int("volumes_per_step", 0, "how many volumes to fix in one cycle")
+
 	if err = volFixReplicationCommand.Parse(args); err != nil {
 		return nil
 	}
@@ -66,44 +68,54 @@ func (c *commandVolumeFixReplication) Do(args []string, commandEnv *CommandEnv,
 
 	takeAction := !*skipChange
 
-	// collect topology information
-	topologyInfo, _, err := collectTopologyInfo(commandEnv)
-	if err != nil {
-		return err
-	}
-
-	// find all volumes that needs replication
-	// collect all data nodes
-	volumeReplicas, allLocations := collectVolumeReplicaLocations(topologyInfo)
+	underReplicatedVolumeIdsCount := 1
+	for underReplicatedVolumeIdsCount > 0 {
+		// collect topology information
+		topologyInfo, _, err := collectTopologyInfo(commandEnv)
+		if err != nil {
+			return err
+		}
 
-	if len(allLocations) == 0 {
-		return fmt.Errorf("no data nodes at all")
-	}
+		// find all volumes that needs replication
+		// collect all data nodes
+		volumeReplicas, allLocations := collectVolumeReplicaLocations(topologyInfo)
 
-	// find all under replicated volumes
-	var underReplicatedVolumeIds, overReplicatedVolumeIds []uint32
-	for vid, replicas := range volumeReplicas {
-		replica := replicas[0]
-		replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(replica.info.ReplicaPlacement))
-		if replicaPlacement.GetCopyCount() > len(replicas) {
-			underReplicatedVolumeIds = append(underReplicatedVolumeIds, vid)
-		} else if replicaPlacement.GetCopyCount() < len(replicas) {
-			overReplicatedVolumeIds = append(overReplicatedVolumeIds, vid)
-			fmt.Fprintf(writer, "volume %d replication %s, but over replicated %+d\n", replica.info.Id, replicaPlacement, len(replicas))
+		if len(allLocations) == 0 {
+			return fmt.Errorf("no data nodes at all")
 		}
-	}
 
-	if len(overReplicatedVolumeIds) > 0 {
-		return c.fixOverReplicatedVolumes(commandEnv, writer, takeAction, overReplicatedVolumeIds, volumeReplicas, allLocations)
-	}
+		// find all under replicated volumes
+		var underReplicatedVolumeIds, overReplicatedVolumeIds []uint32
+		for vid, replicas := range volumeReplicas {
+			replica := replicas[0]
+			replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(replica.info.ReplicaPlacement))
+			if replicaPlacement.GetCopyCount() > len(replicas) {
+				underReplicatedVolumeIds = append(underReplicatedVolumeIds, vid)
+			} else if replicaPlacement.GetCopyCount() < len(replicas) {
+				overReplicatedVolumeIds = append(overReplicatedVolumeIds, vid)
+				fmt.Fprintf(writer, "volume %d replication %s, but over replicated %+d\n", replica.info.Id, replicaPlacement, len(replicas))
+			}
+		}
 
-	if len(underReplicatedVolumeIds) == 0 {
-		return nil
-	}
+		if len(overReplicatedVolumeIds) > 0 {
+			if err := c.fixOverReplicatedVolumes(commandEnv, writer, takeAction, overReplicatedVolumeIds, volumeReplicas, allLocations); err != nil {
+				return err
+			}
+		}
 
-	// find the most under populated data nodes
-	return c.fixUnderReplicatedVolumes(commandEnv, writer, takeAction, underReplicatedVolumeIds, volumeReplicas, allLocations, *retryCount)
+		underReplicatedVolumeIdsCount = len(underReplicatedVolumeIds)
+		if underReplicatedVolumeIdsCount > 0 {
+			// find the most under populated data nodes
+			if err := c.fixUnderReplicatedVolumes(commandEnv, writer, takeAction, underReplicatedVolumeIds, volumeReplicas, allLocations, *retryCount, *volumespPerStep); err != nil {
+				return err
+			}
+		}
 
+		if *skipChange {
+			break
+		}
+	}
+	return nil
 }
 
 func collectVolumeReplicaLocations(topologyInfo *master_pb.TopologyInfo) (map[uint32][]*VolumeReplica, []location) {
@@ -156,8 +168,10 @@ func (c *commandVolumeFixReplication) fixOverReplicatedVolumes(commandEnv *Comma
 	return nil
 }
 
-func (c *commandVolumeFixReplication) fixUnderReplicatedVolumes(commandEnv *CommandEnv, writer io.Writer, takeAction bool, underReplicatedVolumeIds []uint32, volumeReplicas map[uint32][]*VolumeReplica, allLocations []location, retryCount int) (err error) {
-
+func (c *commandVolumeFixReplication) fixUnderReplicatedVolumes(commandEnv *CommandEnv, writer io.Writer, takeAction bool, underReplicatedVolumeIds []uint32, volumeReplicas map[uint32][]*VolumeReplica, allLocations []location, retryCount int, volumespPerStep int) (err error) {
+	if len(underReplicatedVolumeIds) > volumespPerStep && volumespPerStep > 0 {
+		underReplicatedVolumeIds = underReplicatedVolumeIds[0:volumespPerStep]
+	}
 	for _, vid := range underReplicatedVolumeIds {
 		for i := 0; i < retryCount+1; i++ {
 			if err = c.fixOneUnderReplicatedVolume(commandEnv, writer, takeAction, volumeReplicas, vid, allLocations); err == nil {