package shell import ( "cmp" "flag" "fmt" "io" "os" "time" "github.com/seaweedfs/seaweedfs/weed/pb" "github.com/seaweedfs/seaweedfs/weed/storage/erasure_coding" "github.com/seaweedfs/seaweedfs/weed/storage/super_block" "github.com/seaweedfs/seaweedfs/weed/storage/types" "golang.org/x/exp/slices" "github.com/seaweedfs/seaweedfs/weed/pb/master_pb" "github.com/seaweedfs/seaweedfs/weed/storage/needle" ) func init() { Commands = append(Commands, &commandVolumeBalance{}) } type commandVolumeBalance struct { } func (c *commandVolumeBalance) Name() string { return "volume.balance" } func (c *commandVolumeBalance) Help() string { return `balance all volumes among volume servers volume.balance [-collection ALL_COLLECTIONS|EACH_COLLECTION|] [-force] [-dataCenter=] Algorithm: For each type of volume server (different max volume count limit){ for each collection { balanceWritableVolumes() balanceReadOnlyVolumes() } } func balanceWritableVolumes(){ idealWritableVolumeRatio = totalWritableVolumes / totalNumberOfMaxVolumes for hasMovedOneVolume { sort all volume servers ordered by the localWritableVolumeRatio = localWritableVolumes to localVolumeMax pick the volume server B with the highest localWritableVolumeRatio y for any the volume server A with the number of writable volumes x + 1 <= idealWritableVolumeRatio * localVolumeMax { if y > localWritableVolumeRatio { if B has a writable volume id v that A does not have, and satisfy v replication requirements { move writable volume v from A to B } } } } } func balanceReadOnlyVolumes(){ //similar to balanceWritableVolumes } ` } func (c *commandVolumeBalance) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) { balanceCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError) collection := balanceCommand.String("collection", "ALL_COLLECTIONS", "collection name, or use \"ALL_COLLECTIONS\" across collections, \"EACH_COLLECTION\" for each collection") dc := balanceCommand.String("dataCenter", "", "only apply the balancing for this dataCenter") applyBalancing := balanceCommand.Bool("force", false, "apply the balancing plan.") if err = balanceCommand.Parse(args); err != nil { return nil } infoAboutSimulationMode(writer, *applyBalancing, "-force") if err = commandEnv.confirmIsLocked(args); err != nil { return } // collect topology information topologyInfo, _, err := collectTopologyInfo(commandEnv, 15*time.Second) if err != nil { return err } volumeServers := collectVolumeServersByDc(topologyInfo, *dc) volumeReplicas, _ := collectVolumeReplicaLocations(topologyInfo) diskTypes := collectVolumeDiskTypes(topologyInfo) if *collection == "EACH_COLLECTION" { collections, err := ListCollectionNames(commandEnv, true, false) if err != nil { return err } for _, c := range collections { if err = balanceVolumeServers(commandEnv, diskTypes, volumeReplicas, volumeServers, c, *applyBalancing); err != nil { return err } } } else { if err = balanceVolumeServers(commandEnv, diskTypes, volumeReplicas, volumeServers, *collection, *applyBalancing); err != nil { return err } } return nil } func balanceVolumeServers(commandEnv *CommandEnv, diskTypes []types.DiskType, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, collection string, applyBalancing bool) error { for _, diskType := range diskTypes { if err := balanceVolumeServersByDiskType(commandEnv, diskType, volumeReplicas, nodes, collection, applyBalancing); err != nil { return err } } return nil } func balanceVolumeServersByDiskType(commandEnv *CommandEnv, diskType types.DiskType, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, collection string, applyBalancing bool) error { for _, n := range nodes { n.selectVolumes(func(v *master_pb.VolumeInformationMessage) bool { if collection != "ALL_COLLECTIONS" { if v.Collection != collection { return false } } return v.DiskType == string(diskType) }) } if err := balanceSelectedVolume(commandEnv, diskType, volumeReplicas, nodes, sortWritableVolumes, applyBalancing); err != nil { return err } return nil } func collectVolumeServersByDc(t *master_pb.TopologyInfo, selectedDataCenter string) (nodes []*Node) { for _, dc := range t.DataCenterInfos { if selectedDataCenter != "" && dc.Id != selectedDataCenter { continue } for _, r := range dc.RackInfos { for _, dn := range r.DataNodeInfos { nodes = append(nodes, &Node{ info: dn, dc: dc.Id, rack: r.Id, }) } } } return } func collectVolumeDiskTypes(t *master_pb.TopologyInfo) (diskTypes []types.DiskType) { knownTypes := make(map[string]bool) for _, dc := range t.DataCenterInfos { for _, r := range dc.RackInfos { for _, dn := range r.DataNodeInfos { for diskType := range dn.DiskInfos { if _, found := knownTypes[diskType]; !found { knownTypes[diskType] = true } } } } } for diskType := range knownTypes { diskTypes = append(diskTypes, types.ToDiskType(diskType)) } return } type Node struct { info *master_pb.DataNodeInfo selectedVolumes map[uint32]*master_pb.VolumeInformationMessage dc string rack string } type CapacityFunc func(*master_pb.DataNodeInfo) float64 func capacityByMaxVolumeCount(diskType types.DiskType) CapacityFunc { return func(info *master_pb.DataNodeInfo) float64 { diskInfo, found := info.DiskInfos[string(diskType)] if !found { return 0 } return float64(diskInfo.MaxVolumeCount) } } func capacityByFreeVolumeCount(diskType types.DiskType) CapacityFunc { return func(info *master_pb.DataNodeInfo) float64 { diskInfo, found := info.DiskInfos[string(diskType)] if !found { return 0 } var ecShardCount int for _, ecShardInfo := range diskInfo.EcShardInfos { ecShardCount += erasure_coding.ShardBits(ecShardInfo.EcIndexBits).ShardIdCount() } return float64(diskInfo.MaxVolumeCount-diskInfo.VolumeCount) - float64(ecShardCount)/erasure_coding.DataShardsCount } } func (n *Node) localVolumeRatio(capacityFunc CapacityFunc) float64 { return float64(len(n.selectedVolumes)) / capacityFunc(n.info) } func (n *Node) localVolumeNextRatio(capacityFunc CapacityFunc) float64 { return float64(len(n.selectedVolumes)+1) / capacityFunc(n.info) } func (n *Node) isOneVolumeOnly() bool { if len(n.selectedVolumes) != 1 { return false } for _, disk := range n.info.DiskInfos { if disk.VolumeCount == 1 && disk.MaxVolumeCount == 1 { return true } } return false } func (n *Node) selectVolumes(fn func(v *master_pb.VolumeInformationMessage) bool) { n.selectedVolumes = make(map[uint32]*master_pb.VolumeInformationMessage) for _, diskInfo := range n.info.DiskInfos { for _, v := range diskInfo.VolumeInfos { if fn(v) { n.selectedVolumes[v.Id] = v } } } } func sortWritableVolumes(volumes []*master_pb.VolumeInformationMessage) { slices.SortFunc(volumes, func(a, b *master_pb.VolumeInformationMessage) int { return cmp.Compare(a.Size, b.Size) }) } func balanceSelectedVolume(commandEnv *CommandEnv, diskType types.DiskType, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, sortCandidatesFn func(volumes []*master_pb.VolumeInformationMessage), applyBalancing bool) (err error) { selectedVolumeCount, volumeMaxCount := 0, float64(0) var nodesWithCapacity []*Node capacityFunc := capacityByMaxVolumeCount(diskType) for _, dn := range nodes { selectedVolumeCount += len(dn.selectedVolumes) capacity := capacityFunc(dn.info) if capacity > 0 { nodesWithCapacity = append(nodesWithCapacity, dn) } volumeMaxCount += capacity } idealVolumeRatio := float64(selectedVolumeCount) / volumeMaxCount hasMoved := true // fmt.Fprintf(os.Stdout, " total %d volumes, max %d volumes, idealVolumeRatio %f\n", selectedVolumeCount, volumeMaxCount, idealVolumeRatio) for hasMoved { hasMoved = false slices.SortFunc(nodesWithCapacity, func(a, b *Node) int { return cmp.Compare(a.localVolumeRatio(capacityFunc), b.localVolumeRatio(capacityFunc)) }) if len(nodesWithCapacity) == 0 { fmt.Printf("no volume server found with capacity for %s", diskType.ReadableString()) return nil } var fullNode *Node var fullNodeIndex int for fullNodeIndex = len(nodesWithCapacity) - 1; fullNodeIndex >= 0; fullNodeIndex-- { fullNode = nodesWithCapacity[fullNodeIndex] if !fullNode.isOneVolumeOnly() { break } } var candidateVolumes []*master_pb.VolumeInformationMessage for _, v := range fullNode.selectedVolumes { candidateVolumes = append(candidateVolumes, v) } sortCandidatesFn(candidateVolumes) for _, emptyNode := range nodesWithCapacity[:fullNodeIndex] { if !(fullNode.localVolumeRatio(capacityFunc) > idealVolumeRatio && emptyNode.localVolumeNextRatio(capacityFunc) <= idealVolumeRatio) { // no more volume servers with empty slots break } fmt.Fprintf(os.Stdout, "%s %.2f %.2f:%.2f\t", diskType.ReadableString(), idealVolumeRatio, fullNode.localVolumeRatio(capacityFunc), emptyNode.localVolumeNextRatio(capacityFunc)) hasMoved, err = attemptToMoveOneVolume(commandEnv, volumeReplicas, fullNode, candidateVolumes, emptyNode, applyBalancing) if err != nil { return } if hasMoved { // moved one volume break } } } return nil } func attemptToMoveOneVolume(commandEnv *CommandEnv, volumeReplicas map[uint32][]*VolumeReplica, fullNode *Node, candidateVolumes []*master_pb.VolumeInformationMessage, emptyNode *Node, applyBalancing bool) (hasMoved bool, err error) { for _, v := range candidateVolumes { hasMoved, err = maybeMoveOneVolume(commandEnv, volumeReplicas, fullNode, v, emptyNode, applyBalancing) if err != nil { return } if hasMoved { break } } return } func maybeMoveOneVolume(commandEnv *CommandEnv, volumeReplicas map[uint32][]*VolumeReplica, fullNode *Node, candidateVolume *master_pb.VolumeInformationMessage, emptyNode *Node, applyChange bool) (hasMoved bool, err error) { if !commandEnv.isLocked() { return false, fmt.Errorf("lock is lost") } if candidateVolume.RemoteStorageName != "" { return false, fmt.Errorf("does not move volume in remove storage") } if candidateVolume.ReplicaPlacement > 0 { replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(candidateVolume.ReplicaPlacement)) if !isGoodMove(replicaPlacement, volumeReplicas[candidateVolume.Id], fullNode, emptyNode) { return false, nil } } if _, found := emptyNode.selectedVolumes[candidateVolume.Id]; !found { if err = moveVolume(commandEnv, candidateVolume, fullNode, emptyNode, applyChange); err == nil { adjustAfterMove(candidateVolume, volumeReplicas, fullNode, emptyNode) return true, nil } else { return } } return } func moveVolume(commandEnv *CommandEnv, v *master_pb.VolumeInformationMessage, fullNode *Node, emptyNode *Node, applyChange bool) error { collectionPrefix := v.Collection + "_" if v.Collection == "" { collectionPrefix = "" } fmt.Fprintf(os.Stdout, " moving %s volume %s%d %s => %s\n", v.DiskType, collectionPrefix, v.Id, fullNode.info.Id, emptyNode.info.Id) if applyChange { return LiveMoveVolume(commandEnv.option.GrpcDialOption, os.Stderr, needle.VolumeId(v.Id), pb.NewServerAddressFromDataNode(fullNode.info), pb.NewServerAddressFromDataNode(emptyNode.info), 5*time.Second, v.DiskType, 0, false) } return nil } func isGoodMove(placement *super_block.ReplicaPlacement, existingReplicas []*VolumeReplica, sourceNode, targetNode *Node) bool { for _, replica := range existingReplicas { if replica.location.dataNode.Id == targetNode.info.Id && replica.location.rack == targetNode.rack && replica.location.dc == targetNode.dc { // never move to existing nodes return false } } // existing replicas except the one on sourceNode existingReplicasExceptSourceNode := make([]*VolumeReplica, 0) for _, replica := range existingReplicas { if replica.location.dataNode.Id != sourceNode.info.Id { existingReplicasExceptSourceNode = append(existingReplicasExceptSourceNode, replica) } } // target location targetLocation := location{ dc: targetNode.dc, rack: targetNode.rack, dataNode: targetNode.info, } // check if this satisfies replication requirements return satisfyReplicaPlacement(placement, existingReplicasExceptSourceNode, targetLocation) } func adjustAfterMove(v *master_pb.VolumeInformationMessage, volumeReplicas map[uint32][]*VolumeReplica, fullNode *Node, emptyNode *Node) { delete(fullNode.selectedVolumes, v.Id) if emptyNode.selectedVolumes != nil { emptyNode.selectedVolumes[v.Id] = v } existingReplicas := volumeReplicas[v.Id] for _, replica := range existingReplicas { if replica.location.dataNode.Id == fullNode.info.Id && replica.location.rack == fullNode.rack && replica.location.dc == fullNode.dc { loc := newLocation(emptyNode.dc, emptyNode.rack, emptyNode.info) replica.location = &loc for diskType, diskInfo := range fullNode.info.DiskInfos { if diskType == v.DiskType { diskInfo.VolumeCount-- diskInfo.FreeVolumeCount++ } } for diskType, diskInfo := range emptyNode.info.DiskInfos { if diskType == v.DiskType { diskInfo.VolumeCount++ diskInfo.FreeVolumeCount-- } } return } } }