package shell import ( "context" "fmt" "github.com/chrislusf/seaweedfs/weed/storage/needle" "io" "sort" "github.com/chrislusf/seaweedfs/weed/operation" "github.com/chrislusf/seaweedfs/weed/pb/master_pb" "github.com/chrislusf/seaweedfs/weed/pb/volume_server_pb" "github.com/chrislusf/seaweedfs/weed/storage/super_block" ) func init() { Commands = append(Commands, &commandVolumeFixReplication{}) } type commandVolumeFixReplication struct { } func (c *commandVolumeFixReplication) Name() string { return "volume.fix.replication" } func (c *commandVolumeFixReplication) Help() string { return `add replicas to volumes that are missing replicas This command finds all over-replicated volumes. If found, it will purge the oldest copies and stop. This command also finds all under-replicated volumes, and finds volume servers with free slots. If the free slots satisfy the replication requirement, the volume content is copied over and mounted. volume.fix.replication -n # do not take action volume.fix.replication # actually deleting or copying the volume files and mount the volume Note: * each time this will only add back one replica for one volume id. If there are multiple replicas are missing, e.g. multiple volume servers are new, you may need to run this multiple times. * do not run this too quickly within seconds, since the new volume replica may take a few seconds to register itself to the master. ` } func (c *commandVolumeFixReplication) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) { if err = commandEnv.confirmIsLocked(); err != nil { return } takeAction := true if len(args) > 0 && args[0] == "-n" { takeAction = false } var resp *master_pb.VolumeListResponse err = commandEnv.MasterClient.WithClient(func(client master_pb.SeaweedClient) error { resp, err = client.VolumeList(context.Background(), &master_pb.VolumeListRequest{}) return err }) if err != nil { return err } // find all volumes that needs replication // collect all data nodes volumeReplicas := make(map[uint32][]*VolumeReplica) var allLocations []location eachDataNode(resp.TopologyInfo, func(dc string, rack RackId, dn *master_pb.DataNodeInfo) { loc := newLocation(dc, string(rack), dn) for _, v := range dn.VolumeInfos { volumeReplicas[v.Id] = append(volumeReplicas[v.Id], &VolumeReplica{ location: &loc, info: v, }) } allLocations = append(allLocations, loc) }) if len(allLocations) == 0 { return fmt.Errorf("no data nodes at all") } // 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(overReplicatedVolumeIds) > 0 { return c.fixOverReplicatedVolumes(commandEnv, writer, takeAction, overReplicatedVolumeIds, volumeReplicas, allLocations) } if len(underReplicatedVolumeIds) == 0 { return nil } // find the most under populated data nodes keepDataNodesSorted(allLocations) return c.fixUnderReplicatedVolumes(commandEnv, writer, takeAction, underReplicatedVolumeIds, volumeReplicas, allLocations) } func (c *commandVolumeFixReplication) fixOverReplicatedVolumes(commandEnv *CommandEnv, writer io.Writer, takeAction bool, overReplicatedVolumeIds []uint32, volumeReplicas map[uint32][]*VolumeReplica, allLocations []location) error { for _, vid := range overReplicatedVolumeIds { replicas := volumeReplicas[vid] replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(replicas[0].info.ReplicaPlacement)) replica := pickOneReplicaToDelete(replicas, replicaPlacement) fmt.Fprintf(writer, "deleting volume %d from %s ...\n", replica.info.Id, replica.location.dataNode.Id) if !takeAction { break } if err := deleteVolume(commandEnv.option.GrpcDialOption, needle.VolumeId(replica.info.Id), replica.location.dataNode.Id); err != nil { return fmt.Errorf("deleting volume %d from %s : %v", replica.info.Id, replica.location.dataNode.Id, err) } } return nil } func (c *commandVolumeFixReplication) fixUnderReplicatedVolumes(commandEnv *CommandEnv, writer io.Writer, takeAction bool, underReplicatedVolumeIds []uint32, volumeReplicas map[uint32][]*VolumeReplica, allLocations []location) error { for _, vid := range underReplicatedVolumeIds { replicas := volumeReplicas[vid] replica := pickOneReplicaToCopyFrom(replicas) replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(replica.info.ReplicaPlacement)) foundNewLocation := false for _, dst := range allLocations { // check whether data nodes satisfy the constraints if dst.dataNode.FreeVolumeCount > 0 && satisfyReplicaPlacement(replicaPlacement, replicas, dst) { // ask the volume server to replicate the volume foundNewLocation = true fmt.Fprintf(writer, "replicating volume %d %s from %s to dataNode %s ...\n", replica.info.Id, replicaPlacement, replica.location.dataNode.Id, dst.dataNode.Id) if !takeAction { break } err := operation.WithVolumeServerClient(dst.dataNode.Id, commandEnv.option.GrpcDialOption, func(volumeServerClient volume_server_pb.VolumeServerClient) error { _, replicateErr := volumeServerClient.VolumeCopy(context.Background(), &volume_server_pb.VolumeCopyRequest{ VolumeId: replica.info.Id, SourceDataNode: replica.location.dataNode.Id, }) if replicateErr != nil { return fmt.Errorf("copying from %s => %s : %v", replica.location.dataNode.Id, dst.dataNode.Id, replicateErr) } return nil }) if err != nil { return err } // adjust free volume count dst.dataNode.FreeVolumeCount-- keepDataNodesSorted(allLocations) break } } if !foundNewLocation { fmt.Fprintf(writer, "failed to place volume %d replica as %s, existing:%+v\n", replica.info.Id, replicaPlacement, len(replicas)) } } return nil } func keepDataNodesSorted(dataNodes []location) { sort.Slice(dataNodes, func(i, j int) bool { return dataNodes[i].dataNode.FreeVolumeCount > dataNodes[j].dataNode.FreeVolumeCount }) } /* if on an existing data node { return false } if different from existing dcs { if lack on different dcs { return true }else{ return false } } if not on primary dc { return false } if different from existing racks { if lack on different racks { return true }else{ return false } } if not on primary rack { return false } if lacks on same rack { return true } else { return false } */ func satisfyReplicaPlacement(replicaPlacement *super_block.ReplicaPlacement, replicas []*VolumeReplica, possibleLocation location) bool { existingDataCenters, _, existingDataNodes := countReplicas(replicas) if _, found := existingDataNodes[possibleLocation.String()]; found { // avoid duplicated volume on the same data node return false } primaryDataCenters, _ := findTopKeys(existingDataCenters) // ensure data center count is within limit if _, found := existingDataCenters[possibleLocation.DataCenter()]; !found { // different from existing dcs if len(existingDataCenters) < replicaPlacement.DiffDataCenterCount+1 { // lack on different dcs return true } else { // adding this would go over the different dcs limit return false } } // now this is same as one of the existing data center if !isAmong(possibleLocation.DataCenter(), primaryDataCenters) { // not on one of the primary dcs return false } // now this is one of the primary dcs primaryDcRacks := make(map[string]int) for _, replica := range replicas { if replica.location.DataCenter() != possibleLocation.DataCenter() { continue } primaryDcRacks[replica.location.Rack()] += 1 } primaryRacks, _ := findTopKeys(primaryDcRacks) sameRackCount := primaryDcRacks[possibleLocation.Rack()] // ensure rack count is within limit if _, found := primaryDcRacks[possibleLocation.Rack()]; !found { // different from existing racks if len(primaryDcRacks) < replicaPlacement.DiffRackCount+1 { // lack on different racks return true } else { // adding this would go over the different racks limit return false } } // now this is same as one of the existing racks if !isAmong(possibleLocation.Rack(), primaryRacks) { // not on the primary rack return false } // now this is on the primary rack // different from existing data nodes if sameRackCount < replicaPlacement.SameRackCount+1 { // lack on same rack return true } else { // adding this would go over the same data node limit return false } } func findTopKeys(m map[string]int) (topKeys []string, max int) { for k, c := range m { if max < c { topKeys = topKeys[:0] topKeys = append(topKeys, k) max = c } else if max == c { topKeys = append(topKeys, k) } } return } func isAmong(key string, keys []string) bool { for _, k := range keys { if k == key { return true } } return false } type VolumeReplica struct { location *location info *master_pb.VolumeInformationMessage } type location struct { dc string rack string dataNode *master_pb.DataNodeInfo } func newLocation(dc, rack string, dataNode *master_pb.DataNodeInfo) location { return location{ dc: dc, rack: rack, dataNode: dataNode, } } func (l location) String() string { return fmt.Sprintf("%s %s %s", l.dc, l.rack, l.dataNode.Id) } func (l location) Rack() string { return fmt.Sprintf("%s %s", l.dc, l.rack) } func (l location) DataCenter() string { return l.dc } func pickOneReplicaToCopyFrom(replicas []*VolumeReplica) *VolumeReplica { mostRecent := replicas[0] for _, replica := range replicas { if replica.info.ModifiedAtSecond > mostRecent.info.ModifiedAtSecond { mostRecent = replica } } return mostRecent } func countReplicas(replicas []*VolumeReplica) (diffDc, diffRack, diffNode map[string]int) { diffDc = make(map[string]int) diffRack = make(map[string]int) diffNode = make(map[string]int) for _, replica := range replicas { diffDc[replica.location.DataCenter()] += 1 diffRack[replica.location.Rack()] += 1 diffNode[replica.location.String()] += 1 } return } func pickOneReplicaToDelete(replicas []*VolumeReplica, replicaPlacement *super_block.ReplicaPlacement) *VolumeReplica { allSame := true oldest := replicas[0] for _, replica := range replicas { if replica.info.ModifiedAtSecond < oldest.info.ModifiedAtSecond { oldest = replica allSame = false } } if !allSame { return oldest } // TODO what if all the replicas have the same timestamp? return oldest }