package shell import ( "context" "fmt" "io" "math/rand" "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 file all under-replicated volumes, and find 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 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 quick 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 replicatedVolumeLocations := make(map[uint32][]location) replicatedVolumeInfo := make(map[uint32]*master_pb.VolumeInformationMessage) 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 { if v.ReplicaPlacement > 0 { replicatedVolumeLocations[v.Id] = append(replicatedVolumeLocations[v.Id], loc) replicatedVolumeInfo[v.Id] = v } } allLocations = append(allLocations, loc) }) // find all under replicated volumes underReplicatedVolumeLocations := make(map[uint32][]location) for vid, locations := range replicatedVolumeLocations { volumeInfo := replicatedVolumeInfo[vid] replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(volumeInfo.ReplicaPlacement)) if replicaPlacement.GetCopyCount() > len(locations) { underReplicatedVolumeLocations[vid] = locations } } if len(underReplicatedVolumeLocations) == 0 { return fmt.Errorf("no under replicated volumes") } if len(allLocations) == 0 { return fmt.Errorf("no data nodes at all") } // find the most under populated data nodes keepDataNodesSorted(allLocations) for vid, locations := range underReplicatedVolumeLocations { volumeInfo := replicatedVolumeInfo[vid] replicaPlacement, _ := super_block.NewReplicaPlacementFromByte(byte(volumeInfo.ReplicaPlacement)) foundNewLocation := false for _, dst := range allLocations { // check whether data nodes satisfy the constraints if dst.dataNode.FreeVolumeCount > 0 && satisfyReplicaPlacement(replicaPlacement, locations, dst) { // ask the volume server to replicate the volume sourceNodes := underReplicatedVolumeLocations[vid] sourceNode := sourceNodes[rand.Intn(len(sourceNodes))] foundNewLocation = true fmt.Fprintf(writer, "replicating volume %d %s from %s to dataNode %s ...\n", volumeInfo.Id, replicaPlacement, sourceNode.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: volumeInfo.Id, SourceDataNode: sourceNode.dataNode.Id, }) return replicateErr }) 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", volumeInfo.Id, replicaPlacement, locations) } } 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, existingLocations []location, possibleLocation location) bool { existingDataNodes := make(map[string]int) for _, loc := range existingLocations { existingDataNodes[loc.String()] += 1 } sameDataNodeCount := existingDataNodes[possibleLocation.String()] // avoid duplicated volume on the same data node if sameDataNodeCount > 0 { return false } existingDataCenters := make(map[string]int) for _, loc := range existingLocations { existingDataCenters[loc.DataCenter()] += 1 } 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 existingRacks := make(map[string]int) for _, loc := range existingLocations { if loc.DataCenter() != possibleLocation.DataCenter() { continue } existingRacks[loc.Rack()] += 1 } primaryRacks, _ := findTopKeys(existingRacks) sameRackCount := existingRacks[possibleLocation.Rack()] // ensure rack count is within limit if _, found := existingRacks[possibleLocation.Rack()]; !found { // different from existing racks if len(existingRacks) < 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 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 }