seaweedfs/weed/shell/command_volume_fix_replication.go
2020-05-17 20:27:10 -07:00

305 lines
8.3 KiB
Go

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 fmt.Errorf("copying from %s => %s : %v", sourceNode.dataNode.Id, dst.dataNode.Id, 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
}