seaweedfs/weed/shell/command_volume_balance.go
2021-08-10 02:50:28 -07:00

402 lines
12 KiB
Go

package shell
import (
"flag"
"fmt"
"github.com/chrislusf/seaweedfs/weed/storage/super_block"
"github.com/chrislusf/seaweedfs/weed/storage/types"
"io"
"os"
"sort"
"time"
"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
"github.com/chrislusf/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|EACH_COLLECTION|<collection_name>] [-force] [-dataCenter=<data_center_name>]
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) {
if err = commandEnv.confirmIsLocked(); err != nil {
return
}
balanceCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
collection := balanceCommand.String("collection", "EACH_COLLECTION", "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
}
// collect topology information
topologyInfo, volumeSizeLimitMb, err := collectTopologyInfo(commandEnv)
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, volumeSizeLimitMb*1024*1024, c, *applyBalancing); err != nil {
return err
}
}
} else if *collection == "ALL_COLLECTIONS" {
if err = balanceVolumeServers(commandEnv, diskTypes, volumeReplicas, volumeServers, volumeSizeLimitMb*1024*1024, "ALL_COLLECTIONS", *applyBalancing); err != nil {
return err
}
} else {
if err = balanceVolumeServers(commandEnv, diskTypes, volumeReplicas, volumeServers, volumeSizeLimitMb*1024*1024, *collection, *applyBalancing); err != nil {
return err
}
}
return nil
}
func balanceVolumeServers(commandEnv *CommandEnv, diskTypes []types.DiskType, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, volumeSizeLimit uint64, collection string, applyBalancing bool) error {
for _, diskType := range diskTypes {
if err := balanceVolumeServersByDiskType(commandEnv, diskType, volumeReplicas, nodes, volumeSizeLimit, collection, applyBalancing); err != nil {
return err
}
}
return nil
}
func balanceVolumeServersByDiskType(commandEnv *CommandEnv, diskType types.DiskType, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, volumeSizeLimit uint64, collection string, applyBalancing bool) error {
// balance read only volumes
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) && (v.ReadOnly || v.Size >= volumeSizeLimit)
})
}
if err := balanceSelectedVolume(commandEnv, volumeReplicas, nodes, capacityByMaxVolumeCount(diskType), sortReadOnlyVolumes, applyBalancing); err != nil {
return err
}
// balance writable volumes
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) && (!v.ReadOnly && v.Size < volumeSizeLimit)
})
}
if err := balanceSelectedVolume(commandEnv, volumeReplicas, nodes, capacityByMaxVolumeCount(diskType), 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) int
func capacityByMaxVolumeCount(diskType types.DiskType) CapacityFunc {
return func(info *master_pb.DataNodeInfo) int {
diskInfo, found := info.DiskInfos[string(diskType)]
if !found {
return 0
}
return int(diskInfo.MaxVolumeCount)
}
}
func capacityByFreeVolumeCount(diskType types.DiskType) CapacityFunc {
return func(info *master_pb.DataNodeInfo) int {
diskInfo, found := info.DiskInfos[string(diskType)]
if !found {
return 0
}
return int(diskInfo.MaxVolumeCount - diskInfo.VolumeCount)
}
}
func (n *Node) localVolumeRatio(capacityFunc CapacityFunc) float64 {
return divide(len(n.selectedVolumes), capacityFunc(n.info))
}
func (n *Node) localVolumeNextRatio(capacityFunc CapacityFunc) float64 {
return divide(len(n.selectedVolumes)+1, capacityFunc(n.info))
}
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) {
sort.Slice(volumes, func(i, j int) bool {
return volumes[i].Size < volumes[j].Size
})
}
func sortReadOnlyVolumes(volumes []*master_pb.VolumeInformationMessage) {
sort.Slice(volumes, func(i, j int) bool {
return volumes[i].Id < volumes[j].Id
})
}
func balanceSelectedVolume(commandEnv *CommandEnv, volumeReplicas map[uint32][]*VolumeReplica, nodes []*Node, capacityFunc CapacityFunc, sortCandidatesFn func(volumes []*master_pb.VolumeInformationMessage), applyBalancing bool) (err error) {
selectedVolumeCount, volumeMaxCount := 0, 0
var nodesWithCapacity []*Node
for _, dn := range nodes {
selectedVolumeCount += len(dn.selectedVolumes)
capacity := capacityFunc(dn.info)
if capacity > 0 {
nodesWithCapacity = append(nodesWithCapacity, dn)
}
volumeMaxCount += capacity
}
idealVolumeRatio := divide(selectedVolumeCount, volumeMaxCount)
hasMoved := true
// fmt.Fprintf(os.Stdout, " total %d volumes, max %d volumes, idealVolumeRatio %f\n", selectedVolumeCount, volumeMaxCount, idealVolumeRatio)
for hasMoved {
hasMoved = false
sort.Slice(nodesWithCapacity, func(i, j int) bool {
return nodesWithCapacity[i].localVolumeRatio(capacityFunc) < nodesWithCapacity[j].localVolumeRatio(capacityFunc)
})
fullNode := nodesWithCapacity[len(nodesWithCapacity)-1]
var candidateVolumes []*master_pb.VolumeInformationMessage
for _, v := range fullNode.selectedVolumes {
candidateVolumes = append(candidateVolumes, v)
}
sortCandidatesFn(candidateVolumes)
for i := 0; i < len(nodesWithCapacity)-1; i++ {
emptyNode := nodesWithCapacity[i]
if !(fullNode.localVolumeRatio(capacityFunc) > idealVolumeRatio && emptyNode.localVolumeNextRatio(capacityFunc) <= idealVolumeRatio) {
// no more volume servers with empty slots
break
}
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 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), fullNode.info.Id, emptyNode.info.Id, 5*time.Second, v.DiskType, 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
}
}
dcs, racks := make(map[string]bool), make(map[string]int)
for _, replica := range existingReplicas {
if replica.location.dataNode.Id != sourceNode.info.Id {
dcs[replica.location.DataCenter()] = true
racks[replica.location.Rack()]++
}
}
dcs[targetNode.dc] = true
racks[fmt.Sprintf("%s %s", targetNode.dc, targetNode.rack)]++
if len(dcs) != placement.DiffDataCenterCount+1 {
return false
}
if len(racks) != placement.DiffRackCount+placement.DiffDataCenterCount+1 {
return false
}
for _, sameRackCount := range racks {
if sameRackCount != placement.SameRackCount+1 {
return false
}
}
return true
}
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
return
}
}
}