diff options
Diffstat (limited to 'weed/shell/command_ec_balance.go')
| -rw-r--r-- | weed/shell/command_ec_balance.go | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/weed/shell/command_ec_balance.go b/weed/shell/command_ec_balance.go new file mode 100644 index 000000000..299d44fed --- /dev/null +++ b/weed/shell/command_ec_balance.go @@ -0,0 +1,515 @@ +package shell + +import ( + "flag" + "fmt" + "io" + "sort" + + "github.com/chrislusf/seaweedfs/weed/storage/erasure_coding" + "github.com/chrislusf/seaweedfs/weed/storage/needle" +) + +func init() { + Commands = append(Commands, &commandEcBalance{}) +} + +type commandEcBalance struct { +} + +func (c *commandEcBalance) Name() string { + return "ec.balance" +} + +func (c *commandEcBalance) Help() string { + return `balance all ec shards among all racks and volume servers + + ec.balance [-c EACH_COLLECTION|<collection_name>] [-force] [-dataCenter <data_center>] + + Algorithm: + + For each type of volume server (different max volume count limit){ + for each collection: + balanceEcVolumes(collectionName) + for each rack: + balanceEcRack(rack) + } + + func balanceEcVolumes(collectionName){ + for each volume: + doDeduplicateEcShards(volumeId) + + tracks rack~shardCount mapping + for each volume: + doBalanceEcShardsAcrossRacks(volumeId) + + for each volume: + doBalanceEcShardsWithinRacks(volumeId) + } + + // spread ec shards into more racks + func doBalanceEcShardsAcrossRacks(volumeId){ + tracks rack~volumeIdShardCount mapping + averageShardsPerEcRack = totalShardNumber / numRacks // totalShardNumber is 14 for now, later could varies for each dc + ecShardsToMove = select overflown ec shards from racks with ec shard counts > averageShardsPerEcRack + for each ecShardsToMove { + destRack = pickOneRack(rack~shardCount, rack~volumeIdShardCount, averageShardsPerEcRack) + destVolumeServers = volume servers on the destRack + pickOneEcNodeAndMoveOneShard(destVolumeServers) + } + } + + func doBalanceEcShardsWithinRacks(volumeId){ + racks = collect all racks that the volume id is on + for rack, shards := range racks + doBalanceEcShardsWithinOneRack(volumeId, shards, rack) + } + + // move ec shards + func doBalanceEcShardsWithinOneRack(volumeId, shards, rackId){ + tracks volumeServer~volumeIdShardCount mapping + averageShardCount = len(shards) / numVolumeServers + volumeServersOverAverage = volume servers with volumeId's ec shard counts > averageShardsPerEcRack + ecShardsToMove = select overflown ec shards from volumeServersOverAverage + for each ecShardsToMove { + destVolumeServer = pickOneVolumeServer(volumeServer~shardCount, volumeServer~volumeIdShardCount, averageShardCount) + pickOneEcNodeAndMoveOneShard(destVolumeServers) + } + } + + // move ec shards while keeping shard distribution for the same volume unchanged or more even + func balanceEcRack(rack){ + averageShardCount = total shards / numVolumeServers + for hasMovedOneEcShard { + sort all volume servers ordered by the number of local ec shards + pick the volume server A with the lowest number of ec shards x + pick the volume server B with the highest number of ec shards y + if y > averageShardCount and x +1 <= averageShardCount { + if B has a ec shard with volume id v that A does not have { + move one ec shard v from B to A + hasMovedOneEcShard = true + } + } + } + } + +` +} + +func (c *commandEcBalance) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) { + + balanceCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError) + collection := balanceCommand.String("collection", "EACH_COLLECTION", "collection name, or \"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 all ec nodes + allEcNodes, totalFreeEcSlots, err := collectEcNodes(commandEnv, *dc) + if err != nil { + return err + } + if totalFreeEcSlots < 1 { + return fmt.Errorf("no free ec shard slots. only %d left", totalFreeEcSlots) + } + + racks := collectRacks(allEcNodes) + + if *collection == "EACH_COLLECTION" { + collections, err := ListCollectionNames(commandEnv, false, true) + if err != nil { + return err + } + fmt.Printf("balanceEcVolumes collections %+v\n", len(collections)) + for _, c := range collections { + fmt.Printf("balanceEcVolumes collection %+v\n", c) + if err = balanceEcVolumes(commandEnv, c, allEcNodes, racks, *applyBalancing); err != nil { + return err + } + } + } else { + if err = balanceEcVolumes(commandEnv, *collection, allEcNodes, racks, *applyBalancing); err != nil { + return err + } + } + + if err := balanceEcRacks(commandEnv, racks, *applyBalancing); err != nil { + return fmt.Errorf("balance ec racks: %v", err) + } + + return nil +} + +func collectRacks(allEcNodes []*EcNode) map[RackId]*EcRack { + // collect racks info + racks := make(map[RackId]*EcRack) + for _, ecNode := range allEcNodes { + if racks[ecNode.rack] == nil { + racks[ecNode.rack] = &EcRack{ + ecNodes: make(map[EcNodeId]*EcNode), + } + } + racks[ecNode.rack].ecNodes[EcNodeId(ecNode.info.Id)] = ecNode + racks[ecNode.rack].freeEcSlot += ecNode.freeEcSlot + } + return racks +} + +func balanceEcVolumes(commandEnv *CommandEnv, collection string, allEcNodes []*EcNode, racks map[RackId]*EcRack, applyBalancing bool) error { + + fmt.Printf("balanceEcVolumes %s\n", collection) + + if err := deleteDuplicatedEcShards(commandEnv, allEcNodes, collection, applyBalancing); err != nil { + return fmt.Errorf("delete duplicated collection %s ec shards: %v", collection, err) + } + + if err := balanceEcShardsAcrossRacks(commandEnv, allEcNodes, racks, collection, applyBalancing); err != nil { + return fmt.Errorf("balance across racks collection %s ec shards: %v", collection, err) + } + + if err := balanceEcShardsWithinRacks(commandEnv, allEcNodes, racks, collection, applyBalancing); err != nil { + return fmt.Errorf("balance across racks collection %s ec shards: %v", collection, err) + } + + return nil +} + +func deleteDuplicatedEcShards(commandEnv *CommandEnv, allEcNodes []*EcNode, collection string, applyBalancing bool) error { + // vid => []ecNode + vidLocations := collectVolumeIdToEcNodes(allEcNodes) + // deduplicate ec shards + for vid, locations := range vidLocations { + if err := doDeduplicateEcShards(commandEnv, collection, vid, locations, applyBalancing); err != nil { + return err + } + } + return nil +} + +func doDeduplicateEcShards(commandEnv *CommandEnv, collection string, vid needle.VolumeId, locations []*EcNode, applyBalancing bool) error { + + // check whether this volume has ecNodes that are over average + shardToLocations := make([][]*EcNode, erasure_coding.TotalShardsCount) + for _, ecNode := range locations { + shardBits := findEcVolumeShards(ecNode, vid) + for _, shardId := range shardBits.ShardIds() { + shardToLocations[shardId] = append(shardToLocations[shardId], ecNode) + } + } + for shardId, ecNodes := range shardToLocations { + if len(ecNodes) <= 1 { + continue + } + sortEcNodesByFreeslotsAscending(ecNodes) + fmt.Printf("ec shard %d.%d has %d copies, keeping %v\n", vid, shardId, len(ecNodes), ecNodes[0].info.Id) + if !applyBalancing { + continue + } + + duplicatedShardIds := []uint32{uint32(shardId)} + for _, ecNode := range ecNodes[1:] { + if err := unmountEcShards(commandEnv.option.GrpcDialOption, vid, ecNode.info.Id, duplicatedShardIds); err != nil { + return err + } + if err := sourceServerDeleteEcShards(commandEnv.option.GrpcDialOption, collection, vid, ecNode.info.Id, duplicatedShardIds); err != nil { + return err + } + ecNode.deleteEcVolumeShards(vid, duplicatedShardIds) + } + } + return nil +} + +func balanceEcShardsAcrossRacks(commandEnv *CommandEnv, allEcNodes []*EcNode, racks map[RackId]*EcRack, collection string, applyBalancing bool) error { + // collect vid => []ecNode, since previous steps can change the locations + vidLocations := collectVolumeIdToEcNodes(allEcNodes) + // spread the ec shards evenly + for vid, locations := range vidLocations { + if err := doBalanceEcShardsAcrossRacks(commandEnv, collection, vid, locations, racks, applyBalancing); err != nil { + return err + } + } + return nil +} + +func doBalanceEcShardsAcrossRacks(commandEnv *CommandEnv, collection string, vid needle.VolumeId, locations []*EcNode, racks map[RackId]*EcRack, applyBalancing bool) error { + + // calculate average number of shards an ec rack should have for one volume + averageShardsPerEcRack := ceilDivide(erasure_coding.TotalShardsCount, len(racks)) + + // see the volume's shards are in how many racks, and how many in each rack + rackToShardCount := groupByCount(locations, func(ecNode *EcNode) (id string, count int) { + shardBits := findEcVolumeShards(ecNode, vid) + return string(ecNode.rack), shardBits.ShardIdCount() + }) + rackEcNodesWithVid := groupBy(locations, func(ecNode *EcNode) string { + return string(ecNode.rack) + }) + + // ecShardsToMove = select overflown ec shards from racks with ec shard counts > averageShardsPerEcRack + ecShardsToMove := make(map[erasure_coding.ShardId]*EcNode) + for rackId, count := range rackToShardCount { + if count > averageShardsPerEcRack { + possibleEcNodes := rackEcNodesWithVid[rackId] + for shardId, ecNode := range pickNEcShardsToMoveFrom(possibleEcNodes, vid, count-averageShardsPerEcRack) { + ecShardsToMove[shardId] = ecNode + } + } + } + + for shardId, ecNode := range ecShardsToMove { + rackId := pickOneRack(racks, rackToShardCount, averageShardsPerEcRack) + if rackId == "" { + fmt.Printf("ec shard %d.%d at %s can not find a destination rack\n", vid, shardId, ecNode.info.Id) + continue + } + var possibleDestinationEcNodes []*EcNode + for _, n := range racks[rackId].ecNodes { + possibleDestinationEcNodes = append(possibleDestinationEcNodes, n) + } + err := pickOneEcNodeAndMoveOneShard(commandEnv, averageShardsPerEcRack, ecNode, collection, vid, shardId, possibleDestinationEcNodes, applyBalancing) + if err != nil { + return err + } + rackToShardCount[string(rackId)] += 1 + rackToShardCount[string(ecNode.rack)] -= 1 + racks[rackId].freeEcSlot -= 1 + racks[ecNode.rack].freeEcSlot += 1 + } + + return nil +} + +func pickOneRack(rackToEcNodes map[RackId]*EcRack, rackToShardCount map[string]int, averageShardsPerEcRack int) RackId { + + // TODO later may need to add some randomness + + for rackId, rack := range rackToEcNodes { + if rackToShardCount[string(rackId)] >= averageShardsPerEcRack { + continue + } + + if rack.freeEcSlot <= 0 { + continue + } + + return rackId + } + + return "" +} + +func balanceEcShardsWithinRacks(commandEnv *CommandEnv, allEcNodes []*EcNode, racks map[RackId]*EcRack, collection string, applyBalancing bool) error { + // collect vid => []ecNode, since previous steps can change the locations + vidLocations := collectVolumeIdToEcNodes(allEcNodes) + + // spread the ec shards evenly + for vid, locations := range vidLocations { + + // see the volume's shards are in how many racks, and how many in each rack + rackToShardCount := groupByCount(locations, func(ecNode *EcNode) (id string, count int) { + shardBits := findEcVolumeShards(ecNode, vid) + return string(ecNode.rack), shardBits.ShardIdCount() + }) + rackEcNodesWithVid := groupBy(locations, func(ecNode *EcNode) string { + return string(ecNode.rack) + }) + + for rackId, _ := range rackToShardCount { + + var possibleDestinationEcNodes []*EcNode + for _, n := range racks[RackId(rackId)].ecNodes { + possibleDestinationEcNodes = append(possibleDestinationEcNodes, n) + } + sourceEcNodes := rackEcNodesWithVid[rackId] + averageShardsPerEcNode := ceilDivide(rackToShardCount[rackId], len(possibleDestinationEcNodes)) + if err := doBalanceEcShardsWithinOneRack(commandEnv, averageShardsPerEcNode, collection, vid, sourceEcNodes, possibleDestinationEcNodes, applyBalancing); err != nil { + return err + } + } + } + return nil +} + +func doBalanceEcShardsWithinOneRack(commandEnv *CommandEnv, averageShardsPerEcNode int, collection string, vid needle.VolumeId, existingLocations, possibleDestinationEcNodes []*EcNode, applyBalancing bool) error { + + for _, ecNode := range existingLocations { + + shardBits := findEcVolumeShards(ecNode, vid) + overLimitCount := shardBits.ShardIdCount() - averageShardsPerEcNode + + for _, shardId := range shardBits.ShardIds() { + + if overLimitCount <= 0 { + break + } + + fmt.Printf("%s has %d overlimit, moving ec shard %d.%d\n", ecNode.info.Id, overLimitCount, vid, shardId) + + err := pickOneEcNodeAndMoveOneShard(commandEnv, averageShardsPerEcNode, ecNode, collection, vid, shardId, possibleDestinationEcNodes, applyBalancing) + if err != nil { + return err + } + + overLimitCount-- + } + } + + return nil +} + +func balanceEcRacks(commandEnv *CommandEnv, racks map[RackId]*EcRack, applyBalancing bool) error { + + // balance one rack for all ec shards + for _, ecRack := range racks { + if err := doBalanceEcRack(commandEnv, ecRack, applyBalancing); err != nil { + return err + } + } + return nil +} + +func doBalanceEcRack(commandEnv *CommandEnv, ecRack *EcRack, applyBalancing bool) error { + + if len(ecRack.ecNodes) <= 1 { + return nil + } + + var rackEcNodes []*EcNode + for _, node := range ecRack.ecNodes { + rackEcNodes = append(rackEcNodes, node) + } + + ecNodeIdToShardCount := groupByCount(rackEcNodes, func(node *EcNode) (id string, count int) { + for _, ecShardInfo := range node.info.EcShardInfos { + count += erasure_coding.ShardBits(ecShardInfo.EcIndexBits).ShardIdCount() + } + return node.info.Id, count + }) + + var totalShardCount int + for _, count := range ecNodeIdToShardCount { + totalShardCount += count + } + + averageShardCount := ceilDivide(totalShardCount, len(rackEcNodes)) + + hasMove := true + for hasMove { + hasMove = false + sort.Slice(rackEcNodes, func(i, j int) bool { + return rackEcNodes[i].freeEcSlot > rackEcNodes[j].freeEcSlot + }) + emptyNode, fullNode := rackEcNodes[0], rackEcNodes[len(rackEcNodes)-1] + emptyNodeShardCount, fullNodeShardCount := ecNodeIdToShardCount[emptyNode.info.Id], ecNodeIdToShardCount[fullNode.info.Id] + if fullNodeShardCount > averageShardCount && emptyNodeShardCount+1 <= averageShardCount { + + emptyNodeIds := make(map[uint32]bool) + for _, shards := range emptyNode.info.EcShardInfos { + emptyNodeIds[shards.Id] = true + } + for _, shards := range fullNode.info.EcShardInfos { + if _, found := emptyNodeIds[shards.Id]; !found { + for _, shardId := range erasure_coding.ShardBits(shards.EcIndexBits).ShardIds() { + + fmt.Printf("%s moves ec shards %d.%d to %s\n", fullNode.info.Id, shards.Id, shardId, emptyNode.info.Id) + + err := moveMountedShardToEcNode(commandEnv, fullNode, shards.Collection, needle.VolumeId(shards.Id), shardId, emptyNode, applyBalancing) + if err != nil { + return err + } + + ecNodeIdToShardCount[emptyNode.info.Id]++ + ecNodeIdToShardCount[fullNode.info.Id]-- + hasMove = true + break + } + break + } + } + } + } + + return nil +} + +func pickOneEcNodeAndMoveOneShard(commandEnv *CommandEnv, averageShardsPerEcNode int, existingLocation *EcNode, collection string, vid needle.VolumeId, shardId erasure_coding.ShardId, possibleDestinationEcNodes []*EcNode, applyBalancing bool) error { + + sortEcNodesByFreeslotsDecending(possibleDestinationEcNodes) + + for _, destEcNode := range possibleDestinationEcNodes { + if destEcNode.info.Id == existingLocation.info.Id { + continue + } + + if destEcNode.freeEcSlot <= 0 { + continue + } + if findEcVolumeShards(destEcNode, vid).ShardIdCount() >= averageShardsPerEcNode { + continue + } + + fmt.Printf("%s moves ec shard %d.%d to %s\n", existingLocation.info.Id, vid, shardId, destEcNode.info.Id) + + err := moveMountedShardToEcNode(commandEnv, existingLocation, collection, vid, shardId, destEcNode, applyBalancing) + if err != nil { + return err + } + + return nil + } + + return nil +} + +func pickNEcShardsToMoveFrom(ecNodes []*EcNode, vid needle.VolumeId, n int) map[erasure_coding.ShardId]*EcNode { + picked := make(map[erasure_coding.ShardId]*EcNode) + var candidateEcNodes []*CandidateEcNode + for _, ecNode := range ecNodes { + shardBits := findEcVolumeShards(ecNode, vid) + if shardBits.ShardIdCount() > 0 { + candidateEcNodes = append(candidateEcNodes, &CandidateEcNode{ + ecNode: ecNode, + shardCount: shardBits.ShardIdCount(), + }) + } + } + sort.Slice(candidateEcNodes, func(i, j int) bool { + return candidateEcNodes[i].shardCount > candidateEcNodes[j].shardCount + }) + for i := 0; i < n; i++ { + selectedEcNodeIndex := -1 + for i, candidateEcNode := range candidateEcNodes { + shardBits := findEcVolumeShards(candidateEcNode.ecNode, vid) + if shardBits > 0 { + selectedEcNodeIndex = i + for _, shardId := range shardBits.ShardIds() { + candidateEcNode.shardCount-- + picked[shardId] = candidateEcNode.ecNode + candidateEcNode.ecNode.deleteEcVolumeShards(vid, []uint32{uint32(shardId)}) + break + } + break + } + } + if selectedEcNodeIndex >= 0 { + ensureSortedEcNodes(candidateEcNodes, selectedEcNodeIndex, func(i, j int) bool { + return candidateEcNodes[i].shardCount > candidateEcNodes[j].shardCount + }) + } + + } + return picked +} + +func collectVolumeIdToEcNodes(allEcNodes []*EcNode) map[needle.VolumeId][]*EcNode { + vidLocations := make(map[needle.VolumeId][]*EcNode) + for _, ecNode := range allEcNodes { + for _, shardInfo := range ecNode.info.EcShardInfos { + vidLocations[needle.VolumeId(shardInfo.Id)] = append(vidLocations[needle.VolumeId(shardInfo.Id)], ecNode) + } + } + return vidLocations +} |