Begin implementing EC balancing parallelization support. (#6342)

* Begin implementing EC balancing parallelization support.

Impacts both `ec.encode` and `ec.balance`,

* Nit: improve type naming.

* Make the goroutine workgroup handler for `EcBalance()` a bit smarter/error-proof.

* Nit: unify naming for `ecBalancer` wait group methods with the rest of the module.

* Fix concurrency bug.

* Fix whitespace after Gitlab automerge.

* Delete stray TODO.
This commit is contained in:
Lisandro Pin 2024-12-12 18:14:44 +01:00 committed by GitHub
parent 23ffbb083c
commit b0210df081
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3 changed files with 58 additions and 12 deletions

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@ -17,7 +17,6 @@ func (c *commandEcBalance) Name() string {
return "ec.balance"
}
// TODO: Update help string and move to command_ec_common.go once shard replica placement logic is enabled.
func (c *commandEcBalance) Help() string {
return `balance all ec shards among all racks and volume servers
@ -36,6 +35,7 @@ func (c *commandEcBalance) Do(args []string, commandEnv *CommandEnv, writer io.W
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")
shardReplicaPlacement := balanceCommand.String("shardReplicaPlacement", "", "replica placement for EC shards, or master default if empty")
parallelize := balanceCommand.Bool("parallelize", true, "parallelize operations whenever possible")
applyBalancing := balanceCommand.Bool("force", false, "apply the balancing plan")
if err = balanceCommand.Parse(args); err != nil {
return nil
@ -62,5 +62,5 @@ func (c *commandEcBalance) Do(args []string, commandEnv *CommandEnv, writer io.W
return err
}
return EcBalance(commandEnv, collections, *dc, rp, *applyBalancing)
return EcBalance(commandEnv, collections, *dc, rp, *parallelize, *applyBalancing)
}

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@ -6,6 +6,7 @@ import (
"fmt"
"math/rand/v2"
"sort"
"sync"
"time"
"github.com/seaweedfs/seaweedfs/weed/glog"
@ -556,6 +557,48 @@ type ecBalancer struct {
ecNodes []*EcNode
replicaPlacement *super_block.ReplicaPlacement
applyBalancing bool
parallelize bool
wg *sync.WaitGroup
// TODO: Maybe accumulate all errors instead of just the last one.
wgError error
}
type ecBalancerTask func() error
func (ecb *ecBalancer) wgInit() {
if ecb.wg == nil {
ecb.wg = &sync.WaitGroup{}
ecb.wgError = nil
}
}
func (ecb *ecBalancer) wgAdd(f ecBalancerTask) {
if ecb.wg == nil || !ecb.parallelize {
if err := f(); err != nil {
ecb.wgError = err
}
return
}
ecb.wg.Add(1)
go func() {
if err := f(); err != nil {
ecb.wgError = err
}
ecb.wg.Done()
}()
}
func (ecb *ecBalancer) wgWait() error {
if ecb.wg != nil {
ecb.wg.Wait()
}
err := ecb.wgError
ecb.wg = nil
ecb.wgError = nil
return err
}
func (ecb *ecBalancer) racks() map[RackId]*EcRack {
@ -592,15 +635,15 @@ func (ecb *ecBalancer) balanceEcVolumes(collection string) error {
}
func (ecb *ecBalancer) deleteDuplicatedEcShards(collection string) error {
// vid => []ecNode
vidLocations := ecb.collectVolumeIdToEcNodes(collection)
// deduplicate ec shards
ecb.wgInit()
for vid, locations := range vidLocations {
if err := ecb.doDeduplicateEcShards(collection, vid, locations); err != nil {
return err
}
ecb.wgAdd(func() error {
return ecb.doDeduplicateEcShards(collection, vid, locations)
})
}
return nil
return ecb.wgWait()
}
func (ecb *ecBalancer) doDeduplicateEcShards(collection string, vid needle.VolumeId, locations []*EcNode) error {
@ -636,6 +679,7 @@ func (ecb *ecBalancer) doDeduplicateEcShards(collection string, vid needle.Volum
return nil
}
// TODO: enable parallelization
func (ecb *ecBalancer) balanceEcShardsAcrossRacks(collection string) error {
// collect vid => []ecNode, since previous steps can change the locations
vidLocations := ecb.collectVolumeIdToEcNodes(collection)
@ -741,6 +785,7 @@ func (ecb *ecBalancer) pickRackToBalanceShardsInto(rackToEcNodes map[RackId]*EcR
return targets[rand.IntN(len(targets))], nil
}
// TODO: enable parallelization
func (ecb *ecBalancer) balanceEcShardsWithinRacks(collection string) error {
// collect vid => []ecNode, since previous steps can change the locations
vidLocations := ecb.collectVolumeIdToEcNodes(collection)
@ -809,6 +854,7 @@ func (ecb *ecBalancer) balanceEcRacks() error {
return nil
}
// TODO: enable parallelization
func (ecb *ecBalancer) doBalanceEcRack(ecRack *EcRack) error {
if len(ecRack.ecNodes) <= 1 {
return nil
@ -1001,7 +1047,7 @@ func (ecb *ecBalancer) collectVolumeIdToEcNodes(collection string) map[needle.Vo
return vidLocations
}
func EcBalance(commandEnv *CommandEnv, collections []string, dc string, ecReplicaPlacement *super_block.ReplicaPlacement, applyBalancing bool) (err error) {
func EcBalance(commandEnv *CommandEnv, collections []string, dc string, ecReplicaPlacement *super_block.ReplicaPlacement, parallelize bool, applyBalancing bool) (err error) {
if len(collections) == 0 {
return fmt.Errorf("no collections to balance")
}
@ -1020,6 +1066,7 @@ func EcBalance(commandEnv *CommandEnv, collections []string, dc string, ecReplic
ecNodes: allEcNodes,
replicaPlacement: ecReplicaPlacement,
applyBalancing: applyBalancing,
parallelize: parallelize,
}
for _, c := range collections {

View File

@ -65,8 +65,7 @@ func (c *commandEcEncode) Do(args []string, commandEnv *CommandEnv, writer io.Wr
collection := encodeCommand.String("collection", "", "the collection name")
fullPercentage := encodeCommand.Float64("fullPercent", 95, "the volume reaches the percentage of max volume size")
quietPeriod := encodeCommand.Duration("quietFor", time.Hour, "select volumes without no writes for this period")
// TODO: Add concurrency support to EcBalance and reenable this switch?
//parallelCopy := encodeCommand.Bool("parallelCopy", true, "copy shards in parallel")
parallelize := encodeCommand.Bool("parallelize", true, "parallelize operations whenever possible")
forceChanges := encodeCommand.Bool("force", false, "force the encoding even if the cluster has less than recommended 4 nodes")
shardReplicaPlacement := encodeCommand.String("shardReplicaPlacement", "", "replica placement for EC shards, or master default if empty")
applyBalancing := encodeCommand.Bool("rebalance", false, "re-balance EC shards after creation")
@ -125,7 +124,7 @@ func (c *commandEcEncode) Do(args []string, commandEnv *CommandEnv, writer io.Wr
}
}
// ...then re-balance ec shards.
if err := EcBalance(commandEnv, collections, "", rp, *applyBalancing); err != nil {
if err := EcBalance(commandEnv, collections, "", rp, *parallelize, *applyBalancing); err != nil {
return fmt.Errorf("re-balance ec shards for collection(s) %v: %v", collections, err)
}