[#1667] shard: Drop shard pool

After adding an ops limiter, shard's `put` pool is redundant.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

cmd/frostfs-adm/internal/modules/storagecfg/config.go

@@ -40,8 +40,6 @@ morph:
     - address: wss://{{.}}/ws{{end}}
 {{if not .Relay }}
 storage:
-  shard_pool_size: 15  # size of per-shard worker pools used for PUT operations
-
   shard:
     default: # section with the default shard parameters
       metabase:

cmd/frostfs-node/config.go

@@ -117,7 +117,6 @@ type applicationConfiguration struct {
 
 	EngineCfg struct {
 		errorThreshold uint32
-		shardPoolSize  uint32
 		shards         []shardCfg
 		lowMem         bool
 	}
@@ -250,7 +249,6 @@ func (a *applicationConfiguration) readConfig(c *config.Config) error {
 	// Storage Engine
 
 	a.EngineCfg.errorThreshold = engineconfig.ShardErrorThreshold(c)
-	a.EngineCfg.shardPoolSize = engineconfig.ShardPoolSize(c)
 	a.EngineCfg.lowMem = engineconfig.EngineLowMemoryConsumption(c)
 
 	return engineconfig.IterateShards(c, false, func(sc *shardconfig.Config) error { return a.updateShardConfig(c, sc) })
@@ -893,7 +891,6 @@ func (c *cfg) engineOpts() []engine.Option {
 	var opts []engine.Option
 
 	opts = append(opts,
-		engine.WithShardPoolSize(c.EngineCfg.shardPoolSize),
 		engine.WithErrorThreshold(c.EngineCfg.errorThreshold),
 		engine.WithLogger(c.log),
 		engine.WithLowMemoryConsumption(c.EngineCfg.lowMem),

cmd/frostfs-node/config/configdir_test.go

@@ -12,13 +12,10 @@ import (
 func TestConfigDir(t *testing.T) {
 	dir := t.TempDir()
 
-	cfgFileName0 := path.Join(dir, "cfg_00.json")
+	cfgFileName := path.Join(dir, "cfg_01.yml")
-	cfgFileName1 := path.Join(dir, "cfg_01.yml")
 
-	require.NoError(t, os.WriteFile(cfgFileName0, []byte(`{"storage":{"shard_pool_size":15}}`), 0o777))
+	require.NoError(t, os.WriteFile(cfgFileName, []byte("logger:\n  level: debug"), 0o777))
-	require.NoError(t, os.WriteFile(cfgFileName1, []byte("logger:\n  level: debug"), 0o777))
 
 	c := New("", dir, "")
 	require.Equal(t, "debug", cast.ToString(c.Sub("logger").Value("level")))
-	require.EqualValues(t, 15, cast.ToUint32(c.Sub("storage").Value("shard_pool_size")))
 }

cmd/frostfs-node/config/engine/config.go

@@ -11,10 +11,6 @@ import (
 
 const (
 	subsection = "storage"
-
-	// ShardPoolSizeDefault is a default value of routine pool size per-shard to
-	// process object PUT operations in a storage engine.
-	ShardPoolSizeDefault = 20
 )
 
 // ErrNoShardConfigured is returned when at least 1 shard is required but none are found.
@@ -65,18 +61,6 @@ func IterateShards(c *config.Config, required bool, f func(*shardconfig.Config)
 	return nil
 }
 
-// ShardPoolSize returns the value of "shard_pool_size" config parameter from "storage" section.
-//
-// Returns ShardPoolSizeDefault if the value is not a positive number.
-func ShardPoolSize(c *config.Config) uint32 {
-	v := config.Uint32Safe(c.Sub(subsection), "shard_pool_size")
-	if v > 0 {
-		return v
-	}
-
-	return ShardPoolSizeDefault
-}
-
 // ShardErrorThreshold returns the value of "shard_ro_error_threshold" config parameter from "storage" section.
 //
 // Returns 0 if the the value is missing.

cmd/frostfs-node/config/engine/config_test.go

@@ -54,7 +54,6 @@ func TestEngineSection(t *testing.T) {
 		require.False(t, handlerCalled)
 
 		require.EqualValues(t, 0, engineconfig.ShardErrorThreshold(empty))
-		require.EqualValues(t, engineconfig.ShardPoolSizeDefault, engineconfig.ShardPoolSize(empty))
 		require.EqualValues(t, mode.ReadWrite, shardconfig.From(empty).Mode())
 	})
 
@@ -64,7 +63,6 @@ func TestEngineSection(t *testing.T) {
 		num := 0
 
 		require.EqualValues(t, 100, engineconfig.ShardErrorThreshold(c))
-		require.EqualValues(t, 15, engineconfig.ShardPoolSize(c))
 
 		err := engineconfig.IterateShards(c, true, func(sc *shardconfig.Config) error {
 			defer func() {

config/example/node.env

@@ -97,7 +97,6 @@ FROSTFS_RPC_LIMITS_1_METHODS="/neo.fs.v2.object.ObjectService/Get"
 FROSTFS_RPC_LIMITS_1_MAX_OPS=10000
 
 # Storage engine section
-FROSTFS_STORAGE_SHARD_POOL_SIZE=15
 FROSTFS_STORAGE_SHARD_RO_ERROR_THRESHOLD=100
 ## 0 shard
 ### Flag to refill Metabase from BlobStor

config/example/node.json

@@ -158,7 +158,6 @@
     ]
   },
   "storage": {
-    "shard_pool_size": 15,
     "shard_ro_error_threshold": 100,
     "shard": {
       "0": {

config/example/node.yaml

@@ -135,7 +135,6 @@ rpc:
 
 storage:
   # note: shard configuration can be omitted for relay node (see `node.relay`)
-  shard_pool_size: 15 # size of per-shard worker pools used for PUT operations
   shard_ro_error_threshold: 100 # amount of errors to occur before shard is made read-only (default: 0, ignore errors)
 
   shard:

docs/storage-node-configuration.md

@@ -170,7 +170,6 @@ Local storage engine configuration.
 
 | Parameter                  | Type                              | Default value | Description                                                                                                      |
 |----------------------------|-----------------------------------|---------------|------------------------------------------------------------------------------------------------------------------|
-| `shard_pool_size`          | `int`                             | `20`          | Pool size for shard workers. Limits the amount of concurrent `PUT` operations on each shard.                     |
 | `shard_ro_error_threshold` | `int`                             | `0`           | Maximum amount of storage errors to encounter before shard automatically moves to `Degraded` or `ReadOnly` mode. |
 | `low_mem`                  | `bool`                            | `false`       | Reduce memory consumption by reducing performance.                                                               |
 | `shard`                    | [Shard config](#shard-subsection) |               | Configuration for separate shards.                                                                               |

pkg/local_object_storage/engine/control.go

@@ -153,16 +153,10 @@ func (e *StorageEngine) Close(ctx context.Context) error {
 }
 
 // closes all shards. Never returns an error, shard errors are logged.
-func (e *StorageEngine) close(ctx context.Context, releasePools bool) error {
+func (e *StorageEngine) close(ctx context.Context) error {
 	e.mtx.RLock()
 	defer e.mtx.RUnlock()
 
-	if releasePools {
-		for _, p := range e.shardPools {
-			p.Release()
-		}
-	}
-
 	for id, sh := range e.shards {
 		if err := sh.Close(ctx); err != nil {
 			e.log.Debug(ctx, logs.EngineCouldNotCloseShard,
@@ -213,7 +207,7 @@ func (e *StorageEngine) setBlockExecErr(ctx context.Context, err error) error {
 			return e.open(ctx)
 		}
 	} else if prevErr == nil { // ok -> block
-		return e.close(ctx, errors.Is(err, errClosed))
+		return e.close(ctx)
 	}
 
 	// otherwise do nothing

pkg/local_object_storage/engine/control_test.go

@@ -245,7 +245,6 @@ func TestReload(t *testing.T) {
 
 		// no new paths => no new shards
 		require.Equal(t, shardNum, len(e.shards))
-		require.Equal(t, shardNum, len(e.shardPools))
 
 		newMeta := filepath.Join(addPath, fmt.Sprintf("%d.metabase", shardNum))
 
@@ -257,7 +256,6 @@ func TestReload(t *testing.T) {
 		require.NoError(t, e.Reload(context.Background(), rcfg))
 
 		require.Equal(t, shardNum+1, len(e.shards))
-		require.Equal(t, shardNum+1, len(e.shardPools))
 
 		require.NoError(t, e.Close(context.Background()))
 	})
@@ -277,7 +275,6 @@ func TestReload(t *testing.T) {
 
 		// removed one
 		require.Equal(t, shardNum-1, len(e.shards))
-		require.Equal(t, shardNum-1, len(e.shardPools))
 
 		require.NoError(t, e.Close(context.Background()))
 	})
@@ -311,7 +308,6 @@ func engineWithShards(t *testing.T, path string, num int) (*StorageEngine, []str
 	}
 
 	require.Equal(t, num, len(e.shards))
-	require.Equal(t, num, len(e.shardPools))
 
 	return e, currShards
 }

pkg/local_object_storage/engine/engine.go

@@ -12,7 +12,6 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard/mode"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
@@ -29,8 +28,6 @@ type StorageEngine struct {
 
 	shards map[string]hashedShard
 
-	shardPools map[string]util.WorkerPool
-
 	closeCh   chan struct{}
 	setModeCh chan setModeRequest
 	wg        sync.WaitGroup
@@ -193,8 +190,6 @@ type cfg struct {
 
 	metrics MetricRegister
 
-	shardPoolSize uint32
-
 	lowMem bool
 
 	containerSource atomic.Pointer[containerSource]
@@ -202,9 +197,8 @@ type cfg struct {
 
 func defaultCfg() *cfg {
 	res := &cfg{
-		log:           logger.NewLoggerWrapper(zap.L()),
+		log:     logger.NewLoggerWrapper(zap.L()),
-		shardPoolSize: 20,
+		metrics: noopMetrics{},
-		metrics:       noopMetrics{},
 	}
 	res.containerSource.Store(&containerSource{})
 	return res
@@ -221,7 +215,6 @@ func New(opts ...Option) *StorageEngine {
 	return &StorageEngine{
 		cfg:             c,
 		shards:          make(map[string]hashedShard),
-		shardPools:      make(map[string]util.WorkerPool),
 		closeCh:         make(chan struct{}),
 		setModeCh:       make(chan setModeRequest),
 		evacuateLimiter: &evacuationLimiter{},
@@ -241,13 +234,6 @@ func WithMetrics(v MetricRegister) Option {
 	}
 }
 
-// WithShardPoolSize returns option to specify size of worker pool for each shard.
-func WithShardPoolSize(sz uint32) Option {
-	return func(c *cfg) {
-		c.shardPoolSize = sz
-	}
-}
-
 // WithErrorThreshold returns an option to specify size amount of errors after which
 // shard is moved to read-only mode.
 func WithErrorThreshold(sz uint32) Option {

pkg/local_object_storage/engine/engine_test.go

@@ -57,7 +57,6 @@ func (te *testEngineWrapper) setShardsNumOpts(
 		te.shardIDs[i] = shard.ID()
 	}
 	require.Len(t, te.engine.shards, num)
-	require.Len(t, te.engine.shardPools, num)
 	return te
 }
 

pkg/local_object_storage/engine/error_test.go

@@ -46,7 +46,6 @@ func newEngineWithErrorThreshold(t testing.TB, dir string, errThreshold uint32)
 	var testShards [2]*testShard
 
 	te := testNewEngine(t,
-		WithShardPoolSize(1),
 		WithErrorThreshold(errThreshold),
 	).
 		setShardsNumOpts(t, 2, func(id int) []shard.Option {

pkg/local_object_storage/engine/evacuate.go

@@ -15,7 +15,6 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/pilorama"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/util/logicerr"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
 	containerSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
@@ -201,11 +200,6 @@ func (p *EvacuateShardRes) DeepCopy() *EvacuateShardRes {
 	return res
 }
 
-type pooledShard struct {
-	hashedShard
-	pool util.WorkerPool
-}
-
 var errMustHaveTwoShards = errors.New("must have at least 1 spare shard")
 
 // Evacuate moves data from one shard to the others.
@@ -252,7 +246,7 @@ func (e *StorageEngine) Evacuate(ctx context.Context, prm EvacuateShardPrm) erro
 	}
 
 	var mtx sync.RWMutex
-	copyShards := func() []pooledShard {
+	copyShards := func() []hashedShard {
 		mtx.RLock()
 		defer mtx.RUnlock()
 		t := slices.Clone(shards)
@@ -266,7 +260,7 @@ func (e *StorageEngine) Evacuate(ctx context.Context, prm EvacuateShardPrm) erro
 }
 
 func (e *StorageEngine) evacuateShards(ctx context.Context, shardIDs []string, prm EvacuateShardPrm, res *EvacuateShardRes,
-	shards func() []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	shards func() []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 ) error {
 	var err error
 	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.evacuateShards",
@@ -388,7 +382,7 @@ func (e *StorageEngine) getTotals(ctx context.Context, prm EvacuateShardPrm, sha
 }
 
 func (e *StorageEngine) evacuateShard(ctx context.Context, cancel context.CancelCauseFunc, shardID string, prm EvacuateShardPrm, res *EvacuateShardRes,
-	shards func() []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	shards func() []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 	egContainer *errgroup.Group, egObject *errgroup.Group,
 ) error {
 	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.evacuateShard",
@@ -412,7 +406,7 @@ func (e *StorageEngine) evacuateShard(ctx context.Context, cancel context.Cancel
 }
 
 func (e *StorageEngine) evacuateShardObjects(ctx context.Context, cancel context.CancelCauseFunc, shardID string, prm EvacuateShardPrm, res *EvacuateShardRes,
-	shards func() []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	shards func() []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 	egContainer *errgroup.Group, egObject *errgroup.Group,
 ) error {
 	sh := shardsToEvacuate[shardID]
@@ -485,7 +479,7 @@ func (e *StorageEngine) evacuateShardObjects(ctx context.Context, cancel context
 }
 
 func (e *StorageEngine) evacuateShardTrees(ctx context.Context, shardID string, prm EvacuateShardPrm, res *EvacuateShardRes,
-	getShards func() []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	getShards func() []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 ) error {
 	sh := shardsToEvacuate[shardID]
 	shards := getShards()
@@ -515,7 +509,7 @@ func (e *StorageEngine) evacuateShardTrees(ctx context.Context, shardID string,
 }
 
 func (e *StorageEngine) evacuateTrees(ctx context.Context, sh *shard.Shard, trees []pilorama.ContainerIDTreeID,
-	prm EvacuateShardPrm, res *EvacuateShardRes, shards []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	prm EvacuateShardPrm, res *EvacuateShardRes, shards []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 ) error {
 	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.evacuateTrees",
 		trace.WithAttributes(
@@ -583,7 +577,7 @@ func (e *StorageEngine) evacuateTreeToOtherNode(ctx context.Context, sh *shard.S
 }
 
 func (e *StorageEngine) tryEvacuateTreeLocal(ctx context.Context, sh *shard.Shard, tree pilorama.ContainerIDTreeID,
-	prm EvacuateShardPrm, shards []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	prm EvacuateShardPrm, shards []hashedShard, shardsToEvacuate map[string]*shard.Shard,
 ) (bool, string, error) {
 	target, found, err := e.findShardToEvacuateTree(ctx, tree, shards, shardsToEvacuate)
 	if err != nil {
@@ -653,15 +647,15 @@ func (e *StorageEngine) tryEvacuateTreeLocal(ctx context.Context, sh *shard.Shar
 
 // findShardToEvacuateTree returns first shard according HRW or first shard with tree exists.
 func (e *StorageEngine) findShardToEvacuateTree(ctx context.Context, tree pilorama.ContainerIDTreeID,
-	shards []pooledShard, shardsToEvacuate map[string]*shard.Shard,
+	shards []hashedShard, shardsToEvacuate map[string]*shard.Shard,
-) (pooledShard, bool, error) {
+) (hashedShard, bool, error) {
 	hrw.SortHasherSliceByValue(shards, hrw.StringHash(tree.CID.EncodeToString()))
-	var result pooledShard
+	var result hashedShard
 	var found bool
 	for _, target := range shards {
 		select {
 		case <-ctx.Done():
-			return pooledShard{}, false, ctx.Err()
+			return hashedShard{}, false, ctx.Err()
 		default:
 		}
 
@@ -689,7 +683,7 @@ func (e *StorageEngine) findShardToEvacuateTree(ctx context.Context, tree pilora
 	return result, found, nil
 }
 
-func (e *StorageEngine) getActualShards(shardIDs []string, prm EvacuateShardPrm) ([]pooledShard, error) {
+func (e *StorageEngine) getActualShards(shardIDs []string, prm EvacuateShardPrm) ([]hashedShard, error) {
 	e.mtx.RLock()
 	defer e.mtx.RUnlock()
 
@@ -719,18 +713,15 @@ func (e *StorageEngine) getActualShards(shardIDs []string, prm EvacuateShardPrm)
 	// We must have all shards, to have correct information about their
 	// indexes in a sorted slice and set appropriate marks in the metabase.
 	// Evacuated shard is skipped during put.
-	shards := make([]pooledShard, 0, len(e.shards))
+	shards := make([]hashedShard, 0, len(e.shards))
 	for id := range e.shards {
-		shards = append(shards, pooledShard{
+		shards = append(shards, e.shards[id])
-			hashedShard: e.shards[id],
-			pool:        e.shardPools[id],
-		})
 	}
 	return shards, nil
 }
 
 func (e *StorageEngine) evacuateObject(ctx context.Context, shardID string, objInfo *object.Info, prm EvacuateShardPrm, res *EvacuateShardRes,
-	getShards func() []pooledShard, shardsToEvacuate map[string]*shard.Shard, cnr containerSDK.Container,
+	getShards func() []hashedShard, shardsToEvacuate map[string]*shard.Shard, cnr containerSDK.Container,
 ) error {
 	ctx, span := tracing.StartSpanFromContext(ctx, "StorageEngine.evacuateObjects")
 	defer span.End()
@@ -800,7 +791,7 @@ func (e *StorageEngine) isNotRepOne(c *container.Container) bool {
 }
 
 func (e *StorageEngine) tryEvacuateObjectLocal(ctx context.Context, addr oid.Address, object *objectSDK.Object, sh *shard.Shard,
-	shards []pooledShard, shardsToEvacuate map[string]*shard.Shard, res *EvacuateShardRes, cnr containerSDK.Container,
+	shards []hashedShard, shardsToEvacuate map[string]*shard.Shard, res *EvacuateShardRes, cnr containerSDK.Container,
 ) (bool, error) {
 	hrw.SortHasherSliceByValue(shards, hrw.StringHash(addr.EncodeToString()))
 	for j := range shards {
@@ -813,7 +804,7 @@ func (e *StorageEngine) tryEvacuateObjectLocal(ctx context.Context, addr oid.Add
 		if _, ok := shardsToEvacuate[shards[j].ID().String()]; ok {
 			continue
 		}
-		switch e.putToShard(ctx, shards[j].hashedShard, shards[j].pool, addr, object, container.IsIndexedContainer(cnr)).status {
+		switch e.putToShard(ctx, shards[j], addr, object, container.IsIndexedContainer(cnr)).status {
 		case putToShardSuccess:
 			res.objEvacuated.Add(1)
 			e.log.Debug(ctx, logs.EngineObjectIsMovedToAnotherShard,

pkg/local_object_storage/engine/evacuate_test.go

@@ -196,7 +196,6 @@ func TestEvacuateShardObjects(t *testing.T) {
 
 	e.mtx.Lock()
 	delete(e.shards, evacuateShardID)
-	delete(e.shardPools, evacuateShardID)
 	e.mtx.Unlock()
 
 	checkHasObjects(t)

pkg/local_object_storage/engine/inhume_test.go

@@ -205,7 +205,7 @@ func BenchmarkInhumeMultipart(b *testing.B) {
 func benchmarkInhumeMultipart(b *testing.B, numShards, numObjects int) {
 	b.StopTimer()
 
-	engine := testNewEngine(b, WithShardPoolSize(uint32(numObjects))).
+	engine := testNewEngine(b).
 		setShardsNum(b, numShards).prepare(b).engine
 	defer func() { require.NoError(b, engine.Close(context.Background())) }()
 

pkg/local_object_storage/engine/put.go

@@ -9,7 +9,6 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util"
 	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
 	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
@@ -99,13 +98,13 @@ func (e *StorageEngine) put(ctx context.Context, prm PutPrm) error {
 	var shRes putToShardRes
 	e.iterateOverSortedShards(addr, func(_ int, sh hashedShard) (stop bool) {
 		e.mtx.RLock()
-		pool, ok := e.shardPools[sh.ID().String()]
+		_, ok := e.shards[sh.ID().String()]
 		e.mtx.RUnlock()
 		if !ok {
 			// Shard was concurrently removed, skip.
 			return false
 		}
-		shRes = e.putToShard(ctx, sh, pool, addr, prm.Object, prm.IsIndexedContainer)
+		shRes = e.putToShard(ctx, sh, addr, prm.Object, prm.IsIndexedContainer)
 		return shRes.status != putToShardUnknown
 	})
 	switch shRes.status {
@@ -122,70 +121,59 @@ func (e *StorageEngine) put(ctx context.Context, prm PutPrm) error {
 
 // putToShard puts object to sh.
 // Return putToShardStatus and error if it is necessary to propagate an error upper.
-func (e *StorageEngine) putToShard(ctx context.Context, sh hashedShard, pool util.WorkerPool,
+func (e *StorageEngine) putToShard(ctx context.Context, sh hashedShard,
 	addr oid.Address, obj *objectSDK.Object, isIndexedContainer bool,
 ) (res putToShardRes) {
-	exitCh := make(chan struct{})
+	var existPrm shard.ExistsPrm
+	existPrm.Address = addr
 
-	if err := pool.Submit(func() {
+	exists, err := sh.Exists(ctx, existPrm)
-		defer close(exitCh)
+	if err != nil {
-
+		if shard.IsErrObjectExpired(err) {
-		var existPrm shard.ExistsPrm
+			// object is already found but
-		existPrm.Address = addr
+			// expired => do nothing with it
-
-		exists, err := sh.Exists(ctx, existPrm)
-		if err != nil {
-			if shard.IsErrObjectExpired(err) {
-				// object is already found but
-				// expired => do nothing with it
-				res.status = putToShardExists
-			} else {
-				e.log.Warn(ctx, logs.EngineCouldNotCheckObjectExistence,
-					zap.Stringer("shard_id", sh.ID()),
-					zap.Error(err))
-			}
-
-			return // this is not ErrAlreadyRemoved error so we can go to the next shard
-		}
-
-		if exists.Exists() {
 			res.status = putToShardExists
-			return
+		} else {
+			e.log.Warn(ctx, logs.EngineCouldNotCheckObjectExistence,
+				zap.Stringer("shard_id", sh.ID()),
+				zap.Error(err))
 		}
 
-		var putPrm shard.PutPrm
+		return // this is not ErrAlreadyRemoved error so we can go to the next shard
-		putPrm.SetObject(obj)
-		putPrm.SetIndexAttributes(isIndexedContainer)
-
-		_, err = sh.Put(ctx, putPrm)
-		if err != nil {
-			if errors.Is(err, shard.ErrReadOnlyMode) || errors.Is(err, blobstor.ErrNoPlaceFound) ||
-				errors.Is(err, common.ErrReadOnly) || errors.Is(err, common.ErrNoSpace) {
-				e.log.Warn(ctx, logs.EngineCouldNotPutObjectToShard,
-					zap.Stringer("shard_id", sh.ID()),
-					zap.Error(err))
-				return
-			}
-			if client.IsErrObjectAlreadyRemoved(err) {
-				e.log.Warn(ctx, logs.EngineCouldNotPutObjectToShard,
-					zap.Stringer("shard_id", sh.ID()),
-					zap.Error(err))
-				res.status = putToShardRemoved
-				res.err = err
-				return
-			}
-
-			e.reportShardError(ctx, sh, "could not put object to shard", err, zap.Stringer("address", addr))
-			return
-		}
-
-		res.status = putToShardSuccess
-	}); err != nil {
-		e.log.Warn(ctx, logs.EngineCouldNotPutObjectToShard, zap.Error(err))
-		close(exitCh)
 	}
 
-	<-exitCh
+	if exists.Exists() {
+		res.status = putToShardExists
+		return
+	}
+
+	var putPrm shard.PutPrm
+	putPrm.SetObject(obj)
+	putPrm.SetIndexAttributes(isIndexedContainer)
+
+	_, err = sh.Put(ctx, putPrm)
+	if err != nil {
+		if errors.Is(err, shard.ErrReadOnlyMode) || errors.Is(err, blobstor.ErrNoPlaceFound) ||
+			errors.Is(err, common.ErrReadOnly) || errors.Is(err, common.ErrNoSpace) {
+			e.log.Warn(ctx, logs.EngineCouldNotPutObjectToShard,
+				zap.Stringer("shard_id", sh.ID()),
+				zap.Error(err))
+			return
+		}
+		if client.IsErrObjectAlreadyRemoved(err) {
+			e.log.Warn(ctx, logs.EngineCouldNotPutObjectToShard,
+				zap.Stringer("shard_id", sh.ID()),
+				zap.Error(err))
+			res.status = putToShardRemoved
+			res.err = err
+			return
+		}
+
+		e.reportShardError(ctx, sh, "could not put object to shard", err, zap.Stringer("address", addr))
+		return
+	}
+
+	res.status = putToShardSuccess
 
 	return
 }

pkg/local_object_storage/engine/shards.go

@@ -17,7 +17,6 @@ import (
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"git.frostfs.info/TrueCloudLab/hrw"
 	"github.com/google/uuid"
-	"github.com/panjf2000/ants/v2"
 	"go.uber.org/zap"
 	"golang.org/x/sync/errgroup"
 )
@@ -181,11 +180,6 @@ func (e *StorageEngine) addShard(sh *shard.Shard) error {
 	e.mtx.Lock()
 	defer e.mtx.Unlock()
 
-	pool, err := ants.NewPool(int(e.shardPoolSize), ants.WithNonblocking(true))
-	if err != nil {
-		return fmt.Errorf("create pool: %w", err)
-	}
-
 	strID := sh.ID().String()
 	if _, ok := e.shards[strID]; ok {
 		return fmt.Errorf("shard with id %s was already added", strID)
@@ -199,8 +193,6 @@ func (e *StorageEngine) addShard(sh *shard.Shard) error {
 		hash: hrw.StringHash(strID),
 	}
 
-	e.shardPools[strID] = pool
-
 	return nil
 }
 
@@ -225,12 +217,6 @@ func (e *StorageEngine) removeShards(ctx context.Context, ids ...string) {
 		ss = append(ss, sh)
 		delete(e.shards, id)
 
-		pool, ok := e.shardPools[id]
-		if ok {
-			pool.Release()
-			delete(e.shardPools, id)
-		}
-
 		e.log.Info(ctx, logs.EngineShardHasBeenRemoved,
 			zap.String("id", id))
 	}
@@ -429,12 +415,6 @@ func (e *StorageEngine) deleteShards(ctx context.Context, ids []*shard.ID) ([]ha
 
 		delete(e.shards, idStr)
 
-		pool, ok := e.shardPools[idStr]
-		if ok {
-			pool.Release()
-			delete(e.shardPools, idStr)
-		}
-
 		e.log.Info(ctx, logs.EngineShardHasBeenRemoved,
 			zap.String("id", idStr))
 	}

pkg/local_object_storage/engine/shards_test.go

@@ -17,7 +17,6 @@ func TestRemoveShard(t *testing.T) {
 	e, ids := te.engine, te.shardIDs
 	defer func() { require.NoError(t, e.Close(context.Background())) }()
 
-	require.Equal(t, numOfShards, len(e.shardPools))
 	require.Equal(t, numOfShards, len(e.shards))
 
 	removedNum := numOfShards / 2
@@ -37,7 +36,6 @@ func TestRemoveShard(t *testing.T) {
 		}
 	}
 
-	require.Equal(t, numOfShards-removedNum, len(e.shardPools))
 	require.Equal(t, numOfShards-removedNum, len(e.shards))
 
 	for id, removed := range mSh {