Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

@@ -0,0 +2,4 @@
+
+import "context"
+
+type routineLimiter struct {

@@ -288,2 +287,4 @@
 	}
 
+	limiter := newRoutineLimiter(e.cfg.evacuationWorkers)
+	eg, egCtx := errgroup.WithContext(ctx)

@@ -91,0 +100,4 @@
+
+// EngineEvacuationWorkersCount returns value of "evacuation_workers_count" config parmeter from "storage" section.
+func EngineEvacuationWorkersCount(c *config.Config) uint32 {
+	if v := config.Uint32Safe(c.Sub(subsection), "evacuation_workers_count"); v > 0 {

@@ -220,2 +224,4 @@
 		log:           &logger.Logger{Logger: zap.L()},
 		shardPoolSize: 20,
+
+		evacuationWorkers:         5,

@@ -294,2 +291,2 @@
-			return err
-		}
+		eg.Go(func() error {
+			if err = e.evacuateShard(egCtx, shardID, prm, res, shards, shardsToEvacuate); err != nil {

@@ -21,6 +21,9 @@ const (
 	noProgressFlag = "no-progress"
 	scopeFlag      = "scope"
 
+	containerWorkerCountFlag = "container-worker-count"

@@ -16,2 +16,4 @@
 	// process object PUT operations in a storage engine.
 	ShardPoolSizeDefault = 20
+	// EvacuationShardWorkerCountDefault is a default value of the count of shards
+	// evacuees concurrently.

@@ -176,0 +171,4 @@
+|-------------------------------------|-----------------------------------|---------------|------------------------------------------------------------------------------------------------------------------|
+| `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. |
+| `evacuation_container_worker_count` | `int`                             | `10`          | The count of the concurrent container evacuation workers.                                                        |

@@ -287,12 +296,44 @@ func (e *StorageEngine) evacuateShards(ctx context.Context, shardIDs []string, p
 		return err
 	}
 
+	egShard, _ := errgroup.WithContext(ctx)

@@ -262,0 +317,4 @@
+			continue
+		}
+
+		bkt := tx.Bucket(name)

@@ -167,0 +187,4 @@
+		))
+	defer span.End()
+
+	if s.GetMode().NoMetabase() {

@@ -371,6 +378,8 @@ func initControlStartEvacuationShardCmd() {
 	flags.String(scopeFlag, scopeAll, fmt.Sprintf("Evacuation scope; possible values: %s, %s, %s", scopeTrees, scopeObjects, scopeAll))
 	flags.Bool(awaitFlag, false, "Block execution until evacuation is completed")
 	flags.Bool(noProgressFlag, false, fmt.Sprintf("Print progress if %s provided", awaitFlag))
+	flags.Uint32(containerWorkerCountFlag, 0, "Count of concurrent container evacuation workers")

@@ -312,0 +356,4 @@
+func (e *StorageEngine) createErrorGroupsForEvacuation(ctx context.Context, prm EvacuateShardPrm) (
+	context.Context, context.CancelCauseFunc, *errgroup.Group, *errgroup.Group, *errgroup.Group,
+) {
+	operationCtx, cancel := context.WithCancelCause(ctx)

@@ -64,0 +69,4 @@
+
+// IterateOverObjectsInContainerPrm contains parameters for IterateOverObjectsInContainer operation.
+type IterateOverObjectsInContainerPrm struct {
+	// BucketName container's bucket name

@@ -262,0 +313,4 @@
+		if cidRaw == nil {
+			continue
+		}
+		if prefix != primaryPrefix && prefix != lockersPrefix && prefix != tombstonePrefix {

@@ -262,0 +367,4 @@
+	k, v := c.First()
+
+	var containerID cid.ID
+	cidRaw, prefix := parseContainerIDWithPrefix(&containerID, prm.BucketName)

@@ -262,0 +360,4 @@
+}
+
+func (db *DB) iterateOverObjectsInContainer(ctx context.Context, tx *bbolt.Tx, prm IterateOverObjectsInContainerPrm) error {
+	bkt := tx.Bucket(prm.BucketName)