[#412] Store creation epoch in tree service

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

api/data/info.go

@@ -82,6 +82,15 @@ type (
 		VersionID             string
 		NoErrorOnDeleteMarker bool
 	}
+
+	// CreatedObjectInfo stores created object info.
+	CreatedObjectInfo struct {
+		ID            oid.ID
+		Size          uint64
+		HashSum       []byte
+		MD5Sum        []byte
+		CreationEpoch uint64
+	}
 )
 
 // SettingsObjectName is a system name for a bucket settings file.

api/data/tree.go

@@ -72,6 +72,7 @@ type BaseNodeVersion struct {
 	Created        *time.Time
 	Owner          *user.ID
 	IsDeleteMarker bool
+	CreationEpoch  uint64
 }
 
 func (v *BaseNodeVersion) GetETag(md5Enabled bool) string {
@@ -110,6 +111,7 @@ type MultipartInfo struct {
 	Meta          map[string]string
 	CopiesNumbers []uint32
 	Finished      bool
+	CreationEpoch uint64
 }
 
 // PartInfo is upload information about part.

api/layer/cors.go

@@ -55,12 +55,12 @@ func (n *Layer) PutBucketCORS(ctx context.Context, p *PutCORSParams) error {
 
 	prm.Container = corsBkt.CID
 
-	_, objID, _, _, err := n.objectPutAndHash(ctx, prm, corsBkt)
+	createdObj, err := n.objectPutAndHash(ctx, prm, corsBkt)
 	if err != nil {
 		return fmt.Errorf("put cors object: %w", err)
 	}
 
-	objsToDelete, err := n.treeService.PutBucketCORS(ctx, p.BktInfo, newAddress(corsBkt.CID, objID))
+	objsToDelete, err := n.treeService.PutBucketCORS(ctx, p.BktInfo, newAddress(corsBkt.CID, createdObj.ID))
 	objToDeleteNotFound := errorsStd.Is(err, ErrNoNodeToRemove)
 	if err != nil && !objToDeleteNotFound {
 		return err

api/layer/frostfs.go

@@ -166,6 +166,12 @@ type PrmObjectCreate struct {
 	BufferMaxSize uint64
 }
 
+// CreateObjectResult is a result parameter of FrostFS.CreateObject operation.
+type CreateObjectResult struct {
+	ObjectID      oid.ID
+	CreationEpoch uint64
+}
+
 // PrmObjectDelete groups parameters of FrostFS.DeleteObject operation.
 type PrmObjectDelete struct {
 	// Authentication parameters.
@@ -261,15 +267,15 @@ type FrostFS interface {
 
 	// CreateObject creates and saves a parameterized object in the FrostFS container.
 	// It sets 'Timestamp' attribute to the current time.
-	// It returns the ID of the saved object.
+	// It returns the ID and creation epoch of the saved object.
 	//
 	// Creation time should be written into the object (UTC).
 	//
 	// It returns ErrAccessDenied on write access violation.
 	//
-	// It returns exactly one non-zero value. It returns any error encountered which
+	// It returns exactly one non-nil value. It returns any error encountered which
-	// prevented the container from being created.
+	// prevented the object from being created.
-	CreateObject(context.Context, PrmObjectCreate) (oid.ID, error)
+	CreateObject(context.Context, PrmObjectCreate) (*CreateObjectResult, error)
 
 	// DeleteObject marks the object to be removed from the FrostFS container by identifier.
 	// Successful return does not guarantee actual removal.
@@ -295,4 +301,7 @@ type FrostFS interface {
 	//
 	// It returns any error encountered which prevented computing epochs.
 	TimeToEpoch(ctx context.Context, now time.Time, future time.Time) (uint64, uint64, error)
+
+	// NetworkInfo returns parameters of FrostFS network.
+	NetworkInfo(context.Context) (netmap.NetworkInfo, error)
 }

api/layer/frostfs_mock.go

@@ -18,6 +18,7 @@ import (
 	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/session"
@@ -255,10 +256,10 @@ func (t *TestFrostFS) RangeObject(ctx context.Context, prm PrmObjectRange) (io.R
 	return io.NopCloser(bytes.NewReader(payload)), nil
 }
 
-func (t *TestFrostFS) CreateObject(_ context.Context, prm PrmObjectCreate) (oid.ID, error) {
+func (t *TestFrostFS) CreateObject(_ context.Context, prm PrmObjectCreate) (*CreateObjectResult, error) {
 	b := make([]byte, 32)
 	if _, err := io.ReadFull(rand.Reader, b); err != nil {
-		return oid.ID{}, err
+		return nil, err
 	}
 	var id oid.ID
 	id.SetSHA256(sha256.Sum256(b))
@@ -266,7 +267,7 @@ func (t *TestFrostFS) CreateObject(_ context.Context, prm PrmObjectCreate) (oid.
 	attrs := make([]object.Attribute, 0)
 
 	if err := t.objectPutErrors[prm.Filepath]; err != nil {
-		return oid.ID{}, err
+		return nil, err
 	}
 
 	if prm.Filepath != "" {
@@ -311,7 +312,7 @@ func (t *TestFrostFS) CreateObject(_ context.Context, prm PrmObjectCreate) (oid.
 	if prm.Payload != nil {
 		all, err := io.ReadAll(prm.Payload)
 		if err != nil {
-			return oid.ID{}, err
+			return nil, err
 		}
 		obj.SetPayload(all)
 		obj.SetPayloadSize(uint64(len(all)))
@@ -325,7 +326,10 @@ func (t *TestFrostFS) CreateObject(_ context.Context, prm PrmObjectCreate) (oid.
 
 	addr := newAddress(cnrID, objID)
 	t.objects[addr.EncodeToString()] = obj
-	return objID, nil
+	return &CreateObjectResult{
+		ObjectID:      objID,
+		CreationEpoch: t.currentEpoch - 1,
+	}, nil
 }
 
 func (t *TestFrostFS) DeleteObject(ctx context.Context, prm PrmObjectDelete) error {
@@ -404,6 +408,13 @@ func (t *TestFrostFS) SearchObjects(_ context.Context, prm PrmObjectSearch) ([]o
 	return res, nil
 }
 
+func (t *TestFrostFS) NetworkInfo(context.Context) (netmap.NetworkInfo, error) {
+	ni := netmap.NetworkInfo{}
+	ni.SetCurrentEpoch(t.currentEpoch)
+
+	return ni, nil
+}
+
 func (t *TestFrostFS) checkAccess(cnrID cid.ID, owner user.ID) bool {
 	cnr, ok := t.containers[cnrID.EncodeToString()]
 	if !ok {

api/layer/lifecycle.go

@@ -42,7 +42,7 @@ func (n *Layer) PutBucketLifecycleConfiguration(ctx context.Context, p *PutBucke
 
 	prm.Container = lifecycleBkt.CID
 
-	_, objID, _, md5, err := n.objectPutAndHash(ctx, prm, lifecycleBkt)
+	createdObj, err := n.objectPutAndHash(ctx, prm, lifecycleBkt)
 	if err != nil {
 		return fmt.Errorf("put lifecycle object: %w", err)
 	}
@@ -52,13 +52,13 @@ func (n *Layer) PutBucketLifecycleConfiguration(ctx context.Context, p *PutBucke
 		return apiErr.GetAPIError(apiErr.ErrInvalidDigest)
 	}
 
-	if !bytes.Equal(hashBytes, md5) {
+	if !bytes.Equal(hashBytes, createdObj.MD5Sum) {
-		n.deleteLifecycleObject(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, objID))
+		n.deleteLifecycleObject(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, createdObj.ID))
 
 		return apiErr.GetAPIError(apiErr.ErrInvalidDigest)
 	}
 
-	objsToDelete, err := n.treeService.PutBucketLifecycleConfiguration(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, objID))
+	objsToDelete, err := n.treeService.PutBucketLifecycleConfiguration(ctx, p.BktInfo, newAddress(lifecycleBkt.CID, createdObj.ID))
 	objsToDeleteNotFound := errors.Is(err, ErrNoNodeToRemove)
 	if err != nil && !objsToDeleteNotFound {
 		return err

api/layer/multipart_upload.go

@@ -150,6 +150,11 @@ func (n *Layer) CreateMultipartUpload(ctx context.Context, p *CreateMultipartPar
 		metaSize += len(p.Data.TagSet)
 	}
 
+	networkInfo, err := n.frostFS.NetworkInfo(ctx)
+	if err != nil {
+		return fmt.Errorf("get network info: %w", err)
+	}
+
 	info := &data.MultipartInfo{
 		Key:           p.Info.Key,
 		UploadID:      p.Info.UploadID,
@@ -157,6 +162,7 @@ func (n *Layer) CreateMultipartUpload(ctx context.Context, p *CreateMultipartPar
 		Created:       TimeNow(ctx),
 		Meta:          make(map[string]string, metaSize),
 		CopiesNumbers: p.CopiesNumbers,
+		CreationEpoch: networkInfo.CurrentEpoch(),
 	}
 
 	for key, val := range p.Header {
@@ -229,7 +235,7 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	prm.Attributes[0][0], prm.Attributes[0][1] = UploadIDAttributeName, p.Info.UploadID
 	prm.Attributes[1][0], prm.Attributes[1][1] = UploadPartNumberAttributeName, strconv.Itoa(p.PartNumber)
 
-	size, id, hash, md5Hash, err := n.objectPutAndHash(ctx, prm, bktInfo)
+	createdObj, err := n.objectPutAndHash(ctx, prm, bktInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -238,21 +244,21 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 		if err != nil {
 			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
 		}
-		if hex.EncodeToString(hashBytes) != hex.EncodeToString(md5Hash) {
+		if hex.EncodeToString(hashBytes) != hex.EncodeToString(createdObj.MD5Sum) {
 			prm := PrmObjectDelete{
-				Object:    id,
+				Object:    createdObj.ID,
 				Container: bktInfo.CID,
 			}
 			n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
 			err = n.frostFS.DeleteObject(ctx, prm)
 			if err != nil {
-				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", id))
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
 			return nil, s3errors.GetAPIError(s3errors.ErrInvalidDigest)
 		}
 	}
 	if p.Info.Encryption.Enabled() {
-		size = decSize
+		createdObj.Size = decSize
 	}
 
 	if !p.Info.Encryption.Enabled() && len(p.ContentSHA256Hash) > 0 && !auth.IsStandardContentSHA256(p.ContentSHA256Hash) {
@@ -260,10 +266,10 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 		if err != nil {
 			return nil, s3errors.GetAPIError(s3errors.ErrContentSHA256Mismatch)
 		}
-		if !bytes.Equal(contentHashBytes, hash) {
+		if !bytes.Equal(contentHashBytes, createdObj.HashSum) {
-			err = n.objectDelete(ctx, bktInfo, id)
+			err = n.objectDelete(ctx, bktInfo, createdObj.ID)
 			if err != nil {
-				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", id))
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
 			return nil, s3errors.GetAPIError(s3errors.ErrContentSHA256Mismatch)
 		}
@@ -271,17 +277,17 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 
 	n.reqLogger(ctx).Debug(logs.UploadPart,
 		zap.String("multipart upload", p.Info.UploadID), zap.Int("part number", p.PartNumber),
-		zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", id))
+		zap.Stringer("cid", bktInfo.CID), zap.Stringer("oid", createdObj.ID))
 
 	partInfo := &data.PartInfo{
 		Key:      p.Info.Key,
 		UploadID: p.Info.UploadID,
 		Number:   p.PartNumber,
-		OID:      id,
+		OID:      createdObj.ID,
-		Size:     size,
+		Size:     createdObj.Size,
-		ETag:     hex.EncodeToString(hash),
+		ETag:     hex.EncodeToString(createdObj.HashSum),
 		Created:  prm.CreationTime,
-		MD5:      hex.EncodeToString(md5Hash),
+		MD5:      hex.EncodeToString(createdObj.MD5Sum),
 	}
 
 	oldPartID, err := n.treeService.AddPart(ctx, bktInfo, multipartInfo.ID, partInfo)
@@ -298,7 +304,7 @@ func (n *Layer) uploadPart(ctx context.Context, multipartInfo *data.MultipartInf
 	}
 
 	objInfo := &data.ObjectInfo{
-		ID:  id,
+		ID:  createdObj.ID,
 		CID: bktInfo.CID,
 
 		Owner:   bktInfo.Owner,

api/layer/object.go

@@ -271,7 +271,7 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		prm.Attributes = append(prm.Attributes, [2]string{k, v})
 	}
 
-	size, id, hash, md5Hash, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
+	createdObj, err := n.objectPutAndHash(ctx, prm, p.BktInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -280,10 +280,10 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		if err != nil {
 			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
 		}
-		if !bytes.Equal(headerMd5Hash, md5Hash) {
+		if !bytes.Equal(headerMd5Hash, createdObj.MD5Sum) {
-			err = n.objectDelete(ctx, p.BktInfo, id)
+			err = n.objectDelete(ctx, p.BktInfo, createdObj.ID)
 			if err != nil {
-				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", id))
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
 			return nil, apiErrors.GetAPIError(apiErrors.ErrInvalidDigest)
 		}
@@ -294,25 +294,26 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 		if err != nil {
 			return nil, apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch)
 		}
-		if !bytes.Equal(contentHashBytes, hash) {
+		if !bytes.Equal(contentHashBytes, createdObj.HashSum) {
-			err = n.objectDelete(ctx, p.BktInfo, id)
+			err = n.objectDelete(ctx, p.BktInfo, createdObj.ID)
 			if err != nil {
-				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", id))
+				n.reqLogger(ctx).Debug(logs.FailedToDeleteObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", createdObj.ID))
 			}
 			return nil, apiErrors.GetAPIError(apiErrors.ErrContentSHA256Mismatch)
 		}
 	}
 
-	n.reqLogger(ctx).Debug(logs.PutObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", id))
+	n.reqLogger(ctx).Debug(logs.PutObject, zap.Stringer("cid", p.BktInfo.CID), zap.Stringer("oid", createdObj.ID))
 	now := TimeNow(ctx)
 	newVersion := &data.NodeVersion{
 		BaseNodeVersion: data.BaseNodeVersion{
-			OID:      id,
+			OID:           createdObj.ID,
-			ETag:     hex.EncodeToString(hash),
+			ETag:          hex.EncodeToString(createdObj.HashSum),
-			FilePath: p.Object,
+			FilePath:      p.Object,
-			Size:     p.Size,
+			Size:          p.Size,
-			Created:  &now,
+			Created:       &now,
-			Owner:    &n.gateOwner,
+			Owner:         &n.gateOwner,
+			CreationEpoch: createdObj.CreationEpoch,
 		},
 		IsUnversioned: !bktSettings.VersioningEnabled(),
 		IsCombined:    p.Header[MultipartObjectSize] != "",
@@ -320,7 +321,7 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 	if len(p.CompleteMD5Hash) > 0 {
 		newVersion.MD5 = p.CompleteMD5Hash
 	} else {
-		newVersion.MD5 = hex.EncodeToString(md5Hash)
+		newVersion.MD5 = hex.EncodeToString(createdObj.MD5Sum)
 	}
 
 	if newVersion.ID, err = n.treeService.AddVersion(ctx, p.BktInfo, newVersion); err != nil {
@@ -332,7 +333,7 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 			ObjVersion: &data.ObjectVersion{
 				BktInfo:    p.BktInfo,
 				ObjectName: p.Object,
-				VersionID:  id.EncodeToString(),
+				VersionID:  createdObj.ID.EncodeToString(),
 			},
 			NewLock:       p.Lock,
 			CopiesNumbers: p.CopiesNumbers,
@@ -347,13 +348,13 @@ func (n *Layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Extend
 	n.cache.CleanListCacheEntriesContainingObject(p.Object, p.BktInfo.CID)
 
 	objInfo := &data.ObjectInfo{
-		ID:  id,
+		ID:  createdObj.ID,
 		CID: p.BktInfo.CID,
 
 		Owner:       n.gateOwner,
 		Bucket:      p.BktInfo.Name,
 		Name:        p.Object,
-		Size:        size,
+		Size:        createdObj.Size,
 		Created:     prm.CreationTime,
 		Headers:     p.Header,
 		ContentType: p.Header[api.ContentType],
@@ -491,8 +492,7 @@ func (n *Layer) objectDeleteBase(ctx context.Context, bktInfo *data.BucketInfo,
 }
 
 // objectPutAndHash prepare auth parameters and invoke frostfs.CreateObject.
-// Returns object ID and payload sha256 hash.
+func (n *Layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktInfo *data.BucketInfo) (*data.CreatedObjectInfo, error) {
-func (n *Layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktInfo *data.BucketInfo) (uint64, oid.ID, []byte, []byte, error) {
 	n.prepareAuthParameters(ctx, &prm.PrmAuth, bktInfo.Owner)
 	prm.ClientCut = n.features.ClientCut()
 	prm.BufferMaxSize = n.features.BufferMaxSizeForPut()
@@ -505,15 +505,21 @@ func (n *Layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktIn
 		hash.Write(buf)
 		md5Hash.Write(buf)
 	})
-	id, err := n.frostFS.CreateObject(ctx, prm)
+	res, err := n.frostFS.CreateObject(ctx, prm)
 	if err != nil {
 		if _, errDiscard := io.Copy(io.Discard, prm.Payload); errDiscard != nil {
 			n.reqLogger(ctx).Warn(logs.FailedToDiscardPutPayloadProbablyGoroutineLeaks, zap.Error(errDiscard))
 		}
 
-		return 0, oid.ID{}, nil, nil, err
+		return nil, err
 	}
-	return size, id, hash.Sum(nil), md5Hash.Sum(nil), nil
+	return &data.CreatedObjectInfo{
+		ID:            res.ObjectID,
+		Size:          size,
+		HashSum:       hash.Sum(nil),
+		MD5Sum:        md5Hash.Sum(nil),
+		CreationEpoch: res.CreationEpoch,
+	}, nil
 }
 
 type logWrapper struct {

api/layer/object_test.go

@@ -44,7 +44,7 @@ func TestGoroutinesDontLeakInPutAndHash(t *testing.T) {
 
 	expErr := errors.New("some error")
 	tc.testFrostFS.SetObjectPutError(tc.obj, expErr)
-	_, _, _, _, err = tc.layer.objectPutAndHash(tc.ctx, prm, tc.bktInfo)
+	_, err = tc.layer.objectPutAndHash(tc.ctx, prm, tc.bktInfo)
 	require.ErrorIs(t, err, expErr)
 	require.Empty(t, payload.Len(), "body must be read out otherwise goroutines can leak in wrapReader")
 }

api/layer/system_object.go

@@ -126,8 +126,12 @@ func (n *Layer) putLockObject(ctx context.Context, bktInfo *data.BucketInfo, obj
 		return oid.ID{}, err
 	}
 
-	_, id, _, _, err := n.objectPutAndHash(ctx, prm, bktInfo)
+	createdObj, err := n.objectPutAndHash(ctx, prm, bktInfo)
-	return id, err
+	if err != nil {
+		return oid.ID{}, err
+	}
+
+	return createdObj.ID, nil
 }
 
 func (n *Layer) GetLockInfo(ctx context.Context, objVersion *data.ObjectVersion) (*data.LockInfo, error) {

internal/frostfs/authmate.go

@@ -137,12 +137,17 @@ func (x *AuthmateFrostFS) CreateObject(ctx context.Context, prm tokens.PrmObject
 		attributes = append(attributes, [2]string{attr.Key(), attr.Value()})
 	}
 
-	return x.frostFS.CreateObject(ctx, layer.PrmObjectCreate{
+	res, err := x.frostFS.CreateObject(ctx, layer.PrmObjectCreate{
 		Container:  prm.Container,
 		Filepath:   prm.Filepath,
 		Attributes: attributes,
 		Payload:    bytes.NewReader(prm.Payload),
 	})
+	if err != nil {
+		return oid.ID{}, err
+	}
+
+	return res.ObjectID, nil
 }
 
 func (x *AuthmateFrostFS) getCredVersions(ctx context.Context, addr oid.Address) (*crdt.ObjectVersions, error) {

internal/frostfs/frostfs.go

@@ -15,6 +15,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool"
@@ -51,7 +52,7 @@ func NewFrostFS(p *pool.Pool, key *keys.PrivateKey) *FrostFS {
 	}
 }
 
-// TimeToEpoch implements frostfs.FrostFS interface method.
+// TimeToEpoch implements layer.FrostFS interface method.
 func (x *FrostFS) TimeToEpoch(ctx context.Context, now, futureTime time.Time) (uint64, uint64, error) {
 	dur := futureTime.Sub(now)
 	if dur < 0 {
@@ -87,7 +88,7 @@ func (x *FrostFS) TimeToEpoch(ctx context.Context, now, futureTime time.Time) (u
 	return curr, epoch, nil
 }
 
-// Container implements frostfs.FrostFS interface method.
+// Container implements layer.FrostFS interface method.
 func (x *FrostFS) Container(ctx context.Context, layerPrm layer.PrmContainer) (*container.Container, error) {
 	prm := pool.PrmContainerGet{
 		ContainerID: layerPrm.ContainerID,
@@ -102,7 +103,7 @@ func (x *FrostFS) Container(ctx context.Context, layerPrm layer.PrmContainer) (*
 	return &res, nil
 }
 
-// CreateContainer implements frostfs.FrostFS interface method.
+// CreateContainer implements layer.FrostFS interface method.
 func (x *FrostFS) CreateContainer(ctx context.Context, prm layer.PrmContainerCreate) (*layer.ContainerCreateResult, error) {
 	var cnr container.Container
 	cnr.Init()
@@ -150,7 +151,7 @@ func (x *FrostFS) CreateContainer(ctx context.Context, prm layer.PrmContainerCre
 	}, handleObjectError("save container via connection pool", err)
 }
 
-// UserContainers implements frostfs.FrostFS interface method.
+// UserContainers implements layer.FrostFS interface method.
 func (x *FrostFS) UserContainers(ctx context.Context, layerPrm layer.PrmUserContainers) ([]cid.ID, error) {
 	prm := pool.PrmContainerList{
 		OwnerID: layerPrm.UserID,
@@ -161,7 +162,7 @@ func (x *FrostFS) UserContainers(ctx context.Context, layerPrm layer.PrmUserCont
 	return r, handleObjectError("list user containers via connection pool", err)
 }
 
-// DeleteContainer implements frostfs.FrostFS interface method.
+// DeleteContainer implements layer.FrostFS interface method.
 func (x *FrostFS) DeleteContainer(ctx context.Context, id cid.ID, token *session.Container) error {
 	prm := pool.PrmContainerDelete{ContainerID: id, Session: token, WaitParams: &x.await}
 
@@ -169,8 +170,8 @@ func (x *FrostFS) DeleteContainer(ctx context.Context, id cid.ID, token *session
 	return handleObjectError("delete container via connection pool", err)
 }
 
-// CreateObject implements frostfs.FrostFS interface method.
+// CreateObject implements layer.FrostFS interface method.
-func (x *FrostFS) CreateObject(ctx context.Context, prm layer.PrmObjectCreate) (oid.ID, error) {
+func (x *FrostFS) CreateObject(ctx context.Context, prm layer.PrmObjectCreate) (*layer.CreateObjectResult, error) {
 	attrNum := len(prm.Attributes) + 1 // + creation time
 
 	if prm.Filepath != "" {
@@ -239,10 +240,13 @@ func (x *FrostFS) CreateObject(ctx context.Context, prm layer.PrmObjectCreate) (
 
 	res, err := x.pool.PutObject(ctx, prmPut)
 	if err = handleObjectError("save object via connection pool", err); err != nil {
-		return oid.ID{}, err
+		return nil, err
 	}
 
-	return res.ObjectID, nil
+	return &layer.CreateObjectResult{
+		ObjectID:      res.ObjectID,
+		CreationEpoch: res.Epoch,
+	}, nil
 }
 
 // wraps io.ReadCloser and transforms Read errors related to access violation
@@ -259,7 +263,7 @@ func (x payloadReader) Read(p []byte) (int, error) {
 	return n, handleObjectError("read payload", err)
 }
 
-// HeadObject implements frostfs.FrostFS interface method.
+// HeadObject implements layer.FrostFS interface method.
 func (x *FrostFS) HeadObject(ctx context.Context, prm layer.PrmObjectHead) (*object.Object, error) {
 	var addr oid.Address
 	addr.SetContainer(prm.Container)
@@ -282,7 +286,7 @@ func (x *FrostFS) HeadObject(ctx context.Context, prm layer.PrmObjectHead) (*obj
 	return &res, nil
 }
 
-// GetObject implements frostfs.FrostFS interface method.
+// GetObject implements layer.FrostFS interface method.
 func (x *FrostFS) GetObject(ctx context.Context, prm layer.PrmObjectGet) (*layer.Object, error) {
 	var addr oid.Address
 	addr.SetContainer(prm.Container)
@@ -308,7 +312,7 @@ func (x *FrostFS) GetObject(ctx context.Context, prm layer.PrmObjectGet) (*layer
 	}, nil
 }
 
-// RangeObject implements frostfs.FrostFS interface method.
+// RangeObject implements layer.FrostFS interface method.
 func (x *FrostFS) RangeObject(ctx context.Context, prm layer.PrmObjectRange) (io.ReadCloser, error) {
 	var addr oid.Address
 	addr.SetContainer(prm.Container)
@@ -333,7 +337,7 @@ func (x *FrostFS) RangeObject(ctx context.Context, prm layer.PrmObjectRange) (io
 	return payloadReader{&res}, nil
 }
 
-// DeleteObject implements frostfs.FrostFS interface method.
+// DeleteObject implements layer.FrostFS interface method.
 func (x *FrostFS) DeleteObject(ctx context.Context, prm layer.PrmObjectDelete) error {
 	var addr oid.Address
 	addr.SetContainer(prm.Container)
@@ -352,7 +356,7 @@ func (x *FrostFS) DeleteObject(ctx context.Context, prm layer.PrmObjectDelete) e
 	return handleObjectError("mark object removal via connection pool", err)
 }
 
-// SearchObjects implements frostfs.FrostFS interface method.
+// SearchObjects implements layer.FrostFS interface method.
 func (x *FrostFS) SearchObjects(ctx context.Context, prm layer.PrmObjectSearch) ([]oid.ID, error) {
 	filters := object.NewSearchFilters()
 	filters.AddRootFilter()
@@ -389,6 +393,16 @@ func (x *FrostFS) SearchObjects(ctx context.Context, prm layer.PrmObjectSearch)
 	return buf, handleObjectError("read object list", err)
 }
 
+// NetworkInfo implements layer.FrostFS interface method.
+func (x *FrostFS) NetworkInfo(ctx context.Context) (netmap.NetworkInfo, error) {
+	ni, err := x.pool.NetworkInfo(ctx)
+	if err != nil {
+		return ni, handleObjectError("get network info via connection pool", err)
+	}
+
+	return ni, nil
+}
+
 // ResolverFrostFS represents virtual connection to the FrostFS network.
 // It implements resolver.FrostFS.
 type ResolverFrostFS struct {

pkg/service/tree/tree.go

@@ -101,6 +101,7 @@ const (
 	etagKV          = "ETag"
 	md5KV           = "MD5"
 	finishedKV      = "Finished"
+	creationEpochKV = "CreationEpoch"
 
 	// keys for lock.
 	isLockKV       = "IsLock"
@@ -273,6 +274,14 @@ func newNodeVersionFromTreeNode(log *zap.Logger, filePath string, treeNode *tree
 		}
 	}
 
+	if creationEpoch, ok := treeNode.Get(creationEpochKV); ok {
+		if epoch, err := strconv.ParseUint(creationEpoch, 10, 64); err != nil {
+			log.Warn(logs.InvalidTreeKV, zap.String(creationEpochKV, creationEpoch), zap.Error(err))
+		} else {
+			version.CreationEpoch = epoch
+		}
+	}
+
 	return version, nil
 }
 
@@ -354,6 +363,14 @@ func newMultipartInfoFromTreeNode(log *zap.Logger, filePath string, treeNode *tr
 		}
 	}
 
+	if creationEpoch, ok := treeNode.Get(creationEpochKV); ok {
+		if epoch, err := strconv.ParseUint(creationEpoch, 10, 64); err != nil {
+			log.Warn(logs.InvalidTreeKV, zap.String(creationEpochKV, creationEpoch), zap.Error(err))
+		} else {
+			multipartInfo.CreationEpoch = epoch
+		}
+	}
+
 	return multipartInfo, nil
 }
 
@@ -389,6 +406,12 @@ func newMultipartInfo(log *zap.Logger, node NodeResponse) (*data.MultipartInfo,
 			} else {
 				multipartInfo.Finished = isFinished
 			}
+		case creationEpochKV:
+			if epoch, err := strconv.ParseUint(string(kv.GetValue()), 10, 64); err != nil {
+				log.Warn(logs.InvalidTreeKV, zap.String(creationEpochKV, string(kv.GetValue())), zap.Error(err))
+			} else {
+				multipartInfo.CreationEpoch = epoch
+			}
 		default:
 			multipartInfo.Meta[kv.GetKey()] = string(kv.GetValue())
 		}
@@ -759,7 +782,7 @@ func (c *Tree) GetVersions(ctx context.Context, bktInfo *data.BucketInfo, filepa
 }
 
 func (c *Tree) GetLatestVersion(ctx context.Context, bktInfo *data.BucketInfo, objectName string) (*data.NodeVersion, error) {
-	meta := []string{oidKV, isCombinedKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV}
+	meta := []string{oidKV, isCombinedKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV, creationEpochKV}
 	path := pathFromName(objectName)
 
 	p := &GetNodesParams{
@@ -1605,10 +1628,11 @@ func (c *Tree) GetObjectTaggingAndLock(ctx context.Context, bktInfo *data.Bucket
 func (c *Tree) addVersion(ctx context.Context, bktInfo *data.BucketInfo, treeID string, version *data.NodeVersion) (uint64, error) {
 	path := pathFromName(version.FilePath)
 	meta := map[string]string{
-		oidKV:       version.OID.EncodeToString(),
+		oidKV:           version.OID.EncodeToString(),
-		FileNameKey: path[len(path)-1],
+		FileNameKey:     path[len(path)-1],
-		ownerKV:     version.Owner.EncodeToString(),
+		ownerKV:         version.Owner.EncodeToString(),
-		createdKV:   strconv.FormatInt(version.Created.UTC().UnixMilli(), 10),
+		createdKV:       strconv.FormatInt(version.Created.UTC().UnixMilli(), 10),
+		creationEpochKV: strconv.FormatUint(version.CreationEpoch, 10),
 	}
 
 	if version.Size > 0 {
@@ -1662,7 +1686,7 @@ func (c *Tree) clearOutdatedVersionInfo(ctx context.Context, bktInfo *data.Bucke
 }
 
 func (c *Tree) getVersions(ctx context.Context, bktInfo *data.BucketInfo, treeID, filepath string, onlyUnversioned bool) ([]*data.NodeVersion, error) {
-	keysToReturn := []string{oidKV, isCombinedKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV}
+	keysToReturn := []string{oidKV, isCombinedKV, isUnversionedKV, isDeleteMarkerKV, etagKV, sizeKV, md5KV, creationEpochKV}
 	path := pathFromName(filepath)
 	p := &GetNodesParams{
 		BktInfo:    bktInfo,
@@ -1720,6 +1744,7 @@ func metaFromMultipart(info *data.MultipartInfo, fileName string) map[string]str
 	if info.Finished {
 		info.Meta[finishedKV] = strconv.FormatBool(info.Finished)
 	}
+	info.Meta[creationEpochKV] = strconv.FormatUint(info.CreationEpoch, 10)
 
 	return info.Meta
 }