Refactor replication resync to be an active process (#14266)

When resync is triggered, walk the bucket namespace and resync objects that are unreplicated. This PR also adds an API to report resync progress.
2025-11-10 22:10:12 -05:00 · 2022-02-10 10:16:52 -08:00
parent a2230868e0
commit ed3418c046
12 changed files with 1717 additions and 139 deletions
--- a/cmd/api-router.go
+++ b/cmd/api-router.go
@@ -343,6 +343,9 @@ func registerAPIRouter(router *mux.Router) {
 		// ListenNotification
 		router.Methods(http.MethodGet).HandlerFunc(
 			collectAPIStats("listennotification", maxClients(gz(httpTraceAll(api.ListenNotificationHandler))))).Queries("events", "{events:.*}")
+		// ResetBucketReplicationStatus - MinIO extension API
+		router.Methods(http.MethodGet).HandlerFunc(
+			collectAPIStats("resetbucketreplicationstatus", maxClients(gz(httpTraceAll(api.ResetBucketReplicationStatusHandler))))).Queries("replication-reset-status", "")

 		// Dummy Bucket Calls
 		// GetBucketACL -- this is a dummy call.
@@ -417,9 +420,10 @@ func registerAPIRouter(router *mux.Router) {
 		// PutBucketNotification
 		router.Methods(http.MethodPut).HandlerFunc(
 			collectAPIStats("putbucketnotification", maxClients(gz(httpTraceAll(api.PutBucketNotificationHandler))))).Queries("notification", "")
-		// ResetBucketReplicationState - MinIO extension API
+		// ResetBucketReplicationStart - MinIO extension API
 		router.Methods(http.MethodPut).HandlerFunc(
-			collectAPIStats("resetbucketreplicationstate", maxClients(gz(httpTraceAll(api.ResetBucketReplicationStateHandler))))).Queries("replication-reset", "")
+			collectAPIStats("resetbucketreplicationstart", maxClients(gz(httpTraceAll(api.ResetBucketReplicationStartHandler))))).Queries("replication-reset", "")
+
 		// PutBucket
 		router.Methods(http.MethodPut).HandlerFunc(
 			collectAPIStats("putbucket", maxClients(gz(httpTraceAll(api.PutBucketHandler)))))
--- a/cmd/bucket-handlers.go
+++ b/cmd/bucket-handlers.go
@@ -1301,7 +1301,7 @@ func (api objectAPIHandlers) DeleteBucketHandler(w http.ResponseWriter, r *http.
 	}

 	globalNotificationSys.DeleteBucketMetadata(ctx, bucket)
-
+	globalReplicationPool.deleteResyncMetadata(ctx, bucket)
 	// Call site replication hook.
 	if err := globalSiteReplicationSys.DeleteBucketHook(ctx, bucket, forceDelete); err != nil {
 		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
@@ -1760,12 +1760,13 @@ func (api objectAPIHandlers) GetBucketReplicationMetricsHandler(w http.ResponseW
 	}
 }

-// ResetBucketReplicationStateHandler - starts a replication reset for all objects in a bucket which
+// ResetBucketReplicationStartHandler - starts a replication reset for all objects in a bucket which
 // qualify for replication and re-sync the object(s) to target, provided ExistingObjectReplication is
 // enabled for the qualifying rule. This API is a MinIO only extension provided for situations where
-// remote target is entirely lost,and previously replicated objects need to be re-synced.
-func (api objectAPIHandlers) ResetBucketReplicationStateHandler(w http.ResponseWriter, r *http.Request) {
-	ctx := newContext(r, w, "ResetBucketReplicationState")
+// remote target is entirely lost,and previously replicated objects need to be re-synced. If resync is
+// already in progress it returns an error
+func (api objectAPIHandlers) ResetBucketReplicationStartHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := newContext(r, w, "ResetBucketReplicationStart")
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

 	vars := mux.Vars(r)
@@ -1789,6 +1790,7 @@ func (api objectAPIHandlers) ResetBucketReplicationStateHandler(w http.ResponseW
 			}), r.URL)
 		}
 	}
+	resetBeforeDate := UTCNow().AddDate(0, 0, -1*int(days/24))

 	objectAPI := api.ObjectAPI()
 	if objectAPI == nil {
@@ -1825,7 +1827,7 @@ func (api objectAPIHandlers) ResetBucketReplicationStateHandler(w http.ResponseW
 	if len(tgtArns) == 0 {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrBadRequest, InvalidArgument{
 			Bucket: bucket,
-			Err:    fmt.Errorf("Remote target ARN %s missing/not eligible for replication resync", arn),
+			Err:    fmt.Errorf("Remote target ARN %s missing or ineligible for replication resync", arn),
 		}), r.URL)
 		return
 	}
@@ -1849,22 +1851,90 @@ func (api objectAPIHandlers) ResetBucketReplicationStateHandler(w http.ResponseW
 		default:
 			writeErrorResponseJSON(ctx, w, toAPIError(ctx, err), r.URL)
 		}
+	}
+	if err := startReplicationResync(ctx, bucket, arn, resetID, resetBeforeDate, objectAPI); err != nil {
+		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrBadRequest, InvalidArgument{
+			Bucket: bucket,
+			Err:    err,
+		}), r.URL)
 		return
 	}
-	targets, err := globalBucketTargetSys.ListBucketTargets(ctx, bucket)
-	if err != nil {
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
-	}
-	tgtBytes, err := json.Marshal(&targets)
-	if err != nil {
-		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErrWithErr(ErrAdminConfigBadJSON, err), r.URL)
-		return
-	}
-	if err = globalBucketMetadataSys.Update(ctx, bucket, bucketTargetsFile, tgtBytes); err != nil {
-		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
-		return
-	}
+
+	data, err := json.Marshal(rinfo)
+	if err != nil {
+		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
+		return
+	}
+	// Write success response.
+	writeSuccessResponseJSON(w, data)
+}
+
+// ResetBucketReplicationStatusHandler - returns the status of replication reset.
+// This API is a MinIO only extension
+func (api objectAPIHandlers) ResetBucketReplicationStatusHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := newContext(r, w, "ResetBucketReplicationStatus")
+	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
+
+	vars := mux.Vars(r)
+	bucket := vars["bucket"]
+	arn := r.URL.Query().Get("arn")
+	var err error
+
+	objectAPI := api.ObjectAPI()
+	if objectAPI == nil {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
+		return
+	}
+
+	if s3Error := checkRequestAuthType(ctx, r, policy.ResetBucketReplicationStateAction, bucket, ""); s3Error != ErrNone {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
+		return
+	}
+
+	// Check if bucket exists.
+	if _, err := objectAPI.GetBucketInfo(ctx, bucket); err != nil {
+		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+		return
+	}
+
+	if _, err := globalBucketMetadataSys.GetReplicationConfig(ctx, bucket); err != nil {
+		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
+		return
+	}
+
+	globalReplicationPool.resyncState.RLock()
+	brs, ok := globalReplicationPool.resyncState.statusMap[bucket]
+	if !ok {
+		brs, err = loadBucketResyncMetadata(ctx, bucket, objectAPI)
+		if err != nil {
+			writeErrorResponse(ctx, w, errorCodes.ToAPIErrWithErr(ErrBadRequest, InvalidArgument{
+				Bucket: bucket,
+				Err:    fmt.Errorf("No replication resync status available for %s", arn),
+			}), r.URL)
+		}
+		return
+	}
+
+	var rinfo ResyncTargetsInfo
+	for tarn, st := range brs.TargetsMap {
+		if arn != "" && tarn != arn {
+			continue
+		}
+		rinfo.Targets = append(rinfo.Targets, ResyncTarget{
+			Arn:             tarn,
+			ResetID:         st.ResyncID,
+			StartTime:       st.StartTime,
+			EndTime:         st.EndTime,
+			ResyncStatus:    st.ResyncStatus.String(),
+			ReplicatedSize:  st.ReplicatedSize,
+			ReplicatedCount: st.ReplicatedCount,
+			FailedSize:      st.FailedSize,
+			FailedCount:     st.FailedCount,
+			Bucket:          st.Bucket,
+			Object:          st.Object,
+		})
+	}
+	globalReplicationPool.resyncState.RUnlock()
 	data, err := json.Marshal(rinfo)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
--- a/cmd/bucket-metadata.go
+++ b/cmd/bucket-metadata.go
@@ -375,6 +375,7 @@ func deleteBucketMetadata(ctx context.Context, obj objectDeleter, bucket string)
 	metadataFiles := []string{
 		dataUsageCacheName,
 		bucketMetadataFile,
+		path.Join(replicationDir, resyncFileName),
 	}
 	for _, metaFile := range metadataFiles {
 		configFile := path.Join(bucketMetaPrefix, bucket, metaFile)
--- a/cmd/bucket-replication-utils.go
+++ b/cmd/bucket-replication-utils.go
@@ -23,6 +23,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"

 	"github.com/minio/minio/internal/bucket/replication"
@@ -576,8 +577,23 @@ type ResyncTargetsInfo struct {

 // ResyncTarget is a struct representing the Target reset ID where target is identified by its Arn
 type ResyncTarget struct {
-	Arn     string `json:"arn"`
-	ResetID string `json:"resetid"`
+	Arn       string    `json:"arn"`
+	ResetID   string    `json:"resetid"`
+	StartTime time.Time `json:"startTime"`
+	EndTime   time.Time `json:"endTime"`
+	// Status of resync operation
+	ResyncStatus string `json:"resyncStatus,omitempty"`
+	// Completed size in bytes
+	ReplicatedSize int64 `json:"completedReplicationSize"`
+	// Failed size in bytes
+	FailedSize int64 `json:"failedReplicationSize"`
+	// Total number of failed operations
+	FailedCount int64 `json:"failedReplicationCount"`
+	// Total number of failed operations
+	ReplicatedCount int64 `json:"replicationCount"`
+	// Last bucket/object replicated.
+	Bucket string `json:"bucket,omitempty"`
+	Object string `json:"object,omitempty"`
 }

 // VersionPurgeStatusType represents status of a versioned delete or permanent delete w.r.t bucket replication
@@ -603,3 +619,83 @@ func (v VersionPurgeStatusType) Empty() bool {
 func (v VersionPurgeStatusType) Pending() bool {
 	return v == Pending || v == Failed
 }
+
+type replicationResyncState struct {
+	// map of bucket to their resync status
+	statusMap map[string]BucketReplicationResyncStatus
+	sync.RWMutex
+}
+
+const (
+	replicationDir      = "replication"
+	resyncFileName      = "resync.bin"
+	resyncMetaFormat    = 1
+	resyncMetaVersionV1 = 1
+	resyncMetaVersion   = resyncMetaVersionV1
+)
+
+// ResyncStatusType status of resync operation
+type ResyncStatusType int
+
+const (
+	// NoResync - no resync in progress
+	NoResync ResyncStatusType = iota
+	// ResyncStarted -  resync in progress
+	ResyncStarted
+	// ResyncCompleted -  resync finished
+	ResyncCompleted
+	// ResyncFailed -  resync failed
+	ResyncFailed
+)
+
+func (rt ResyncStatusType) String() string {
+	switch rt {
+	case ResyncStarted:
+		return "Ongoing"
+	case ResyncCompleted:
+		return "Completed"
+	case ResyncFailed:
+		return "Failed"
+	default:
+		return ""
+	}
+}
+
+// TargetReplicationResyncStatus status of resync of bucket for a specific target
+type TargetReplicationResyncStatus struct {
+	StartTime time.Time `json:"startTime" msg:"st"`
+	EndTime   time.Time `json:"endTime" msg:"et"`
+	// Resync ID assigned to this reset
+	ResyncID string `json:"resyncID" msg:"id"`
+	// ResyncBeforeDate - resync all objects created prior to this date
+	ResyncBeforeDate time.Time `json:"resyncBeforeDate" msg:"rdt"`
+	// Status of resync operation
+	ResyncStatus ResyncStatusType `json:"resyncStatus" msg:"rst"`
+	// Failed size in bytes
+	FailedSize int64 `json:"failedReplicationSize"  msg:"fs"`
+	// Total number of failed operations
+	FailedCount int64 `json:"failedReplicationCount"  msg:"frc"`
+	// Completed size in bytes
+	ReplicatedSize int64 `json:"completedReplicationSize"  msg:"rs"`
+	// Total number of failed operations
+	ReplicatedCount int64 `json:"replicationCount"  msg:"rrc"`
+	// Last bucket/object replicated.
+	Bucket string `json:"-" msg:"bkt"`
+	Object string `json:"-" msg:"obj"`
+}
+
+// BucketReplicationResyncStatus captures current replication resync status
+type BucketReplicationResyncStatus struct {
+	Version int `json:"version" msg:"v"`
+	// map of remote arn to their resync status for a bucket
+	TargetsMap map[string]TargetReplicationResyncStatus `json:"resyncMap,omitempty" msg:"brs"`
+	ID         int                                      `json:"id" msg:"id"`
+	LastUpdate time.Time                                `json:"lastUpdate" msg:"lu"`
+}
+
+func newBucketResyncStatus(bucket string) BucketReplicationResyncStatus {
+	return BucketReplicationResyncStatus{
+		TargetsMap: make(map[string]TargetReplicationResyncStatus),
+		Version:    resyncMetaVersion,
+	}
+}
--- a/cmd/bucket-replication-utils_gen.go
+++ b/cmd/bucket-replication-utils_gen.go
--- a/cmd/bucket-replication-utils_gen_test.go
+++ b/cmd/bucket-replication-utils_gen_test.go
@@ -9,6 +9,119 @@ import (
 	"github.com/tinylib/msgp/msgp"
 )

+func TestMarshalUnmarshalBucketReplicationResyncStatus(t *testing.T) {
+	v := BucketReplicationResyncStatus{}
+	bts, err := v.MarshalMsg(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	left, err := v.UnmarshalMsg(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after UnmarshalMsg(): %q", len(left), left)
+	}
+
+	left, err = msgp.Skip(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after Skip(): %q", len(left), left)
+	}
+}
+
+func BenchmarkMarshalMsgBucketReplicationResyncStatus(b *testing.B) {
+	v := BucketReplicationResyncStatus{}
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.MarshalMsg(nil)
+	}
+}
+
+func BenchmarkAppendMsgBucketReplicationResyncStatus(b *testing.B) {
+	v := BucketReplicationResyncStatus{}
+	bts := make([]byte, 0, v.Msgsize())
+	bts, _ = v.MarshalMsg(bts[0:0])
+	b.SetBytes(int64(len(bts)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bts, _ = v.MarshalMsg(bts[0:0])
+	}
+}
+
+func BenchmarkUnmarshalBucketReplicationResyncStatus(b *testing.B) {
+	v := BucketReplicationResyncStatus{}
+	bts, _ := v.MarshalMsg(nil)
+	b.ReportAllocs()
+	b.SetBytes(int64(len(bts)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := v.UnmarshalMsg(bts)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func TestEncodeDecodeBucketReplicationResyncStatus(t *testing.T) {
+	v := BucketReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+
+	m := v.Msgsize()
+	if buf.Len() > m {
+		t.Log("WARNING: TestEncodeDecodeBucketReplicationResyncStatus Msgsize() is inaccurate")
+	}
+
+	vn := BucketReplicationResyncStatus{}
+	err := msgp.Decode(&buf, &vn)
+	if err != nil {
+		t.Error(err)
+	}
+
+	buf.Reset()
+	msgp.Encode(&buf, &v)
+	err = msgp.NewReader(&buf).Skip()
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func BenchmarkEncodeBucketReplicationResyncStatus(b *testing.B) {
+	v := BucketReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	en := msgp.NewWriter(msgp.Nowhere)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.EncodeMsg(en)
+	}
+	en.Flush()
+}
+
+func BenchmarkDecodeBucketReplicationResyncStatus(b *testing.B) {
+	v := BucketReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	rd := msgp.NewEndlessReader(buf.Bytes(), b)
+	dc := msgp.NewReader(rd)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		err := v.DecodeMsg(dc)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
 func TestMarshalUnmarshalReplicateDecision(t *testing.T) {
 	v := ReplicateDecision{}
 	bts, err := v.MarshalMsg(nil)
@@ -686,3 +799,116 @@ func BenchmarkDecodeResyncTargetsInfo(b *testing.B) {
 		}
 	}
 }
+
+func TestMarshalUnmarshalTargetReplicationResyncStatus(t *testing.T) {
+	v := TargetReplicationResyncStatus{}
+	bts, err := v.MarshalMsg(nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	left, err := v.UnmarshalMsg(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after UnmarshalMsg(): %q", len(left), left)
+	}
+
+	left, err = msgp.Skip(bts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) > 0 {
+		t.Errorf("%d bytes left over after Skip(): %q", len(left), left)
+	}
+}
+
+func BenchmarkMarshalMsgTargetReplicationResyncStatus(b *testing.B) {
+	v := TargetReplicationResyncStatus{}
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.MarshalMsg(nil)
+	}
+}
+
+func BenchmarkAppendMsgTargetReplicationResyncStatus(b *testing.B) {
+	v := TargetReplicationResyncStatus{}
+	bts := make([]byte, 0, v.Msgsize())
+	bts, _ = v.MarshalMsg(bts[0:0])
+	b.SetBytes(int64(len(bts)))
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		bts, _ = v.MarshalMsg(bts[0:0])
+	}
+}
+
+func BenchmarkUnmarshalTargetReplicationResyncStatus(b *testing.B) {
+	v := TargetReplicationResyncStatus{}
+	bts, _ := v.MarshalMsg(nil)
+	b.ReportAllocs()
+	b.SetBytes(int64(len(bts)))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, err := v.UnmarshalMsg(bts)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func TestEncodeDecodeTargetReplicationResyncStatus(t *testing.T) {
+	v := TargetReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+
+	m := v.Msgsize()
+	if buf.Len() > m {
+		t.Log("WARNING: TestEncodeDecodeTargetReplicationResyncStatus Msgsize() is inaccurate")
+	}
+
+	vn := TargetReplicationResyncStatus{}
+	err := msgp.Decode(&buf, &vn)
+	if err != nil {
+		t.Error(err)
+	}
+
+	buf.Reset()
+	msgp.Encode(&buf, &v)
+	err = msgp.NewReader(&buf).Skip()
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func BenchmarkEncodeTargetReplicationResyncStatus(b *testing.B) {
+	v := TargetReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	en := msgp.NewWriter(msgp.Nowhere)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		v.EncodeMsg(en)
+	}
+	en.Flush()
+}
+
+func BenchmarkDecodeTargetReplicationResyncStatus(b *testing.B) {
+	v := TargetReplicationResyncStatus{}
+	var buf bytes.Buffer
+	msgp.Encode(&buf, &v)
+	b.SetBytes(int64(buf.Len()))
+	rd := msgp.NewEndlessReader(buf.Bytes(), b)
+	dc := msgp.NewReader(rd)
+	b.ReportAllocs()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		err := v.DecodeMsg(dc)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
--- a/cmd/bucket-replication.go
+++ b/cmd/bucket-replication.go
@@ -19,10 +19,13 @@ package cmd

 import (
 	"context"
+	"encoding/binary"
+	"errors"
 	"fmt"
 	"io"
 	"math"
 	"net/http"
+	"path"
 	"reflect"
 	"strings"
 	"sync"
@@ -998,6 +1001,7 @@ func replicateObjectToTarget(ctx context.Context, ri ReplicateObjectInfo, object
 		OpType:                ri.OpType,
 		ReplicationAction:     rAction,
 	}
+
 	if ri.ObjectInfo.TargetReplicationStatus(tgt.ARN) == replication.Completed && !ri.ExistingObjResync.Empty() && !ri.ExistingObjResync.mustResyncTarget(tgt.ARN) {
 		rinfo.ReplicationStatus = replication.Completed
 		rinfo.ReplicationResynced = true
@@ -1057,6 +1061,13 @@ func replicateObjectToTarget(ctx context.Context, ri ReplicateObjectInfo, object
 		})
 		return rinfo
 	}
+	defer func() {
+		if rinfo.ReplicationStatus == replication.Completed && ri.OpType == replication.ExistingObjectReplicationType && tgt.ResetID != "" {
+			rinfo.ResyncTimestamp = fmt.Sprintf("%s;%s", UTCNow().Format(http.TimeFormat), tgt.ResetID)
+			rinfo.ReplicationResynced = true
+		}
+		rinfo.Duration = time.Since(startTime)
+	}()

 	rAction = replicateAll
 	oi, cerr := tgt.StatObject(ctx, tgt.Bucket, object, miniogo.StatObjectOptions{
@@ -1089,13 +1100,8 @@ func replicateObjectToTarget(ctx context.Context, ri ReplicateObjectInfo, object
 				// Note: Replication Stats would have been updated despite metadata update failure.
 				gr.Close()
 				closeOnDefer = false
-				return replicatedTargetInfo{
-					ReplicationStatus:     replication.Completed,
-					Size:                  sz,
-					Arn:                   tgt.ARN,
-					ReplicationAction:     rAction,
-					PrevReplicationStatus: objInfo.TargetReplicationStatus(tgt.ARN),
-				}
+				rinfo.ReplicationAction = rAction
+				rinfo.ReplicationStatus = replication.Completed
 			}
 			return
 		}
@@ -1103,13 +1109,6 @@ func replicateObjectToTarget(ctx context.Context, ri ReplicateObjectInfo, object
 	rinfo.ReplicationStatus = replication.Completed
 	rinfo.Size = size
 	rinfo.ReplicationAction = rAction
-	defer func() {
-		if rinfo.ReplicationStatus == replication.Completed && ri.OpType == replication.ExistingObjectReplicationType && tgt.ResetID != "" {
-			rinfo.ResyncTimestamp = fmt.Sprintf("%s;%s", UTCNow().Format(http.TimeFormat), tgt.ResetID)
-			rinfo.ReplicationResynced = true
-		}
-		rinfo.Duration = time.Since(startTime)
-	}()
 	// use core client to avoid doing multipart on PUT
 	c := &miniogo.Core{Client: tgt.Client}
 	if rAction != replicateAll {
@@ -1308,6 +1307,7 @@ type ReplicationPool struct {
 	existingReplicaDeleteCh chan DeletedObjectReplicationInfo
 	workerSize              int
 	mrfWorkerSize           int
+	resyncState             replicationResyncState
 	workerWg                sync.WaitGroup
 	mrfWorkerWg             sync.WaitGroup
 	once                    sync.Once
@@ -1324,6 +1324,7 @@ func NewReplicationPool(ctx context.Context, o ObjectLayer, opts replicationPool
 		mrfWorkerKillCh:         make(chan struct{}, opts.FailedWorkers),
 		existingReplicaCh:       make(chan ReplicateObjectInfo, 100000),
 		existingReplicaDeleteCh: make(chan DeletedObjectReplicationInfo, 100000),
+		resyncState:             replicationResyncState{statusMap: make(map[string]BucketReplicationResyncStatus)},
 		ctx:                     ctx,
 		objLayer:                o,
 	}
@@ -1331,6 +1332,7 @@ func NewReplicationPool(ctx context.Context, o ObjectLayer, opts replicationPool
 	pool.ResizeWorkers(opts.Workers)
 	pool.ResizeFailedWorkers(opts.FailedWorkers)
 	go pool.AddExistingObjectReplicateWorker()
+	go pool.periodicResyncMetaSave(ctx, o)
 	return pool
 }

@@ -1870,3 +1872,333 @@ func getLatestReplicationStats(bucket string, u BucketUsageInfo) (s BucketReplic
 	s.ReplicatedSize = int64(math.Max(float64(s.ReplicatedSize), float64(latestTotReplicatedSize)))
 	return s
 }
+
+const resyncTimeInterval = time.Minute * 10
+
+// periodicResyncMetaSave saves in-memory resync meta stats to disk in periodic intervals
+func (p *ReplicationPool) periodicResyncMetaSave(ctx context.Context, objectAPI ObjectLayer) {
+	resyncTimer := time.NewTimer(resyncTimeInterval)
+	defer resyncTimer.Stop()
+
+	for {
+		select {
+		case <-resyncTimer.C:
+			resyncTimer.Reset(resyncTimeInterval)
+			now := UTCNow()
+			p.resyncState.RLock()
+			for bucket, brs := range p.resyncState.statusMap {
+				var updt bool
+				for _, st := range brs.TargetsMap {
+					// if resync in progress or just ended, needs to save to disk
+					if st.EndTime.Equal(timeSentinel) || now.Sub(st.EndTime) <= resyncTimeInterval {
+						updt = true
+						break
+					}
+				}
+				if updt {
+					brs.LastUpdate = now
+					if err := saveResyncStatus(ctx, bucket, brs, objectAPI); err != nil {
+						logger.LogIf(ctx, fmt.Errorf("Could not save resync metadata to disk for %s - %w", bucket, err))
+						continue
+					}
+				}
+			}
+			p.resyncState.RUnlock()
+		case <-ctx.Done():
+			// server could be restarting - need
+			// to exit immediately
+			return
+		}
+	}
+}
+
+// resyncBucket resyncs all qualifying objects as per replication rules for the target
+// ARN
+func resyncBucket(ctx context.Context, bucket, arn string, heal bool, objectAPI ObjectLayer) {
+	resyncStatus := ResyncFailed
+	defer func() {
+		globalReplicationPool.resyncState.Lock()
+		m := globalReplicationPool.resyncState.statusMap[bucket]
+		st := m.TargetsMap[arn]
+		st.EndTime = UTCNow()
+		st.ResyncStatus = resyncStatus
+		m.TargetsMap[arn] = st
+		globalReplicationPool.resyncState.Unlock()
+	}()
+	// Allocate new results channel to receive ObjectInfo.
+	objInfoCh := make(chan ObjectInfo)
+	cfg, err := getReplicationConfig(ctx, bucket)
+	if err != nil {
+		logger.LogIf(ctx, fmt.Errorf("Replication resync of %s for arn %s failed with %w", bucket, arn, err))
+		return
+	}
+	tgts, err := globalBucketTargetSys.ListBucketTargets(ctx, bucket)
+	if err != nil {
+		logger.LogIf(ctx, fmt.Errorf("Replication resync of %s for arn %s failed  %w", bucket, arn, err))
+		return
+	}
+	rcfg := replicationConfig{
+		Config:  cfg,
+		remotes: tgts,
+	}
+	tgtArns := cfg.FilterTargetArns(
+		replication.ObjectOpts{
+			OpType:    replication.ResyncReplicationType,
+			TargetArn: arn,
+		})
+	if len(tgtArns) != 1 {
+		logger.LogIf(ctx, fmt.Errorf("Replication resync failed for %s - arn specified %s is missing in the replication config", bucket, arn))
+		return
+	}
+	tgt := globalBucketTargetSys.GetRemoteTargetClient(ctx, arn)
+	if tgt == nil {
+		logger.LogIf(ctx, fmt.Errorf("Replication resync failed for %s - target could not be created for arn %s", bucket, arn))
+		return
+	}
+
+	// Walk through all object versions - note ascending order of walk needed to ensure delete marker replicated to
+	// target after object version is first created.
+	if err := objectAPI.Walk(ctx, bucket, "", objInfoCh, ObjectOptions{WalkAscending: true}); err != nil {
+		logger.LogIf(ctx, err)
+		return
+	}
+
+	globalReplicationPool.resyncState.RLock()
+	m := globalReplicationPool.resyncState.statusMap[bucket]
+	st := m.TargetsMap[arn]
+	globalReplicationPool.resyncState.RUnlock()
+	var lastCheckpoint string
+	if st.ResyncStatus == ResyncStarted || st.ResyncStatus == ResyncFailed {
+		lastCheckpoint = st.Object
+	}
+	for obj := range objInfoCh {
+		if heal && lastCheckpoint != "" && lastCheckpoint != obj.Name {
+			continue
+		}
+		lastCheckpoint = ""
+
+		roi := getHealReplicateObjectInfo(obj, rcfg)
+		if !roi.ExistingObjResync.mustResync() {
+			continue
+		}
+
+		if roi.DeleteMarker || !roi.VersionPurgeStatus.Empty() {
+
+			versionID := ""
+			dmVersionID := ""
+			if roi.VersionPurgeStatus.Empty() {
+				dmVersionID = roi.VersionID
+			} else {
+				versionID = roi.VersionID
+			}
+
+			doi := DeletedObjectReplicationInfo{
+				DeletedObject: DeletedObject{
+					ObjectName:            roi.Name,
+					DeleteMarkerVersionID: dmVersionID,
+					VersionID:             versionID,
+					ReplicationState:      roi.getReplicationState(roi.Dsc.String(), versionID, true),
+					DeleteMarkerMTime:     DeleteMarkerMTime{roi.ModTime},
+					DeleteMarker:          roi.DeleteMarker,
+				},
+				Bucket: roi.Bucket,
+				OpType: replication.ExistingObjectReplicationType,
+			}
+			replicateDelete(ctx, doi, objectAPI, ReplicateDelete)
+		} else {
+			roi.OpType = replication.ExistingObjectReplicationType
+			replicateObject(ctx, roi, objectAPI, ReplicateExisting)
+		}
+		_, err = tgt.StatObject(ctx, tgt.Bucket, roi.Name, miniogo.StatObjectOptions{
+			VersionID: roi.VersionID,
+			Internal: miniogo.AdvancedGetOptions{
+				ReplicationProxyRequest: "false",
+			},
+		})
+		globalReplicationPool.resyncState.Lock()
+		m = globalReplicationPool.resyncState.statusMap[bucket]
+		st = m.TargetsMap[arn]
+		st.Object = roi.Name
+		if err != nil {
+			if roi.DeleteMarker && isErrMethodNotAllowed(ErrorRespToObjectError(err, bucket, roi.Name)) {
+				st.ReplicatedCount++
+			} else {
+				st.FailedCount++
+			}
+		} else {
+			st.ReplicatedCount++
+			st.ReplicatedSize += roi.Size
+		}
+		m.TargetsMap[arn] = st
+		globalReplicationPool.resyncState.Unlock()
+	}
+	resyncStatus = ResyncCompleted
+}
+
+// start replication resync for the remote target ARN specified
+func startReplicationResync(ctx context.Context, bucket, arn, resyncID string, resyncBeforeDate time.Time, objAPI ObjectLayer) error {
+	if bucket == "" {
+		return fmt.Errorf("bucket name is empty")
+	}
+	if arn == "" {
+		return fmt.Errorf("target ARN specified for resync is empty")
+	}
+	// Check if the current bucket has quota restrictions, if not skip it
+	cfg, err := getReplicationConfig(ctx, bucket)
+	if err != nil {
+		return err
+	}
+	tgtArns := cfg.FilterTargetArns(
+		replication.ObjectOpts{
+			OpType:    replication.ResyncReplicationType,
+			TargetArn: arn,
+		})
+
+	if len(tgtArns) == 0 {
+		return fmt.Errorf("arn %s specified for resync not found in replication config", arn)
+	}
+
+	data, err := loadBucketResyncMetadata(ctx, bucket, objAPI)
+	if err != nil {
+		return err
+	}
+	// validate if resync is in progress for this arn
+	for tArn, st := range data.TargetsMap {
+		if arn == tArn && st.ResyncStatus == ResyncStarted {
+			return fmt.Errorf("Resync of bucket %s is already in progress for remote bucket %s", bucket, arn)
+		}
+	}
+
+	status := TargetReplicationResyncStatus{
+		ResyncID:         resyncID,
+		ResyncBeforeDate: resyncBeforeDate,
+		StartTime:        UTCNow(),
+		ResyncStatus:     ResyncStarted,
+		Bucket:           bucket,
+	}
+	data.TargetsMap[arn] = status
+	if err = saveResyncStatus(ctx, bucket, data, objAPI); err != nil {
+		return err
+	}
+	globalReplicationPool.resyncState.Lock()
+	defer globalReplicationPool.resyncState.Unlock()
+	brs, ok := globalReplicationPool.resyncState.statusMap[bucket]
+	if !ok {
+		brs = BucketReplicationResyncStatus{
+			Version:    resyncMetaVersion,
+			TargetsMap: make(map[string]TargetReplicationResyncStatus),
+		}
+	}
+	brs.TargetsMap[arn] = status
+	globalReplicationPool.resyncState.statusMap[bucket] = brs
+	go resyncBucket(GlobalContext, bucket, arn, false, objAPI)
+	return nil
+}
+
+// delete resync metadata from replication resync state in memory
+func (p *ReplicationPool) deleteResyncMetadata(ctx context.Context, bucket string) {
+	if p == nil {
+		return
+	}
+	p.resyncState.Lock()
+	delete(p.resyncState.statusMap, bucket)
+	defer p.resyncState.Unlock()
+}
+
+// initResync - initializes bucket replication resync for all buckets.
+func (p *ReplicationPool) initResync(ctx context.Context, buckets []BucketInfo, objAPI ObjectLayer) error {
+	if objAPI == nil {
+		return errServerNotInitialized
+	}
+	// replication applies only to erasure coded setups
+	if !globalIsErasure {
+		return nil
+	}
+	// Load bucket metadata sys in background
+	go p.loadResync(ctx, buckets, objAPI)
+	return nil
+}
+
+// Loads bucket replication resync statuses into memory.
+func (p *ReplicationPool) loadResync(ctx context.Context, buckets []BucketInfo, objAPI ObjectLayer) {
+	for index := range buckets {
+		meta, err := loadBucketResyncMetadata(ctx, buckets[index].Name, objAPI)
+		if err != nil {
+			if errors.Is(err, errVolumeNotFound) {
+				meta = newBucketResyncStatus(buckets[index].Name)
+			} else {
+				logger.LogIf(ctx, err)
+				continue
+			}
+		}
+		p.resyncState.statusMap[buckets[index].Name] = meta
+	}
+	for index := range buckets {
+		bucket := buckets[index].Name
+		m, ok := p.resyncState.statusMap[bucket]
+		if ok {
+			for arn, st := range m.TargetsMap {
+				if st.ResyncStatus == ResyncFailed || st.ResyncStatus == ResyncStarted {
+					go resyncBucket(ctx, bucket, arn, true, objAPI)
+				}
+			}
+		}
+	}
+}
+
+// load bucket resync metadata from disk
+func loadBucketResyncMetadata(ctx context.Context, bucket string, objAPI ObjectLayer) (brs BucketReplicationResyncStatus, e error) {
+	brs = newBucketResyncStatus(bucket)
+
+	resyncDirPath := path.Join(bucketMetaPrefix, bucket, replicationDir)
+	data, err := readConfig(GlobalContext, objAPI, pathJoin(resyncDirPath, resyncFileName))
+	if err != nil && err != errConfigNotFound {
+		return brs, err
+	}
+	if len(data) == 0 {
+		// Seems to be empty.
+		return brs, nil
+	}
+	if len(data) <= 4 {
+		return brs, fmt.Errorf("replication resync: no data")
+	}
+	// Read resync meta header
+	switch binary.LittleEndian.Uint16(data[0:2]) {
+	case resyncMetaFormat:
+	default:
+		return brs, fmt.Errorf("resyncMeta: unknown format: %d", binary.LittleEndian.Uint16(data[0:2]))
+	}
+	switch binary.LittleEndian.Uint16(data[2:4]) {
+	case resyncMetaVersion:
+	default:
+		return brs, fmt.Errorf("resyncMeta: unknown version: %d", binary.LittleEndian.Uint16(data[2:4]))
+	}
+	// OK, parse data.
+	if _, err = brs.UnmarshalMsg(data[4:]); err != nil {
+		return brs, err
+	}
+
+	switch brs.Version {
+	case resyncMetaVersionV1:
+	default:
+		return brs, fmt.Errorf("unexpected resync meta version: %d", brs.Version)
+	}
+	return brs, nil
+}
+
+// save resync status to resync.bin
+func saveResyncStatus(ctx context.Context, bucket string, brs BucketReplicationResyncStatus, objectAPI ObjectLayer) error {
+	data := make([]byte, 4, brs.Msgsize()+4)
+
+	// Initialize the resync meta header.
+	binary.LittleEndian.PutUint16(data[0:2], resyncMetaFormat)
+	binary.LittleEndian.PutUint16(data[2:4], resyncMetaVersion)
+
+	buf, err := brs.MarshalMsg(data)
+	if err != nil {
+		return err
+	}
+
+	configFile := path.Join(bucketMetaPrefix, bucket, replicationDir, resyncFileName)
+	return saveConfig(ctx, objectAPI, configFile, buf)
+}
--- a/cmd/erasure-server-pool.go
+++ b/cmd/erasure-server-pool.go
@@ -1668,7 +1668,13 @@ func (z *erasureServerPools) Walk(ctx context.Context, bucket, prefix string, re
 							cancel()
 							return
 						}
-
+						if opts.WalkAscending {
+							for i := len(fivs.Versions) - 1; i >= 0; i-- {
+								version := fivs.Versions[i]
+								results <- version.ToObjectInfo(bucket, version.Name)
+							}
+							return
+						}
 						for _, version := range fivs.Versions {
 							results <- version.ToObjectInfo(bucket, version.Name)
 						}
--- a/cmd/object-api-interface.go
+++ b/cmd/object-api-interface.go
@@ -72,7 +72,8 @@ type ObjectOptions struct {
 	MaxParity bool

 	// Mutate set to 'true' if the call is namespace mutation call
-	Mutate bool
+	Mutate        bool
+	WalkAscending bool // return Walk results in ascending order of versions
 }

 // ExpirationOptions represents object options for object expiration at objectLayer.
--- a/cmd/server-main.go
+++ b/cmd/server-main.go
@@ -577,6 +577,8 @@ func serverMain(ctx *cli.Context) {
 		if err != nil {
 			logger.LogIf(GlobalContext, fmt.Errorf("Unable to list buckets to heal: %w", err))
 		}
+		// initialize replication resync state.
+		go globalReplicationPool.initResync(GlobalContext, buckets, newObject)

 		// Populate existing buckets to the etcd backend
 		if globalDNSConfig != nil {