feat: add idempotent delete marker support (#15521)

The bottom line is delete markers are a nuisance,
most applications are not version aware and this
has simply complicated the version management.

AWS S3 gave an unnecessary complication overhead
for customers, they need to now manage these
markers by applying ILM settings and clean
them up on a regular basis.

To make matters worse all these delete markers
get replicated as well in a replicated setup,
requiring two ILM settings on each site.

This PR is an attempt to address this inferior
implementation by deviating MinIO towards an
idempotent delete marker implementation i.e
MinIO will never create any more than single
consecutive delete markers.

This significantly reduces operational overhead
by making versioning more useful for real data.

This is an S3 spec deviation for pragmatic reasons.

.github/workflows/go-fips.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        go-version: [1.17.11b7, 1.18.3b7]
+        go-version: [1.18.5b7]
         os: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v2

cmd/erasure-object.go

@@ -448,15 +448,26 @@ func (er erasureObjects) deleteIfDangling(ctx context.Context, bucket, object st
 		}
 		defer NSUpdated(bucket, object)
 
-		if opts.VersionID != "" {
+		fi := FileInfo{
-			er.deleteObjectVersion(ctx, bucket, object, 1, FileInfo{
-				VersionID: opts.VersionID,
-			}, false)
-		} else {
-			er.deleteObjectVersion(ctx, bucket, object, 1, FileInfo{
 			VersionID: m.VersionID,
-			}, false)
 		}
+		if opts.VersionID != "" {
+			fi.VersionID = opts.VersionID
+		}
+
+		disks := er.getDisks()
+		g := errgroup.WithNErrs(len(disks))
+		for index := range disks {
+			index := index
+			g.Go(func() error {
+				if disks[index] == nil {
+					return errDiskNotFound
+				}
+				return disks[index].DeleteVersion(ctx, bucket, object, fi, false)
+			}, index)
+		}
+
+		g.Wait()
 	}
 	return m, err
 }
@@ -1172,8 +1183,16 @@ func (er erasureObjects) putObject(ctx context.Context, bucket string, object st
 	return fi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
 }
 
-func (er erasureObjects) deleteObjectVersion(ctx context.Context, bucket, object string, writeQuorum int, fi FileInfo, forceDelMarker bool) error {
+func (er erasureObjects) deleteObjectVersion(ctx context.Context, bucket, object string, fi FileInfo, forceDelMarker bool) error {
 	disks := er.getDisks()
+	// Assume (N/2 + 1) quorum for Delete()
+	// this is a theoretical assumption such that
+	// for delete's we do not need to honor storage
+	// class for objects that have reduced quorum
+	// due to storage class - this only needs to be honored
+	// for Read() requests alone that we already do.
+	writeQuorum := len(disks)/2 + 1
+
 	g := errgroup.WithNErrs(len(disks))
 	for index := range disks {
 		index := index
@@ -1423,32 +1442,14 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		}
 	}
 
-	// Acquire a write lock before deleting the object.
-	lk := er.NewNSLock(bucket, object)
-	lkctx, err := lk.GetLock(ctx, globalDeleteOperationTimeout)
-	if err != nil {
-		return ObjectInfo{}, err
-	}
-	ctx = lkctx.Context()
-	defer lk.Unlock(lkctx.Cancel)
-
-	versionFound := true
 	objInfo = ObjectInfo{VersionID: opts.VersionID} // version id needed in Delete API response.
-	goi, writeQuorum, gerr := er.getObjectInfoAndQuorum(ctx, bucket, object, opts)
+	defer NSUpdated(bucket, object)
-	if gerr != nil && goi.Name == "" {
+
-		switch gerr.(type) {
+	storageDisks := er.getDisks()
-		case InsufficientReadQuorum:
-			return objInfo, InsufficientWriteQuorum{}
-		}
-		// For delete marker replication, versionID being replicated will not exist on disk
-		if opts.DeleteMarker {
-			versionFound = false
-		} else {
-			return objInfo, gerr
-		}
-	}
 
 	if opts.Expiration.Expire {
+		goi, _, err := er.getObjectInfoAndQuorum(ctx, bucket, object, opts)
+		if err == nil {
 			action := evalActionFromLifecycle(ctx, *lc, rcfg, goi, false)
 			var isErr bool
 			switch action {
@@ -1471,21 +1472,19 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 				}
 			}
 		}
-
-	defer NSUpdated(bucket, object)
-
-	storageDisks := er.getDisks()
-
-	var markDelete bool
-	// Determine whether to mark object deleted for replication
-	if goi.VersionID != "" {
-		markDelete = true
 	}
 
-	// Default deleteMarker to true if object is under versioning
+	versionFound := !(opts.DeleteMarker && opts.VersionID != "")
-	deleteMarker := opts.Versioned
 
-	if opts.VersionID != "" {
+	// Determine whether to mark object deleted for replication
+	markDelete := !opts.DeleteMarker && opts.VersionID != ""
+
+	// Default deleteMarker to true if object is under versioning
+	// versioning suspended means we add `null` version as
+	// delete marker, if its not decided already.
+	deleteMarker := (opts.Versioned || opts.VersionSuspended) && opts.VersionID == "" || (opts.DeleteMarker && opts.VersionID != "")
+
+	if markDelete {
 		// case where replica version needs to be deleted on target cluster
 		if versionFound && opts.DeleteMarkerReplicationStatus() == replication.Replica {
 			markDelete = false
@@ -1496,22 +1495,6 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		if opts.VersionPurgeStatus() == Complete {
 			markDelete = false
 		}
-
-		// Version is found but we do not wish to create more delete markers
-		// now, since VersionPurgeStatus() is already set, we can let the
-		// lower layers decide this. This fixes a regression that was introduced
-		// in PR #14555 where !VersionPurgeStatus.Empty() is automatically
-		// considered as Delete marker true to avoid listing such objects by
-		// regular ListObjects() calls. However for delete replication this
-		// ends up being a problem because "upon" a successful delete this
-		// ends up creating a new delete marker that is spurious and unnecessary.
-		if versionFound {
-			if !goi.VersionPurgeStatus.Empty() {
-				deleteMarker = false
-			} else if !goi.DeleteMarker { // implies a versioned delete of object
-				deleteMarker = false
-			}
-		}
 	}
 
 	modTime := opts.MTime
@@ -1519,13 +1502,7 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		modTime = UTCNow()
 	}
 	fvID := mustGetUUID()
-	if markDelete {
+	if markDelete && (opts.Versioned || opts.VersionSuspended) {
-		if opts.Versioned || opts.VersionSuspended {
-			if !deleteMarker {
-				// versioning suspended means we add `null` version as
-				// delete marker, if its not decided already.
-				deleteMarker = opts.VersionSuspended && opts.VersionID == ""
-			}
 		fi := FileInfo{
 			Name:             object,
 			Deleted:          deleteMarker,
@@ -1546,12 +1523,11 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		// delete marker. Add delete marker, since we don't have
 		// any version specified explicitly. Or if a particular
 		// version id needs to be replicated.
-			if err = er.deleteObjectVersion(ctx, bucket, object, writeQuorum, fi, opts.DeleteMarker); err != nil {
+		if err = er.deleteObjectVersion(ctx, bucket, object, fi, opts.DeleteMarker); err != nil {
 			return objInfo, toObjectErr(err, bucket, object)
 		}
 		return fi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
 	}
-	}
 
 	// Delete the object version on all disks.
 	dfi := FileInfo{
@@ -1565,7 +1541,7 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		ExpireRestored:   opts.Transition.ExpireRestored,
 	}
 	dfi.SetTierFreeVersionID(fvID)
-	if err = er.deleteObjectVersion(ctx, bucket, object, writeQuorum, dfi, opts.DeleteMarker); err != nil {
+	if err = er.deleteObjectVersion(ctx, bucket, object, dfi, opts.DeleteMarker); err != nil {
 		return objInfo, toObjectErr(err, bucket, object)
 	}
 
@@ -1577,13 +1553,7 @@ func (er erasureObjects) DeleteObject(ctx context.Context, bucket, object string
 		break
 	}
 
-	return ObjectInfo{
+	return dfi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
-		Bucket:                     bucket,
-		Name:                       object,
-		VersionID:                  opts.VersionID,
-		VersionPurgeStatusInternal: opts.DeleteReplication.VersionPurgeStatusInternal,
-		ReplicationStatusInternal:  opts.DeleteReplication.ReplicationStatusInternal,
-	}, nil
 }
 
 // Send the successful but partial upload/delete, however ignore
@@ -1853,14 +1823,8 @@ func (er erasureObjects) TransitionObject(ctx context.Context, bucket, object st
 	eventName := event.ObjectTransitionComplete
 
 	storageDisks := er.getDisks()
-	// we now know the number of blocks this object needs for data and parity.
-	// writeQuorum is dataBlocks + 1
-	writeQuorum := fi.Erasure.DataBlocks
-	if fi.Erasure.DataBlocks == fi.Erasure.ParityBlocks {
-		writeQuorum++
-	}
 
-	if err = er.deleteObjectVersion(ctx, bucket, object, writeQuorum, fi, false); err != nil {
+	if err = er.deleteObjectVersion(ctx, bucket, object, fi, false); err != nil {
 		eventName = event.ObjectTransitionFailed
 	}
 

cmd/erasure-server-pool.go

@@ -380,19 +380,15 @@ func (z *erasureServerPools) getServerPoolsAvailableSpace(ctx context.Context, b
 	return serverPools
 }
 
-// poolObjInfo represents the state of an object per pool
+// PoolObjInfo represents the state of current object version per pool
-type poolObjInfo struct {
+type PoolObjInfo struct {
-	PoolIndex int
+	Index   int
 	ObjInfo ObjectInfo
 	Err     error
 }
 
-func (z *erasureServerPools) getPoolIdxExistingWithOpts(ctx context.Context, bucket, object string, opts ObjectOptions) (idx int, err error) {
+func (z *erasureServerPools) getPoolInfoExistingWithOpts(ctx context.Context, bucket, object string, opts ObjectOptions) (PoolObjInfo, error) {
-	if z.SinglePool() {
+	poolObjInfos := make([]PoolObjInfo, len(z.serverPools))
-		return 0, nil
-	}
-
-	poolObjInfos := make([]poolObjInfo, len(z.serverPools))
 	poolOpts := make([]ObjectOptions, len(z.serverPools))
 	for i := range z.serverPools {
 		poolOpts[i] = opts
@@ -404,8 +400,8 @@ func (z *erasureServerPools) getPoolIdxExistingWithOpts(ctx context.Context, buc
 		go func(i int, pool *erasureSets, opts ObjectOptions) {
 			defer wg.Done()
 			// remember the pool index, we may sort the slice original index might be lost.
-			pinfo := poolObjInfo{
+			pinfo := PoolObjInfo{
-				PoolIndex: i,
+				Index: i,
 			}
 			// do not remove this check as it can lead to inconsistencies
 			// for all callers of bucket replication.
@@ -429,19 +425,19 @@ func (z *erasureServerPools) getPoolIdxExistingWithOpts(ctx context.Context, buc
 	for _, pinfo := range poolObjInfos {
 		// skip all objects from suspended pools if asked by the
 		// caller.
-		if z.IsSuspended(pinfo.PoolIndex) && opts.SkipDecommissioned {
+		if z.IsSuspended(pinfo.Index) && opts.SkipDecommissioned {
 			continue
 		}
 
 		if pinfo.Err != nil && !isErrObjectNotFound(pinfo.Err) {
-			return -1, pinfo.Err
+			return pinfo, pinfo.Err
 		}
 
 		if isErrObjectNotFound(pinfo.Err) {
 			// No object exists or its a delete marker,
 			// check objInfo to confirm.
 			if pinfo.ObjInfo.DeleteMarker && pinfo.ObjInfo.Name != "" {
-				return pinfo.PoolIndex, nil
+				return pinfo, nil
 			}
 
 			// objInfo is not valid, truly the object doesn't
@@ -449,10 +445,18 @@ func (z *erasureServerPools) getPoolIdxExistingWithOpts(ctx context.Context, buc
 			continue
 		}
 
-		return pinfo.PoolIndex, nil
+		return pinfo, nil
 	}
 
-	return -1, toObjectErr(errFileNotFound, bucket, object)
+	return PoolObjInfo{}, toObjectErr(errFileNotFound, bucket, object)
+}
+
+func (z *erasureServerPools) getPoolIdxExistingWithOpts(ctx context.Context, bucket, object string, opts ObjectOptions) (idx int, err error) {
+	pinfo, err := z.getPoolInfoExistingWithOpts(ctx, bucket, object, opts)
+	if err != nil {
+		return -1, err
+	}
+	return pinfo.Index, nil
 }
 
 // getPoolIdxExistingNoLock returns the (first) found object pool index containing an object.
@@ -999,16 +1003,36 @@ func (z *erasureServerPools) DeleteObject(ctx context.Context, bucket string, ob
 	}
 
 	object = encodeDirObject(object)
-	if z.SinglePool() {
-		return z.serverPools[0].DeleteObject(ctx, bucket, object, opts)
-	}
 
-	idx, err := z.getPoolIdxExistingWithOpts(ctx, bucket, object, opts)
+	// Acquire a write lock before deleting the object.
+	lk := z.NewNSLock(bucket, object)
+	lkctx, err := lk.GetLock(ctx, globalDeleteOperationTimeout)
 	if err != nil {
+		return ObjectInfo{}, err
+	}
+	ctx = lkctx.Context()
+	defer lk.Unlock(lkctx.Cancel)
+
+	gopts := opts
+	gopts.NoLock = true
+	pinfo, err := z.getPoolInfoExistingWithOpts(ctx, bucket, object, gopts)
+	if err != nil {
+		switch err.(type) {
+		case InsufficientReadQuorum:
+			return objInfo, InsufficientWriteQuorum{}
+		}
 		return objInfo, err
 	}
 
-	return z.serverPools[idx].DeleteObject(ctx, bucket, object, opts)
+	// Delete marker already present we are not going to create new delete markers.
+	if pinfo.ObjInfo.DeleteMarker && opts.VersionID == "" {
+		pinfo.ObjInfo.Name = decodeDirObject(object)
+		return pinfo.ObjInfo, nil
+	}
+
+	objInfo, err = z.serverPools[pinfo.Index].DeleteObject(ctx, bucket, object, opts)
+	objInfo.Name = decodeDirObject(object)
+	return objInfo, err
 }
 
 func (z *erasureServerPools) DeleteObjects(ctx context.Context, bucket string, objects []ObjectToDelete, opts ObjectOptions) ([]DeletedObject, []error) {
@@ -1034,14 +1058,6 @@ func (z *erasureServerPools) DeleteObjects(ctx context.Context, bucket string, o
 	ctx = lkctx.Context()
 	defer multiDeleteLock.Unlock(lkctx.Cancel)
 
-	if z.SinglePool() {
-		deleteObjects, dErrs := z.serverPools[0].DeleteObjects(ctx, bucket, objects, opts)
-		for i := range deleteObjects {
-			deleteObjects[i].ObjectName = decodeDirObject(deleteObjects[i].ObjectName)
-		}
-		return deleteObjects, dErrs
-	}
-
 	// Fetch location of up to 10 objects concurrently.
 	poolObjIdxMap := map[int][]ObjectToDelete{}
 	origIndexMap := map[int][]int{}
@@ -1060,23 +1076,42 @@ func (z *erasureServerPools) DeleteObjects(ctx context.Context, bucket string, o
 		j := j
 		obj := obj
 		eg.Go(func() error {
-			idx, err := z.getPoolIdxExistingWithOpts(ctx, bucket, obj.ObjectName, ObjectOptions{
+			pinfo, err := z.getPoolInfoExistingWithOpts(ctx, bucket, obj.ObjectName, ObjectOptions{
 				NoLock: true,
 			})
 			if err != nil {
 				derrs[j] = err
+				dobjects[j] = DeletedObject{
+					ObjectName: obj.ObjectName,
+				}
 				return nil
 			}
+
+			// Delete marker already present we are not going to create new delete markers.
+			if pinfo.ObjInfo.DeleteMarker && obj.VersionID == "" {
+				dobjects[j] = DeletedObject{
+					DeleteMarker:          pinfo.ObjInfo.DeleteMarker,
+					DeleteMarkerVersionID: pinfo.ObjInfo.VersionID,
+					DeleteMarkerMTime:     DeleteMarkerMTime{pinfo.ObjInfo.ModTime},
+					ObjectName:            pinfo.ObjInfo.Name,
+				}
+				return nil
+			}
+
+			idx := pinfo.Index
+
 			mu.Lock()
+			defer mu.Unlock()
+
 			poolObjIdxMap[idx] = append(poolObjIdxMap[idx], obj)
 			origIndexMap[idx] = append(origIndexMap[idx], j)
-			mu.Unlock()
 			return nil
 		}, j)
 	}
 
 	eg.Wait() // wait to check all the pools.
 
+	if len(poolObjIdxMap) > 0 {
 		// Delete concurrently in all server pools.
 		var wg sync.WaitGroup
 		wg.Add(len(z.serverPools))
@@ -1100,6 +1135,7 @@ func (z *erasureServerPools) DeleteObjects(ctx context.Context, bucket string, o
 			}(idx, pool)
 		}
 		wg.Wait()
+	}
 
 	return dobjects, derrs
 }

cmd/erasure-single-drive.go

@@ -1223,7 +1223,7 @@ func (es *erasureSingle) putObject(ctx context.Context, bucket string, object st
 	return fi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
 }
 
-func (es *erasureSingle) deleteObjectVersion(ctx context.Context, bucket, object string, writeQuorum int, fi FileInfo, forceDelMarker bool) error {
+func (es *erasureSingle) deleteObjectVersion(ctx context.Context, bucket, object string, fi FileInfo, forceDelMarker bool) error {
 	return es.disk.DeleteVersion(ctx, bucket, object, fi, forceDelMarker)
 }
 
@@ -1447,7 +1447,7 @@ func (es *erasureSingle) DeleteObject(ctx context.Context, bucket, object string
 
 	versionFound := true
 	objInfo = ObjectInfo{VersionID: opts.VersionID} // version id needed in Delete API response.
-	goi, writeQuorum, gerr := es.getObjectInfoAndQuorum(ctx, bucket, object, opts)
+	goi, _, gerr := es.getObjectInfoAndQuorum(ctx, bucket, object, opts)
 	if gerr != nil && goi.Name == "" {
 		switch gerr.(type) {
 		case InsufficientReadQuorum:
@@ -1461,6 +1461,11 @@ func (es *erasureSingle) DeleteObject(ctx context.Context, bucket, object string
 		}
 	}
 
+	// Do not create new delete markers.
+	if goi.DeleteMarker && opts.VersionID == "" {
+		return goi, nil
+	}
+
 	if opts.Expiration.Expire {
 		action := evalActionFromLifecycle(ctx, *lc, rcfg, goi, false)
 		var isErr bool
@@ -1557,7 +1562,7 @@ func (es *erasureSingle) DeleteObject(ctx context.Context, bucket, object string
 			// delete marker. Add delete marker, since we don't have
 			// any version specified explicitly. Or if a particular
 			// version id needs to be replicated.
-			if err = es.deleteObjectVersion(ctx, bucket, object, writeQuorum, fi, opts.DeleteMarker); err != nil {
+			if err = es.deleteObjectVersion(ctx, bucket, object, fi, opts.DeleteMarker); err != nil {
 				return objInfo, toObjectErr(err, bucket, object)
 			}
 			return fi.ToObjectInfo(bucket, object, opts.Versioned || opts.VersionSuspended), nil
@@ -1576,7 +1581,7 @@ func (es *erasureSingle) DeleteObject(ctx context.Context, bucket, object string
 		ExpireRestored:   opts.Transition.ExpireRestored,
 	}
 	dfi.SetTierFreeVersionID(fvID)
-	if err = es.deleteObjectVersion(ctx, bucket, object, writeQuorum, dfi, opts.DeleteMarker); err != nil {
+	if err = es.deleteObjectVersion(ctx, bucket, object, dfi, opts.DeleteMarker); err != nil {
 		return objInfo, toObjectErr(err, bucket, object)
 	}
 
@@ -1813,14 +1818,7 @@ func (es *erasureSingle) TransitionObject(ctx context.Context, bucket, object st
 	fi.TransitionVersionID = string(rv)
 	eventName := event.ObjectTransitionComplete
 
-	// we now know the number of blocks this object needs for data and parity.
+	if err = es.deleteObjectVersion(ctx, bucket, object, fi, false); err != nil {
-	// writeQuorum is dataBlocks + 1
-	writeQuorum := fi.Erasure.DataBlocks
-	if fi.Erasure.DataBlocks == fi.Erasure.ParityBlocks {
-		writeQuorum++
-	}
-
-	if err = es.deleteObjectVersion(ctx, bucket, object, writeQuorum, fi, false); err != nil {
 		eventName = event.ObjectTransitionFailed
 	}
 

docs/bucket/replication/setup_2site_existing_replication.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -x
+
 trap 'catch $LINENO' ERR
 
 # shellcheck disable=SC2120
@@ -37,8 +39,10 @@ unset MINIO_KMS_KES_KEY_FILE
 unset MINIO_KMS_KES_ENDPOINT
 unset MINIO_KMS_KES_KEY_NAME
 
-wget -O mc https://dl.minio.io/client/mc/release/linux-amd64/mc \
+if [ ! -f ./mc ]; then
-    && chmod +x mc
+    wget --quiet -O mc https://dl.minio.io/client/mc/release/linux-amd64/mc && \
+        chmod +x mc
+fi
 
 minio server --address 127.0.0.1:9001 "http://127.0.0.1:9001/tmp/multisitea/data/disterasure/xl{1...4}" \
       "http://127.0.0.1:9002/tmp/multisitea/data/disterasure/xl{5...8}" >/tmp/sitea_1.log 2>&1 &
@@ -66,6 +70,9 @@ done
 ./mc mirror /tmp/data sitea/bucket/
 ./mc version enable sitea/bucket
 
+./mc cp /tmp/data/file_1.txt sitea/bucket/marker
+./mc rm sitea/bucket/marker
+
 ./mc mb siteb/bucket/
 ./mc version enable siteb/bucket/
 
@@ -83,11 +90,49 @@ sleep 1
 sleep 10s ## sleep for 10s idea is that we give 100ms per object.
 
 count=$(./mc replicate resync status sitea/bucket --remote-bucket "${remote_arn}" --json | jq .resyncInfo.target[].replicationCount)
-./mc ls --versions sitea/bucket
+
-./mc ls --versions siteb/bucket
+./mc ls -r --versions sitea/bucket > /tmp/sitea.txt
-if [ $count -ne 10 ]; then
+./mc ls -r --versions siteb/bucket > /tmp/siteb.txt
-    echo "resync not complete after 100s unexpected failure"
+
+out=$(diff -qpruN /tmp/sitea.txt /tmp/siteb.txt)
+ret=$?
+if [ $ret -ne 0 ]; then
+    echo "BUG: expected no missing entries after replication: $out"
+    exit 1
+fi
+
+if [ $count -ne 12 ]; then
+    echo "resync not complete after 10s unexpected failure"
     ./mc diff sitea/bucket siteb/bucket
+    exit 1
+fi
+
+./mc cp /tmp/data/file_1.txt sitea/bucket/marker_new
+./mc rm sitea/bucket/marker_new
+
+sleep 12s ## sleep for 12s idea is that we give 100ms per object.
+
+./mc ls -r --versions sitea/bucket > /tmp/sitea.txt
+./mc ls -r --versions siteb/bucket > /tmp/siteb.txt
+
+out=$(diff -qpruN /tmp/sitea.txt /tmp/siteb.txt)
+ret=$?
+if [ $ret -ne 0 ]; then
+    echo "BUG: expected no 'diff' after replication: $out"
+    exit 1
+fi
+
+./mc rm -r --force --versions sitea/bucket/marker
+sleep 14s ## sleep for 14s idea is that we give 100ms per object.
+
+./mc ls -r --versions sitea/bucket > /tmp/sitea.txt
+./mc ls -r --versions siteb/bucket > /tmp/siteb.txt
+
+out=$(diff -qpruN /tmp/sitea.txt /tmp/siteb.txt)
+ret=$?
+if [ $ret -ne 0 ]; then
+    echo "BUG: expected no 'diff' after replication: $out"
+    exit 1
 fi
 
 catch

docs/bucket/replication/setup_3site_replication.sh

@@ -1,5 +1,9 @@
 #!/usr/bin/env bash
 
+if [ -n "$TEST_DEBUG" ]; then
+    set -x
+fi
+
 trap 'catch $LINENO' ERR
 
 # shellcheck disable=SC2120