xl: Implement MRF healing (#8470)

cmd/admin-handlers_test.go

@@ -47,6 +47,10 @@ func prepareAdminXLTestBed() (*adminXLTestBed, error) {
 	// reset global variables to start afresh.
 	resetTestGlobals()
 
+	// Set globalIsXL to indicate that the setup uses an erasure
+	// code backend.
+	globalIsXL = true
+
 	// Initializing objectLayer for HealFormatHandler.
 	objLayer, xlDirs, xlErr := initTestXLObjLayer()
 	if xlErr != nil {
@@ -63,15 +67,6 @@ func prepareAdminXLTestBed() (*adminXLTestBed, error) {
 
 	globalEndpoints = mustGetZoneEndpoints(xlDirs...)
 
-	// Set globalIsXL to indicate that the setup uses an erasure
-	// code backend.
-	globalIsXL = true
-
-	// Init global heal state
-	if globalIsXL {
-		globalAllHealState = initHealState()
-	}
-
 	globalConfigSys = NewConfigSys()
 
 	globalIAMSys = NewIAMSys()

cmd/test-utils_test.go

@@ -459,15 +459,30 @@ func resetGlobalIsXL() {
 
 // reset global heal state
 func resetGlobalHealState() {
+	// Init global heal state
 	if globalAllHealState == nil {
-		return
+		globalAllHealState = initHealState()
+	} else {
+		globalAllHealState.Lock()
+		for _, v := range globalAllHealState.healSeqMap {
+			if !v.hasEnded() {
+				v.stop()
+			}
+		}
+		globalAllHealState.Unlock()
 	}
-	globalAllHealState.Lock()
-	defer globalAllHealState.Unlock()
-	for _, v := range globalAllHealState.healSeqMap {
-		if !v.hasEnded() {
-			v.stop()
+
+	// Init background heal state
+	if globalBackgroundHealState == nil {
+		globalBackgroundHealState = initHealState()
+	} else {
+		globalBackgroundHealState.Lock()
+		for _, v := range globalBackgroundHealState.healSeqMap {
+			if !v.hasEnded() {
+				v.stop()
+			}
 		}
+		globalBackgroundHealState.Unlock()
 	}
 }
 

cmd/xl-sets.go

@@ -56,6 +56,11 @@ func (s setsStorageAPI) Close() error {
 	return nil
 }
 
+// Information of a new disk connection
+type diskConnectInfo struct {
+	setIndex int
+}
+
 // xlSets implements ObjectLayer combining a static list of erasure coded
 // object sets. NOTE: There is no dynamic scaling allowed or intended in
 // current design.
@@ -80,6 +85,8 @@ type xlSets struct {
 	// Total number of sets and the number of disks per set.
 	setCount, drivesPerSet int
 
+	disksConnectEvent chan diskConnectInfo
+
 	// Done channel to control monitoring loop.
 	disksConnectDoneCh chan struct{}
 
@@ -88,6 +95,9 @@ type xlSets struct {
 
 	// Merge tree walk
 	pool *MergeWalkPool
+
+	mrfMU      sync.Mutex
+	mrfUploads map[string]int
 }
 
 // isConnected - checks if the endpoint is connected or not.
@@ -135,6 +145,8 @@ func connectEndpoint(endpoint Endpoint) (StorageAPI, *formatXLV3, error) {
 
 // findDiskIndex - returns the i,j'th position of the input `format` against the reference
 // format, after successful validation.
+//   - i'th position is the set index
+//   - j'th position is the disk index in the current set
 func findDiskIndex(refFormat, format *formatXLV3) (int, int, error) {
 	if err := formatXLV3Check(refFormat, format); err != nil {
 		return 0, 0, err
@@ -198,7 +210,7 @@ func (s *xlSets) connectDisks() {
 			printEndpointError(endpoint, err)
 			continue
 		}
-		i, j, err := findDiskIndex(s.format, format)
+		setIndex, diskIndex, err := findDiskIndex(s.format, format)
 		if err != nil {
 			// Close the internal connection to avoid connection leaks.
 			disk.Close()
@@ -207,8 +219,14 @@ func (s *xlSets) connectDisks() {
 		}
 		disk.SetDiskID(format.XL.This)
 		s.xlDisksMu.Lock()
-		s.xlDisks[i][j] = disk
+		s.xlDisks[setIndex][diskIndex] = disk
 		s.xlDisksMu.Unlock()
+
+		// Send a new disk connect event with a timeout
+		select {
+		case s.disksConnectEvent <- diskConnectInfo{setIndex: setIndex}:
+		case <-time.After(100 * time.Millisecond):
+		}
 	}
 }
 
@@ -216,6 +234,7 @@ func (s *xlSets) connectDisks() {
 // endpoints by reconnecting them and making sure to place them into right position in
 // the set topology, this monitoring happens at a given monitoring interval.
 func (s *xlSets) monitorAndConnectEndpoints(monitorInterval time.Duration) {
+
 	ticker := time.NewTicker(monitorInterval)
 	// Stop the timer.
 	defer ticker.Stop()
@@ -264,9 +283,11 @@ func newXLSets(endpoints Endpoints, format *formatXLV3, setCount int, drivesPerS
 		setCount:           setCount,
 		drivesPerSet:       drivesPerSet,
 		format:             format,
+		disksConnectEvent:  make(chan diskConnectInfo),
 		disksConnectDoneCh: make(chan struct{}),
 		distributionAlgo:   format.XL.DistributionAlgo,
 		pool:               NewMergeWalkPool(globalMergeLookupTimeout),
+		mrfUploads:         make(map[string]int),
 	}
 
 	mutex := newNSLock(globalIsDistXL)
@@ -281,10 +302,11 @@ func newXLSets(endpoints Endpoints, format *formatXLV3, setCount int, drivesPerS
 
 		// Initialize xl objects for a given set.
 		s.sets[i] = &xlObjects{
-			getDisks:   s.GetDisks(i),
-			getLockers: s.GetLockers(i),
-			nsMutex:    mutex,
-			bp:         bp,
+			getDisks:    s.GetDisks(i),
+			getLockers:  s.GetLockers(i),
+			nsMutex:     mutex,
+			bp:          bp,
+			mrfUploadCh: make(chan partialUpload, 10000),
 		}
 
 		go s.sets[i].cleanupStaleMultipartUploads(context.Background(),
@@ -304,6 +326,9 @@ func newXLSets(endpoints Endpoints, format *formatXLV3, setCount int, drivesPerS
 	// Start the disk monitoring and connect routine.
 	go s.monitorAndConnectEndpoints(defaultMonitorConnectEndpointInterval)
 
+	go s.maintainMRFList()
+	go s.healMRFRoutine()
+
 	return s, nil
 }
 
@@ -1665,3 +1690,72 @@ func (s *xlSets) IsReady(_ context.Context) bool {
 	// Disks are not ready
 	return false
 }
+
+// maintainMRFList gathers the list of successful partial uploads
+// from all underlying xl sets and puts them in a global map which
+// should not have more than 10000 entries.
+func (s *xlSets) maintainMRFList() {
+	var agg = make(chan partialUpload, 10000)
+	for i, xl := range s.sets {
+		go func(c <-chan partialUpload, setIndex int) {
+			for msg := range c {
+				msg.failedSet = setIndex
+				select {
+				case agg <- msg:
+				default:
+				}
+			}
+		}(xl.mrfUploadCh, i)
+	}
+
+	for fUpload := range agg {
+		s.mrfMU.Lock()
+		if len(s.mrfUploads) > 10000 {
+			s.mrfMU.Unlock()
+			continue
+		}
+		s.mrfUploads[pathJoin(fUpload.bucket, fUpload.object)] = fUpload.failedSet
+		s.mrfMU.Unlock()
+	}
+}
+
+// healMRFRoutine monitors new disks connection, sweep the MRF list
+// to find objects related to the new disk that needs to be healed.
+func (s *xlSets) healMRFRoutine() {
+	// Wait until background heal state is initialized
+	var bgSeq *healSequence
+	for {
+		var ok bool
+		bgSeq, ok = globalBackgroundHealState.getHealSequenceByToken(bgHealingUUID)
+		if ok {
+			break
+		}
+		time.Sleep(time.Second)
+	}
+
+	for e := range s.disksConnectEvent {
+		// Get the list of objects related the xl set
+		// to which the connected disk belongs.
+		var mrfUploads []string
+		s.mrfMU.Lock()
+		for k, v := range s.mrfUploads {
+			if v == e.setIndex {
+				mrfUploads = append(mrfUploads, k)
+			}
+		}
+		s.mrfMU.Unlock()
+
+		// Heal objects
+		for _, u := range mrfUploads {
+			// Send an object to be healed with a timeout
+			select {
+			case bgSeq.sourceCh <- u:
+			case <-time.After(100 * time.Millisecond):
+			}
+
+			s.mrfMU.Lock()
+			delete(s.mrfUploads, u)
+			s.mrfMU.Unlock()
+		}
+	}
+}

cmd/xl-v1-multipart.go

@@ -584,8 +584,10 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 
 	uploadIDPath := xl.getUploadIDDir(bucket, object, uploadID)
 
+	storageDisks := xl.getDisks()
+
 	// Read metadata associated with the object from all disks.
-	partsMetadata, errs := readAllXLMetadata(ctx, xl.getDisks(), minioMetaMultipartBucket, uploadIDPath)
+	partsMetadata, errs := readAllXLMetadata(ctx, storageDisks, minioMetaMultipartBucket, uploadIDPath)
 
 	// get Quorum for this object
 	_, writeQuorum, err := objectQuorumFromMeta(ctx, xl, partsMetadata, errs)
@@ -598,7 +600,7 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 		return oi, toObjectErr(reducedErr, bucket, object)
 	}
 
-	onlineDisks, modTime := listOnlineDisks(xl.getDisks(), partsMetadata, errs)
+	onlineDisks, modTime := listOnlineDisks(storageDisks, partsMetadata, errs)
 
 	// Calculate full object size.
 	var objectSize int64
@@ -743,10 +745,17 @@ func (xl xlObjects) CompleteMultipartUpload(ctx context.Context, bucket string,
 	}
 
 	// Rename the multipart object to final location.
-	if _, err = rename(ctx, onlineDisks, minioMetaMultipartBucket, uploadIDPath, bucket, object, true, writeQuorum, nil); err != nil {
+	if onlineDisks, err = rename(ctx, onlineDisks, minioMetaMultipartBucket, uploadIDPath, bucket, object, true, writeQuorum, nil); err != nil {
 		return oi, toObjectErr(err, bucket, object)
 	}
 
+	// Check if there is any offline disk and add it to the MRF list
+	for i := 0; i < len(onlineDisks); i++ {
+		if onlineDisks[i] == nil || storageDisks[i] == nil {
+			xl.addPartialUpload(bucket, object)
+		}
+	}
+
 	// Success, return object info.
 	return xlMeta.ToObjectInfo(bucket, object), nil
 }

cmd/xl-v1-object.go

@@ -626,7 +626,7 @@ func (xl xlObjects) putObject(ctx context.Context, bucket string, object string,
 		// NOTE: Do not use online disks slice here: the reason is that existing object should be purged
 		// regardless of `xl.json` status and rolled back in case of errors. Also allow renaming the
 		// existing object if it is not present in quorum disks so users can overwrite stale objects.
-		_, err = rename(ctx, xl.getDisks(), bucket, object, minioMetaTmpBucket, newUniqueID, true, writeQuorum, []error{errFileNotFound})
+		_, err = rename(ctx, storageDisks, bucket, object, minioMetaTmpBucket, newUniqueID, true, writeQuorum, []error{errFileNotFound})
 		if err != nil {
 			return ObjectInfo{}, toObjectErr(err, bucket, object)
 		}
@@ -646,11 +646,19 @@ func (xl xlObjects) putObject(ctx context.Context, bucket string, object string,
 	}
 
 	// Rename the successfully written temporary object to final location.
-	_, err = rename(ctx, onlineDisks, minioMetaTmpBucket, tempObj, bucket, object, true, writeQuorum, nil)
-	if err != nil {
+	if onlineDisks, err = rename(ctx, onlineDisks, minioMetaTmpBucket, tempObj, bucket, object, true, writeQuorum, nil); err != nil {
 		return ObjectInfo{}, toObjectErr(err, bucket, object)
 	}
 
+	// Whether a disk was initially or becomes offline
+	// during this upload, send it to the MRF list.
+	for i := 0; i < len(onlineDisks); i++ {
+		if onlineDisks[i] == nil || storageDisks[i] == nil {
+			xl.addPartialUpload(bucket, object)
+			break
+		}
+	}
+
 	// Object info is the same in all disks, so we can pick the first meta
 	// of the first disk
 	xlMeta = partsMetadata[0]
@@ -960,3 +968,12 @@ func (xl xlObjects) ListObjectsV2(ctx context.Context, bucket, prefix, continuat
 	}
 	return listObjectsV2Info, err
 }
+
+// Send the successul but partial upload, however ignore
+// if the channel is blocked by other items.
+func (xl xlObjects) addPartialUpload(bucket, key string) {
+	select {
+	case xl.mrfUploadCh <- partialUpload{bucket: bucket, object: key}:
+	default:
+	}
+}

cmd/xl-v1.go

@@ -39,6 +39,14 @@ const (
 // OfflineDisk represents an unavailable disk.
 var OfflineDisk StorageAPI // zero value is nil
 
+// partialUpload is a successful upload of an object
+// but not written in all disks (having quorum)
+type partialUpload struct {
+	bucket    string
+	object    string
+	failedSet int
+}
+
 // xlObjects - Implements XL object layer.
 type xlObjects struct {
 	// getDisks returns list of storageAPIs.
@@ -55,6 +63,8 @@ type xlObjects struct {
 
 	// TODO: ListObjects pool management, should be removed in future.
 	listPool *TreeWalkPool
+
+	mrfUploadCh chan partialUpload
 }
 
 // NewNSLock - initialize a new namespace RWLocker instance.