add support for tuning healing to make healing more aggressive (#11003)

supports `mc admin config set <alias> heal sleep=100ms` to
enable more aggressive healing under certain times.

also optimize some areas that were doing extra checks than
necessary when bitrotscan was enabled, avoid double sleeps
make healing more predictable.

fixes #10497

cmd/admin-heal-ops.go

@@ -657,6 +657,8 @@ func (h *healSequence) healSequenceStart(objAPI ObjectLayer) {
 }
 
 func (h *healSequence) queueHealTask(source healSource, healType madmin.HealItemType) error {
+	opts := globalHealConfig
+
 	// Send heal request
 	task := healTask{
 		bucket:     source.bucket,
@@ -667,7 +669,14 @@ func (h *healSequence) queueHealTask(source healSource, healType madmin.HealItem
 	}
 	if source.opts != nil {
 		task.opts = *source.opts
+	} else {
+		if opts.Bitrot {
+			task.opts.ScanMode = madmin.HealDeepScan
 		}
+	}
+
+	// Wait and proceed if there are active requests
+	waitForLowHTTPReq(opts.IOCount, opts.Sleep)
 
 	h.mutex.Lock()
 	h.scannedItemsMap[healType]++

cmd/background-heal-ops.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"time"
 
+	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/madmin"
 )
 
@@ -53,20 +54,28 @@ func (h *healRoutine) queueHealTask(task healTask) {
 	h.tasks <- task
 }
 
-func waitForLowHTTPReq(tolerance int32, maxWait time.Duration) {
-	const wait = 10 * time.Millisecond
-	waitCount := maxWait / wait
+func waitForLowHTTPReq(tolerance int, maxWait time.Duration) {
+	// At max 10 attempts to wait with 100 millisecond interval before proceeding
+	waitCount := 10
+	waitTick := 100 * time.Millisecond
 
 	// Bucket notification and http trace are not costly, it is okay to ignore them
 	// while counting the number of concurrent connections
-	tolerance += int32(globalHTTPListen.NumSubscribers() + globalHTTPTrace.NumSubscribers())
+	toleranceFn := func() int {
+		return tolerance + globalHTTPListen.NumSubscribers() + globalHTTPTrace.NumSubscribers()
+	}
 
 	if httpServer := newHTTPServerFn(); httpServer != nil {
 		// Any requests in progress, delay the heal.
-		for (httpServer.GetRequestCount() >= tolerance) &&
-			waitCount > 0 {
+		for httpServer.GetRequestCount() >= toleranceFn() {
+			time.Sleep(waitTick)
 			waitCount--
-			time.Sleep(wait)
+			if waitCount == 0 {
+				if intDataUpdateTracker.debug {
+					logger.Info("waitForLowHTTPReq: waited %d times, resuming", waitCount)
+				}
+				break
+			}
 		}
 	}
 }
@@ -80,9 +89,6 @@ func (h *healRoutine) run(ctx context.Context, objAPI ObjectLayer) {
 				break
 			}
 
-			// Wait and proceed if there are active requests
-			waitForLowHTTPReq(int32(globalEndpoints.NEndpoints()), time.Second)
-
 			var res madmin.HealResultItem
 			var err error
 			switch {

cmd/background-newdisks-heal-ops.go

@@ -124,8 +124,6 @@ wait:
 		case <-ctx.Done():
 			return
 		case <-time.After(defaultMonitorNewDiskInterval):
-			waitForLowHTTPReq(int32(globalEndpoints.NEndpoints()), time.Second)
-
 			var erasureSetInZoneDisksToHeal []map[int][]StorageAPI
 
 			healDisks := globalBackgroundHealState.getHealLocalDisks()

cmd/config/heal/heal.go

@@ -17,20 +17,32 @@
 package heal
 
 import (
-	"errors"
+	"fmt"
+	"strconv"
+	"time"
 
 	"github.com/minio/minio/cmd/config"
+	"github.com/minio/minio/pkg/env"
 )
 
 // Compression environment variables
 const (
 	Bitrot  = "bitrotscan"
+	Sleep   = "max_sleep"
+	IOCount = "max_io"
+
+	EnvBitrot  = "MINIO_HEAL_BITROTSCAN"
+	EnvSleep   = "MINIO_HEAL_MAX_SLEEP"
+	EnvIOCount = "MINIO_HEAL_MAX_IO"
 )
 
 // Config represents the heal settings.
 type Config struct {
 	// Bitrot will perform bitrot scan on local disk when checking objects.
 	Bitrot bool `json:"bitrotscan"`
+	// maximum sleep duration between objects to slow down heal operation.
+	Sleep   time.Duration `json:"sleep"`
+	IOCount int           `json:"iocount"`
 }
 
 var (
@@ -40,6 +52,14 @@ var (
 			Key:   Bitrot,
 			Value: config.EnableOff,
 		},
+		config.KV{
+			Key:   Sleep,
+			Value: "1s",
+		},
+		config.KV{
+			Key:   IOCount,
+			Value: "10",
+		},
 	}
 
 	// Help provides help for config values
@@ -50,6 +70,18 @@ var (
 			Optional:    true,
 			Type:        "on|off",
 		},
+		config.HelpKV{
+			Key:         Sleep,
+			Description: `maximum sleep duration between objects to slow down heal operation. eg. 2s`,
+			Optional:    true,
+			Type:        "duration",
+		},
+		config.HelpKV{
+			Key:         IOCount,
+			Description: `maximum IO requests allowed between objects to slow down heal operation. eg. 3`,
+			Optional:    true,
+			Type:        "int",
+		},
 	}
 )
 
@@ -58,10 +90,17 @@ func LookupConfig(kvs config.KVS) (cfg Config, err error) {
 	if err = config.CheckValidKeys(config.HealSubSys, kvs, DefaultKVS); err != nil {
 		return cfg, err
 	}
-	bitrot := kvs.Get(Bitrot)
-	if bitrot != config.EnableOn && bitrot != config.EnableOff {
-		return cfg, errors.New(Bitrot + ": must be 'on' or 'off'")
+	cfg.Bitrot, err = config.ParseBool(env.Get(EnvBitrot, kvs.Get(Bitrot)))
+	if err != nil {
+		return cfg, fmt.Errorf("'heal:bitrotscan' value invalid: %w", err)
+	}
+	cfg.Sleep, err = time.ParseDuration(env.Get(EnvSleep, kvs.Get(Sleep)))
+	if err != nil {
+		return cfg, fmt.Errorf("'heal:max_sleep' value invalid: %w", err)
+	}
+	cfg.IOCount, err = strconv.Atoi(env.Get(EnvIOCount, kvs.Get(IOCount)))
+	if err != nil {
+		return cfg, fmt.Errorf("'heal:max_io' value invalid: %w", err)
 	}
-	cfg.Bitrot = bitrot == config.EnableOn
 	return cfg, nil
 }

cmd/data-crawler.go

@@ -153,7 +153,7 @@ type folderScanner struct {
 
 // crawlDataFolder will crawl the basepath+cache.Info.Name and return an updated cache.
 // The returned cache will always be valid, but may not be updated from the existing.
-// Before each operation waitForLowActiveIO is called which can be used to temporarily halt the crawler.
+// Before each operation sleepDuration is called which can be used to temporarily halt the crawler.
 // If the supplied context is canceled the function will return at the first chance.
 func crawlDataFolder(ctx context.Context, basePath string, cache dataUsageCache, getSize getSizeFn) (dataUsageCache, error) {
 	t := UTCNow()
@@ -507,6 +507,7 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 
 			// Dynamic time delay.
 			t := UTCNow()
+
 			resolver.bucket = bucket
 
 			foundObjs := false
@@ -604,12 +605,6 @@ func (f *folderScanner) scanQueuedLevels(ctx context.Context, folders []cachedFo
 				// If we have quorum, found directories, but no objects, issue heal to delete the dangling.
 				objAPI.HealObjects(ctx, bucket, prefix, madmin.HealOpts{Recursive: true, Remove: true},
 					func(bucket, object, versionID string) error {
-						// Wait for each heal as per crawler frequency.
-						sleepDuration(time.Since(t), f.dataUsageCrawlMult)
-
-						defer func() {
-							t = UTCNow()
-						}()
 						return bgSeq.queueHealTask(healSource{
 							bucket:    bucket,
 							object:    object,

cmd/fs-v1.go

@@ -55,8 +55,6 @@ type FSObjects struct {
 
 	// The count of concurrent calls on FSObjects API
 	activeIOCount int64
-	// The active IO count ceiling for crawling to work
-	maxActiveIOCount int64
 
 	// Path to be exported over S3 API.
 	fsPath string
@@ -168,8 +166,6 @@ func NewFSObjectLayer(fsPath string) (ObjectLayer, error) {
 		listPool:      NewTreeWalkPool(globalLookupTimeout),
 		appendFileMap: make(map[string]*fsAppendFile),
 		diskMount:     mountinfo.IsLikelyMountPoint(fsPath),
-
-		maxActiveIOCount: 10,
 	}
 
 	// Once the filesystem has initialized hold the read lock for
@@ -230,12 +226,6 @@ func (fs *FSObjects) StorageInfo(ctx context.Context, _ bool) (StorageInfo, []er
 	return storageInfo, nil
 }
 
-func (fs *FSObjects) waitForLowActiveIO() {
-	for atomic.LoadInt64(&fs.activeIOCount) >= fs.maxActiveIOCount {
-		time.Sleep(lowActiveIOWaitTick)
-	}
-}
-
 // CrawlAndGetDataUsage returns data usage stats of the current FS deployment
 func (fs *FSObjects) CrawlAndGetDataUsage(ctx context.Context, bf *bloomFilter, updates chan<- DataUsageInfo) error {
 	// Load bucket totals

cmd/global-heal.go

@@ -186,7 +186,10 @@ func deepHealObject(bucket, object, versionID string) {
 			bucket:    bucket,
 			object:    object,
 			versionID: versionID,
-			opts:      &madmin.HealOpts{ScanMode: madmin.HealDeepScan},
+			opts: &madmin.HealOpts{
+				Remove:   true, // if found dangling purge it.
+				ScanMode: madmin.HealDeepScan,
+			},
 		}
 	}
 }

cmd/http/server.go

@@ -57,8 +57,8 @@ type Server struct {
 }
 
 // GetRequestCount - returns number of request in progress.
-func (srv *Server) GetRequestCount() int32 {
-	return atomic.LoadInt32(&srv.requestCount)
+func (srv *Server) GetRequestCount() int {
+	return int(atomic.LoadInt32(&srv.requestCount))
 }
 
 // Start - start HTTP server

cmd/xl-storage.go

@@ -63,12 +63,6 @@ const (
 	// Size of each buffer.
 	readAheadBufSize = 1 << 20
 
-	// Wait interval to check if active IO count is low
-	// to proceed crawling to compute data usage.
-	// Wait up to lowActiveIOWaitMaxN times.
-	lowActiveIOWaitTick = 100 * time.Millisecond
-	lowActiveIOWaitMaxN = 10
-
 	// XL metadata file carries per object metadata.
 	xlStorageFormatFile = "xl.meta"
 )
@@ -90,7 +84,6 @@ func isValidVolname(volname string) bool {
 
 // xlStorage - implements StorageAPI interface.
 type xlStorage struct {
-	maxActiveIOCount int32
 	activeIOCount int32
 
 	diskPath string
@@ -262,11 +255,6 @@ func newXLStorage(ep Endpoint) (*xlStorage, error) {
 			},
 		},
 		globalSync: env.Get(config.EnvFSOSync, config.EnableOff) == config.EnableOn,
-		// Allow disk usage crawler to run with up to 2 concurrent
-		// I/O ops, if and when activeIOCount reaches this
-		// value disk usage routine suspends the crawler
-		// and waits until activeIOCount reaches below this threshold.
-		maxActiveIOCount: 3,
 		ctx:        GlobalContext,
 		rootDisk:   rootDisk,
 	}
@@ -336,20 +324,6 @@ func (s *xlStorage) Healing() bool {
 	return err == nil
 }
 
-func (s *xlStorage) waitForLowActiveIO() {
-	max := lowActiveIOWaitMaxN
-	for atomic.LoadInt32(&s.activeIOCount) >= s.maxActiveIOCount {
-		time.Sleep(lowActiveIOWaitTick)
-		max--
-		if max == 0 {
-			if intDataUpdateTracker.debug {
-				logger.Info("waitForLowActiveIO: waited %d times, resuming", lowActiveIOWaitMaxN)
-			}
-			break
-		}
-	}
-}
-
 func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCache) (dataUsageCache, error) {
 	// Check if the current bucket has a configured lifecycle policy
 	lc, err := globalLifecycleSys.Get(cache.Info.Name)
@@ -402,10 +376,7 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 			if !version.Deleted {
 				// Bitrot check local data
 				if size > 0 && item.heal && opts.Bitrot {
-					s.waitForLowActiveIO()
-					err := s.VerifyFile(ctx, item.bucket, item.objectPath(), version)
-					switch err {
-					case errFileCorrupt:
+					// HealObject verifies bitrot requirement internally
 					res, err := objAPI.HealObject(ctx, item.bucket, item.objectPath(), oi.VersionID, madmin.HealOpts{
 						Remove:   healDeleteDangling,
 						ScanMode: madmin.HealDeepScan,
@@ -418,9 +389,6 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 					} else {
 						size = res.ObjectSize
 					}
-					default:
-						// VerifyFile already logs errors
-					}
 				}
 				totalSize += size
 			}