fix: background disk heal, to reload format consistently (#10502)

It was observed in VMware vsphere environment during a
pod replacement, `mc admin info` might report incorrect
offline nodes for the replaced drive. This issue eventually
goes away but requires quite a lot of time for all servers
to be in sync.

This PR fixes this behavior properly.

cmd/background-heal-ops.go

@@ -21,7 +21,6 @@ import (
 	"path"
 	"time"
 
-	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/madmin"
 )
 
@@ -129,24 +128,5 @@ func healDiskFormat(ctx context.Context, objAPI ObjectLayer, opts madmin.HealOpt
 		return madmin.HealResultItem{}, err
 	}
 
-	// Healing succeeded notify the peers to reload format and re-initialize disks.
-	// We will not notify peers if healing is not required.
-	if err == nil {
-		// Notify servers in background and retry if needed.
-		go func() {
-		retry:
-			for _, nerr := range globalNotificationSys.ReloadFormat(opts.DryRun) {
-				if nerr.Err != nil {
-					if nerr.Err.Error() == errServerNotInitialized.Error() {
-						time.Sleep(time.Second)
-						goto retry
-					}
-					logger.GetReqInfo(ctx).SetTags("peerAddress", nerr.Host.String())
-					logger.LogIf(ctx, nerr.Err)
-				}
-			}
-		}()
-	}
-
 	return res, nil
 }

cmd/background-newdisks-heal-ops.go

@@ -106,23 +106,26 @@ func monitorLocalDisksAndHeal(ctx context.Context, z *erasureZones, bgSeq *healS
 		case <-time.After(defaultMonitorNewDiskInterval):
 			waitForLowHTTPReq(int32(globalEndpoints.NEndpoints()), time.Second)
 
-			var erasureSetInZoneEndpointToHeal = make([]map[int]Endpoint, len(z.zones))
-			for i := range z.zones {
-				erasureSetInZoneEndpointToHeal[i] = map[int]Endpoint{}
-			}
-
+			var erasureSetInZoneEndpointToHeal []map[int]Endpoints
 			healDisks := globalBackgroundHealState.getHealLocalDisks()
-			// heal only if new disks found.
-			for _, endpoint := range healDisks {
-				logger.Info(fmt.Sprintf("Found drives to heal %d, proceeding to heal content...",
-					len(healDisks)))
-
+			if len(healDisks) > 0 {
 				// Reformat disks
 				bgSeq.sourceCh <- healSource{bucket: SlashSeparator}
 
 				// Ensure that reformatting disks is finished
 				bgSeq.sourceCh <- healSource{bucket: nopHeal}
 
+				logger.Info(fmt.Sprintf("Found drives to heal %d, proceeding to heal content...",
+					len(healDisks)))
+
+				erasureSetInZoneEndpointToHeal = make([]map[int]Endpoints, len(z.zones))
+				for i := range z.zones {
+					erasureSetInZoneEndpointToHeal[i] = map[int]Endpoints{}
+				}
+			}
+
+			// heal only if new disks found.
+			for _, endpoint := range healDisks {
 				// Load the new format of this passed endpoint
 				_, format, err := connectEndpoint(endpoint)
 				if err != nil {
@@ -142,20 +145,22 @@ func monitorLocalDisksAndHeal(ctx context.Context, z *erasureZones, bgSeq *healS
 					continue
 				}
 
-				erasureSetInZoneEndpointToHeal[zoneIdx][setIndex] = endpoint
+				erasureSetInZoneEndpointToHeal[zoneIdx][setIndex] = append(erasureSetInZoneEndpointToHeal[zoneIdx][setIndex], endpoint)
 			}
 
 			for i, setMap := range erasureSetInZoneEndpointToHeal {
-				for setIndex, endpoint := range setMap {
-					logger.Info("Healing disk '%s' on %s zone", endpoint, humanize.Ordinal(i+1))
+				for setIndex, endpoints := range setMap {
+					for _, ep := range endpoints {
+						logger.Info("Healing disk '%s' on %s zone", ep, humanize.Ordinal(i+1))
 
-					if err := healErasureSet(ctx, setIndex, z.zones[i].sets[setIndex], z.zones[i].setDriveCount); err != nil {
-						logger.LogIf(ctx, err)
-						continue
+						if err := healErasureSet(ctx, setIndex, z.zones[i].sets[setIndex], z.zones[i].setDriveCount); err != nil {
+							logger.LogIf(ctx, err)
+							continue
+						}
+
+						// Only upon success pop the healed disk.
+						globalBackgroundHealState.popHealLocalDisks(ep)
 					}
-
-					// Only upon success pop the healed disk.
-					globalBackgroundHealState.popHealLocalDisks(endpoint)
 				}
 			}
 		}

cmd/erasure-sets.go

@@ -80,9 +80,6 @@ type erasureSets struct {
 
 	disksConnectEvent chan diskConnectInfo
 
-	// Done channel to control monitoring loop.
-	disksConnectDoneCh chan struct{}
-
 	// Distribution algorithm of choice.
 	distributionAlgo string
 	deploymentID     [16]byte
@@ -115,7 +112,7 @@ func (s *erasureSets) getDiskMap() map[string]StorageAPI {
 	for i := 0; i < s.setCount; i++ {
 		for j := 0; j < s.setDriveCount; j++ {
 			disk := s.erasureDisks[i][j]
-			if disk == nil {
+			if disk == OfflineDisk {
 				continue
 			}
 			if !disk.IsOnline() {
@@ -211,14 +208,16 @@ func (s *erasureSets) connectDisks() {
 			disk, format, err := connectEndpoint(endpoint)
 			if err != nil {
 				if endpoint.IsLocal && errors.Is(err, errUnformattedDisk) {
-					logger.Info(fmt.Sprintf("Found unformatted drive %s, attempting to heal...", endpoint))
 					globalBackgroundHealState.pushHealLocalDisks(endpoint)
+					logger.Info(fmt.Sprintf("Found unformatted drive %s, attempting to heal...", endpoint))
 				} else {
 					printEndpointError(endpoint, err, true)
 				}
 				return
 			}
+			s.erasureDisksMu.RLock()
 			setIndex, diskIndex, err := findDiskIndex(s.format, format)
+			s.erasureDisksMu.RUnlock()
 			if err != nil {
 				if endpoint.IsLocal {
 					globalBackgroundHealState.pushHealLocalDisks(endpoint)
@@ -256,8 +255,6 @@ func (s *erasureSets) monitorAndConnectEndpoints(ctx context.Context, monitorInt
 		select {
 		case <-ctx.Done():
 			return
-		case <-s.disksConnectDoneCh:
-			return
 		case <-time.After(monitorInterval):
 			s.connectDisks()
 		}
@@ -318,7 +315,6 @@ func newErasureSets(ctx context.Context, endpoints Endpoints, storageDisks []Sto
 		listTolerancePerSet: setDriveCount / 2,
 		format:              format,
 		disksConnectEvent:   make(chan diskConnectInfo),
-		disksConnectDoneCh:  make(chan struct{}),
 		distributionAlgo:    format.Erasure.DistributionAlgo,
 		deploymentID:        uuid.MustParse(format.ID),
 		pool:                NewMergeWalkPool(globalMergeLookupTimeout),
@@ -1191,16 +1187,12 @@ func (s *erasureSets) ReloadFormat(ctx context.Context, dryRun bool) (err error)
 		return err
 	}
 
-	// kill the monitoring loop such that we stop writing
-	// to indicate that we will re-initialize everything
-	// with new format.
-	s.disksConnectDoneCh <- struct{}{}
+	s.erasureDisksMu.Lock()
 
 	// Replace with new reference format.
 	s.format = refFormat
 
 	// Close all existing disks and reconnect all the disks.
-	s.erasureDisksMu.Lock()
 	for _, disk := range storageDisks {
 		if disk == nil {
 			continue
@@ -1223,10 +1215,8 @@ func (s *erasureSets) ReloadFormat(ctx context.Context, dryRun bool) (err error)
 		s.endpointStrings[m*s.setDriveCount+n] = disk.String()
 		s.erasureDisks[m][n] = disk
 	}
-	s.erasureDisksMu.Unlock()
 
-	// Restart monitoring loop to monitor reformatted disks again.
-	go s.monitorAndConnectEndpoints(GlobalContext, defaultMonitorConnectEndpointInterval)
+	s.erasureDisksMu.Unlock()
 
 	return nil
 }
@@ -1400,16 +1390,12 @@ func (s *erasureSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.H
 			return madmin.HealResultItem{}, err
 		}
 
-		// kill the monitoring loop such that we stop writing
-		// to indicate that we will re-initialize everything
-		// with new format.
-		s.disksConnectDoneCh <- struct{}{}
+		s.erasureDisksMu.Lock()
 
 		// Replace with new reference format.
 		s.format = refFormat
 
 		// Disconnect/relinquish all existing disks, lockers and reconnect the disks, lockers.
-		s.erasureDisksMu.Lock()
 		for _, disk := range storageDisks {
 			if disk == nil {
 				continue
@@ -1432,10 +1418,8 @@ func (s *erasureSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.H
 			s.endpointStrings[m*s.setDriveCount+n] = disk.String()
 			s.erasureDisks[m][n] = disk
 		}
-		s.erasureDisksMu.Unlock()
 
-		// Restart our monitoring loop to start monitoring newly formatted disks.
-		go s.monitorAndConnectEndpoints(GlobalContext, defaultMonitorConnectEndpointInterval)
+		s.erasureDisksMu.Unlock()
 	}
 
 	return res, nil

cmd/erasure-zones.go

@@ -18,6 +18,7 @@ package cmd
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
@@ -1608,13 +1609,8 @@ func (z *erasureZones) ListBuckets(ctx context.Context) (buckets []BucketInfo, e
 }
 
 func (z *erasureZones) ReloadFormat(ctx context.Context, dryRun bool) error {
-	// Acquire lock on format.json
-	formatLock := z.NewNSLock(ctx, minioMetaBucket, formatConfigFile)
-	if err := formatLock.GetRLock(globalOperationTimeout); err != nil {
-		return err
-	}
-	defer formatLock.RUnlock()
-
+	// No locks needed since reload happens in HealFormat under
+	// write lock across all nodes.
 	for _, zone := range z.zones {
 		if err := zone.ReloadFormat(ctx, dryRun); err != nil {
 			return err
@@ -1639,13 +1635,13 @@ func (z *erasureZones) HealFormat(ctx context.Context, dryRun bool) (madmin.Heal
 	var countNoHeal int
 	for _, zone := range z.zones {
 		result, err := zone.HealFormat(ctx, dryRun)
-		if err != nil && err != errNoHealRequired {
+		if err != nil && !errors.Is(err, errNoHealRequired) {
 			logger.LogIf(ctx, err)
 			continue
 		}
 		// Count errNoHealRequired across all zones,
 		// to return appropriate error to the caller
-		if err == errNoHealRequired {
+		if errors.Is(err, errNoHealRequired) {
 			countNoHeal++
 		}
 		r.DiskCount += result.DiskCount
@@ -1653,10 +1649,21 @@ func (z *erasureZones) HealFormat(ctx context.Context, dryRun bool) (madmin.Heal
 		r.Before.Drives = append(r.Before.Drives, result.Before.Drives...)
 		r.After.Drives = append(r.After.Drives, result.After.Drives...)
 	}
+
+	// Healing succeeded notify the peers to reload format and re-initialize disks.
+	// We will not notify peers if healing is not required.
+	for _, nerr := range globalNotificationSys.ReloadFormat(dryRun) {
+		if nerr.Err != nil {
+			logger.GetReqInfo(ctx).SetTags("peerAddress", nerr.Host.String())
+			logger.LogIf(ctx, nerr.Err)
+		}
+	}
+
 	// No heal returned by all zones, return errNoHealRequired
 	if countNoHeal == len(z.zones) {
 		return r, errNoHealRequired
 	}
+
 	return r, nil
 }
 

cmd/erasure.go

@@ -140,6 +140,7 @@ func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []madmin.Di
 		index := index
 		g.Go(func() error {
 			if disks[index] == OfflineDisk {
+				logger.LogIf(GlobalContext, fmt.Errorf("%s: %s", errDiskNotFound, endpoints[index]))
 				disksInfo[index] = madmin.Disk{
 					State:    diskErrToDriveState(errDiskNotFound),
 					Endpoint: endpoints[index],
@@ -149,11 +150,9 @@ func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []madmin.Di
 			}
 			info, err := disks[index].DiskInfo(context.TODO())
 			if err != nil {
-				if !IsErr(err, baseErrs...) {
-					reqInfo := (&logger.ReqInfo{}).AppendTags("disk", disks[index].String())
-					ctx := logger.SetReqInfo(GlobalContext, reqInfo)
-					logger.LogIf(ctx, err)
-				}
+				reqInfo := (&logger.ReqInfo{}).AppendTags("disk", disks[index].String())
+				ctx := logger.SetReqInfo(GlobalContext, reqInfo)
+				logger.LogIf(ctx, err)
 				disksInfo[index] = madmin.Disk{
 					State:    diskErrToDriveState(err),
 					Endpoint: endpoints[index],

cmd/peer-rest-client.go

@@ -481,11 +481,7 @@ func (client *peerRESTClient) DeleteBucketMetadata(bucket string) error {
 // ReloadFormat - reload format on the peer node.
 func (client *peerRESTClient) ReloadFormat(dryRun bool) error {
 	values := make(url.Values)
-	if dryRun {
-		values.Set(peerRESTDryRun, "true")
-	} else {
-		values.Set(peerRESTDryRun, "false")
-	}
+	values.Set(peerRESTDryRun, strconv.FormatBool(dryRun))
 
 	respBody, err := client.call(peerRESTMethodReloadFormat, values, nil, -1)
 	if err != nil {

cmd/rest/client.go

@@ -103,9 +103,6 @@ func (c *Client) Call(ctx context.Context, method string, values url.Values, bod
 	}
 	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.url.String()+method+querySep+values.Encode(), body)
 	if err != nil {
-		if xnet.IsNetworkOrHostDown(err) {
-			c.MarkOffline()
-		}
 		return nil, &NetworkError{err}
 	}
 	req.Header.Set("Authorization", "Bearer "+c.newAuthToken(req.URL.Query().Encode()))
@@ -173,7 +170,6 @@ func NewClient(url *url.URL, newCustomTransport func() *http.Transport, newAuthT
 		url:                 url,
 		newAuthToken:        newAuthToken,
 		connected:           online,
-
 		MaxErrResponseSize:  4096,
 		HealthCheckInterval: 200 * time.Millisecond,
 		HealthCheckTimeout:  time.Second,
@@ -191,21 +187,18 @@ func (c *Client) MarkOffline() {
 	// Start goroutine that will attempt to reconnect.
 	// If server is already trying to reconnect this will have no effect.
 	if c.HealthCheckFn != nil && atomic.CompareAndSwapInt32(&c.connected, online, offline) {
-		if c.httpIdleConnsCloser != nil {
-			c.httpIdleConnsCloser()
-		}
-		go func() {
+		go func(healthFunc func() bool) {
 			ticker := time.NewTicker(c.HealthCheckInterval)
 			defer ticker.Stop()
 			for range ticker.C {
-				if status := atomic.LoadInt32(&c.connected); status == closed {
+				if atomic.LoadInt32(&c.connected) == closed {
 					return
 				}
-				if c.HealthCheckFn() {
+				if healthFunc() {
 					atomic.CompareAndSwapInt32(&c.connected, offline, online)
 					return
 				}
 			}
-		}()
+		}(c.HealthCheckFn)
 	}
 }

cmd/storage-rest-server.go

@@ -106,6 +106,7 @@ func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool
 		s.writeErrorResponse(w, err)
 		return false
 	}
+
 	diskID := r.URL.Query().Get(storageRESTDiskID)
 	if diskID == "" {
 		// Request sent empty disk-id, we allow the request
@@ -113,6 +114,7 @@ func (s *storageRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool
 		// or create format.json
 		return true
 	}
+
 	storedDiskID, err := s.storage.GetDiskID()
 	if err != nil {
 		s.writeErrorResponse(w, err)