Parallelize initialization of storageDisks (#8288)

cmd/format-xl.go

@@ -677,34 +677,22 @@ func closeStorageDisks(storageDisks []StorageAPI) {
 	}
 }
 
-// Initialize storage disks based on input arguments.
+// Initialize storage disks for each endpoint.
-func initStorageDisks(endpoints EndpointList) ([]StorageAPI, error) {
+// Errors are returned for each endpoint with matching index.
+func initStorageDisksWithErrors(endpoints EndpointList) ([]StorageAPI, []error) {
 	// Bootstrap disks.
 	storageDisks := make([]StorageAPI, len(endpoints))
+	errs := make([]error, len(endpoints))
+	var wg sync.WaitGroup
 	for index, endpoint := range endpoints {
-		storage, err := newStorageAPI(endpoint)
+		wg.Add(1)
-		if err != nil && err != errDiskNotFound {
+		go func(index int, endpoint Endpoint) {
-			return nil, err
+			defer wg.Done()
-		}
+			storageDisks[index], errs[index] = newStorageAPI(endpoint)
-		storageDisks[index] = storage
+		}(index, endpoint)
-	}
-	return storageDisks, nil
-}
-
-// Runs through the faulty disks and record their errors.
-func initDisksWithErrors(endpoints EndpointList) ([]StorageAPI, []error) {
-	storageDisks := make([]StorageAPI, len(endpoints))
-	var dErrs = make([]error, len(storageDisks))
-	for index, endpoint := range endpoints {
-		storage, err := newStorageAPI(endpoint)
-		if err != nil {
-			logger.LogIf(context.Background(), err)
-			dErrs[index] = err
-			continue
-		}
-		storageDisks[index] = storage
 	}
-	return storageDisks, dErrs
+	wg.Wait()
+	return storageDisks, errs
 }
 
 // formatXLV3ThisEmpty - find out if '.This' field is empty

cmd/format-xl_test.go

@@ -85,9 +85,11 @@ func TestFixFormatV3(t *testing.T) {
 	}
 	endpoints := mustGetNewEndpointList(xlDirs...)
 
-	storageDisks, err := initStorageDisks(endpoints)
+	storageDisks, errs := initStorageDisksWithErrors(endpoints)
-	if err != nil {
+	for _, err := range errs {
-		t.Fatal(err)
+		if err != nil && err != errDiskNotFound {
+			t.Fatal(err)
+		}
 	}
 
 	format := newFormatXLV3(1, 8)
@@ -566,3 +568,36 @@ func TestNewFormatSets(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkInitStorageDisks256(b *testing.B) {
+	benchmarkInitStorageDisksN(b, 256)
+}
+
+func BenchmarkInitStorageDisks1024(b *testing.B) {
+	benchmarkInitStorageDisksN(b, 1024)
+}
+
+func BenchmarkInitStorageDisks2048(b *testing.B) {
+	benchmarkInitStorageDisksN(b, 2048)
+}
+
+func BenchmarkInitStorageDisksMax(b *testing.B) {
+	benchmarkInitStorageDisksN(b, 32*204)
+}
+
+func benchmarkInitStorageDisksN(b *testing.B, nDisks int) {
+	b.ResetTimer()
+	b.ReportAllocs()
+
+	fsDirs, err := getRandomDisks(nDisks)
+	if err != nil {
+		b.Fatal(err)
+	}
+	endpoints := mustGetNewEndpointList(fsDirs...)
+	b.RunParallel(func(pb *testing.PB) {
+		endpoints := endpoints
+		for pb.Next() {
+			initStorageDisksWithErrors(endpoints)
+		}
+	})
+}

cmd/prepare-storage.go

@@ -172,11 +172,13 @@ var errXLV3ThisEmpty = fmt.Errorf("XL format version 3 has This field empty")
 // time. additionally make sure to close all the disks used in this attempt.
 func connectLoadInitFormats(retryCount int, firstDisk bool, endpoints EndpointList, setCount, drivesPerSet int) (*formatXLV3, error) {
 	// Initialize all storage disks
-	storageDisks, err := initStorageDisks(endpoints)
+	storageDisks, errs := initStorageDisksWithErrors(endpoints)
-	if err != nil {
-		return nil, err
-	}
 	defer closeStorageDisks(storageDisks)
+	for i, err := range errs {
+		if err != nil && err != errDiskNotFound {
+			return nil, fmt.Errorf("Disk %s: %w", endpoints[i], err)
+		}
+	}
 
 	// Attempt to load all `format.json` from all disks.
 	formatConfigs, sErrs := loadFormatXLAll(storageDisks)
@@ -203,7 +205,7 @@ func connectLoadInitFormats(retryCount int, firstDisk bool, endpoints EndpointLi
 	// most part unless one of the formats is not consistent
 	// with expected XL format. For example if a user is
 	// trying to pool FS backend into an XL set.
-	if err = checkFormatXLValues(formatConfigs); err != nil {
+	if err := checkFormatXLValues(formatConfigs); err != nil {
 		return nil, err
 	}
 
@@ -236,7 +238,7 @@ func connectLoadInitFormats(retryCount int, firstDisk bool, endpoints EndpointLi
 	// This migration failed to capture '.This' field properly which indicates
 	// the disk UUID association. Below function is called to handle and fix
 	// this regression, for more info refer https://github.com/minio/minio/issues/5667
-	if err = fixFormatXLV3(storageDisks, endpoints, formatConfigs); err != nil {
+	if err := fixFormatXLV3(storageDisks, endpoints, formatConfigs); err != nil {
 		return nil, err
 	}
 

cmd/test-utils_test.go

@@ -1615,9 +1615,11 @@ func newTestObjectLayer(endpoints EndpointList) (newObject ObjectLayer, err erro
 		return nil, err
 	}
 
-	storageDisks, err := initStorageDisks(endpoints)
+	storageDisks, errs := initStorageDisksWithErrors(endpoints)
-	if err != nil {
+	for _, err = range errs {
-		return nil, err
+		if err != nil && err != errDiskNotFound {
+			return nil, err
+		}
 	}
 
 	// Initialize list pool.

cmd/xl-sets.go

@@ -339,7 +339,7 @@ func (s *xlSets) StorageInfo(ctx context.Context) StorageInfo {
 		storageInfo.Backend.Sets[i] = make([]madmin.DriveInfo, s.drivesPerSet)
 	}
 
-	storageDisks, dErrs := initDisksWithErrors(s.endpoints)
+	storageDisks, dErrs := initStorageDisksWithErrors(s.endpoints)
 	defer closeStorageDisks(storageDisks)
 
 	formats, sErrs := loadFormatXLAll(storageDisks)
@@ -1324,9 +1324,11 @@ func (s *xlSets) ReloadFormat(ctx context.Context, dryRun bool) (err error) {
 	}
 	defer formatLock.RUnlock()
 
-	storageDisks, err := initStorageDisks(s.endpoints)
+	storageDisks, errs := initStorageDisksWithErrors(s.endpoints)
-	if err != nil {
+	for i, err := range errs {
-		return err
+		if err != nil && err != errDiskNotFound {
+			return fmt.Errorf("Disk %s: %w", s.endpoints[i], err)
+		}
 	}
 	defer func(storageDisks []StorageAPI) {
 		if err != nil {
@@ -1445,9 +1447,11 @@ func (s *xlSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.HealRe
 	}
 	defer formatLock.Unlock()
 
-	storageDisks, err := initStorageDisks(s.endpoints)
+	storageDisks, errs := initStorageDisksWithErrors(s.endpoints)
-	if err != nil {
+	for i, derr := range errs {
-		return madmin.HealResultItem{}, err
+		if derr != nil && derr != errDiskNotFound {
+			return madmin.HealResultItem{}, fmt.Errorf("Disk %s: %w", s.endpoints[i], derr)
+		}
 	}
 
 	defer func(storageDisks []StorageAPI) {