snap_restore: added retry for recovery

br/pkg/restore/data.go

@@ -27,6 +27,75 @@
 	"google.golang.org/grpc/backoff"
 )
 
+type RecoveryStage int
+
+const (
+	StageUnknown RecoveryStage = iota
+	StageCollectingMeta
+	StageMakingRecoveryPlan
+	StageResetPDAllocateID
+	StageRecovering
+	StageFlashback
+)
+
+func (s RecoveryStage) String() string {
+	switch s {
+	case StageCollectingMeta:
+		return "collecting meta"
+	case StageMakingRecoveryPlan:
+		return "making recovery plan"
+	case StageResetPDAllocateID:
+		return "resetting PD allocate ID"
+	case StageRecovering:
+		return "recovering"
+	case StageFlashback:
+		return "flashback"
+	default:
+		return "unknown"
+	}
+}
+
+type recoveryError struct {
+	error
+	atStage RecoveryStage
+}
+
+func FailedAt(err error) RecoveryStage {
+	if rerr, ok := err.(recoveryError); ok {
+		return rerr.atStage
+	}
+	return StageUnknown
+}
+
+type recoveryBackoffer struct {
+	state utils.RetryState
+}
+
+func newRecoveryBackoffer() *recoveryBackoffer {
+	return &recoveryBackoffer{
+		state: utils.InitialRetryState(16, 0, 0),
+	}
+}
+
+func (bo *recoveryBackoffer) NextBackoff(err error) time.Duration {
+	s := FailedAt(err)
+	switch s {
+	case StageCollectingMeta, StageMakingRecoveryPlan, StageResetPDAllocateID, StageRecovering:
+		log.Info("Recovery data retrying.", zap.Error(err), zap.Stringer("stage", s))
+		return bo.state.ExponentialBackoff()
+	case StageFlashback:
+		log.Info("Giving up retry for flashback stage.", zap.Error(err), zap.Stringer("stage", s))
+		bo.state.GiveUp()
+		return 0
+	}
+	log.Warn("unknown stage of backing off.", zap.Int("val", int(s)))
+	return bo.state.ExponentialBackoff()
+}
+
+func (bo *recoveryBackoffer) Attempt() int {
+	return bo.state.Attempt()
+}
+
 // RecoverData recover the tikv cluster
 // 1. read all meta data from tikvs
 // 2. make recovery plan and then recovery max allocate ID firstly
@@ -35,39 +104,50 @@
 // 5. prepare the flashback
 // 6. flashback to resolveTS
 func RecoverData(ctx context.Context, resolveTS uint64, allStores []*metapb.Store, mgr *conn.Mgr, progress glue.Progress, restoreTS uint64, concurrency uint32) (int, error) {
+	return utils.WithRetryV2(ctx, newRecoveryBackoffer(), func(ctx context.Context) (int, error) {
+		return doRecoveryData(ctx, resolveTS, allStores, mgr, progress, restoreTS, concurrency)
+	})
+}
+
+func doRecoveryData(ctx context.Context, resolveTS uint64, allStores []*metapb.Store, mgr *conn.Mgr, progress glue.Progress, restoreTS uint64, concurrency uint32) (int, error) {
+	var cancel context.CancelFunc
+	ctx, cancel = context.WithCancel(ctx)
+	defer cancel()
+
 	var recovery = NewRecovery(allStores, mgr, progress, concurrency)
 	if err := recovery.ReadRegionMeta(ctx); err != nil {
-		return 0, errors.Trace(err)
+		return 0, recoveryError{error: err, atStage: StageCollectingMeta}
 	}
 
 	totalRegions := recovery.GetTotalRegions()
 
-	if err := recovery.MakeRecoveryPlan(); err != nil {
-		return totalRegions, errors.Trace(err)
+	err := recovery.MakeRecoveryPlan()
+	if err != nil {
+		return totalRegions, recoveryError{error: err, atStage: StageMakingRecoveryPlan}
 	}
 
 	log.Info("recover the alloc id to pd", zap.Uint64("max alloc id", recovery.MaxAllocID))
 	if err := recovery.mgr.RecoverBaseAllocID(ctx, recovery.MaxAllocID); err != nil {
-		return totalRegions, errors.Trace(err)
+		return totalRegions, recoveryError{error: err, atStage: StageResetPDAllocateID}
 	}
 
 	// Once TiKV shuts down and reboot then, it may be left with no leader because of the recovery mode.
 	// This wathcher will retrigger `RecoveryRegions` for those stores.
 	recovery.SpawnTiKVShutDownWatchers(ctx)
 	if err := recovery.RecoverRegions(ctx); err != nil {
-		return totalRegions, errors.Trace(err)
+		return totalRegions, recoveryError{error: err, atStage: StageRecovering}
 	}
 
 	if err := recovery.WaitApply(ctx); err != nil {
-		return totalRegions, errors.Trace(err)
+		return totalRegions, recoveryError{error: err, atStage: StageRecovering}
 	}
-
-	if err := recovery.PrepareFlashbackToVersion(ctx, resolveTS, restoreTS-1); err != nil {
-		return totalRegions, errors.Trace(err)
+	err = recovery.PrepareFlashbackToVersion(ctx, resolveTS, restoreTS-1)
+	if err != nil {
+		return totalRegions, recoveryError{error: err, atStage: StageFlashback}
 	}
 
 	if err := recovery.FlashbackToVersion(ctx, resolveTS, restoreTS); err != nil {
-		return totalRegions, errors.Trace(err)
+		return totalRegions, recoveryError{error: err, atStage: StageFlashback}
 	}
 
 	return totalRegions, nil

br/pkg/task/restore_data.go

@@ -146,6 +146,8 @@
 	// restore tikv data from a snapshot volume
 	var totalRegions int
 
+	// Roughly handle the case that some TiKVs are rebooted during making plan.
+	// Generally,
 	totalRegions, err = restore.RecoverData(ctx, resolveTS, allStores, mgr, progress, restoreTS, cfg.Concurrency)
 	if err != nil {
 		return errors.Trace(err)

br/pkg/utils/backoff.go

@@ -72,6 +72,10 @@
 	return backoff
 }
 
+func (rs *RetryState) GiveUp() {
+	rs.retryTimes = rs.maxRetry
+}
+
 // InitialRetryState make the initial state for retrying.
 func InitialRetryState(maxRetryTimes int, initialBackoff, maxBackoff time.Duration) RetryState {
 	return RetryState{

br/pkg/utils/retry.go

@@ -34,6 +34,8 @@ var retryableServerError = []string{
 // RetryableFunc presents a retryable operation.
 type RetryableFunc func() error
 
+type RetryableFuncV2[T any] func(context.Context) (T, error)
+
 // Backoffer implements a backoff policy for retrying operations.
 type Backoffer interface {
 	// NextBackoff returns a duration to wait before retrying again
@@ -51,20 +53,37 @@ func WithRetry(
 	retryableFunc RetryableFunc,
 	backoffer Backoffer,
 ) error {
+	_, err := WithRetryV2[struct{}](ctx, backoffer, func(ctx context.Context) (struct{}, error) {
+		innerErr := retryableFunc()
+		return struct{}{}, innerErr
+	})
+	return err
+}
+
+// WithRetryV2 retries a given operation with a backoff policy.
+//
+// Returns the returned value if `retryableFunc` succeeded at least once. Otherwise, returns a
+// multierr that containing all errors encountered.
+// Comparing with `WithRetry`, this function reordered the argument order and supports catching the return value.
+func WithRetryV2[T any](
+	ctx context.Context,
+	backoffer Backoffer,
+	fn RetryableFuncV2[T],
+) (T, error) {
 	var allErrors error
 	for backoffer.Attempt() > 0 {
-		err := retryableFunc()
+		res, err := fn(ctx)
 		if err == nil {
-			return nil
+			return res, nil
 		}
 		allErrors = multierr.Append(allErrors, err)
 		select {
 		case <-ctx.Done():
-			return allErrors // nolint:wrapcheck
+			return *new(T), allErrors
 		case <-time.After(backoffer.NextBackoff(err)):
 		}
 	}
-	return allErrors // nolint:wrapcheck
+	return *new(T), allErrors // nolint:wrapcheck
 }
 
 // MessageIsRetryableStorageError checks whether the message returning from TiKV is retryable ExternalStorageError.