Support faster Get, retry flushes on error

blockstore/autobatch.go

@@ -3,6 +3,7 @@ package blockstore
 import (
 	"context"
 	"sync"
+	"time"
 
 	"golang.org/x/xerrors"
 
@@ -15,24 +16,39 @@ import (
 var autolog = log.Named("auto")
 
 type AutobatchBlockstore struct {
-	bufferedBlks   []block.Block
+	// TODO: drop if memory consumption is too high
 	addedCids map[cid.Cid]struct{}
-	bufferedBlksLk sync.Mutex
+
+	bufferedLk          sync.Mutex
+	bufferedBlksOrdered []block.Block
+	bufferedBlksMap     map[cid.Cid]block.Block
+
+	flushingLk      sync.Mutex
+	flushingBlksMap map[cid.Cid]block.Block
+
 	flushCh         chan struct{}
 	flushErr        error
-	shutdownCh     chan struct{}
+	flushRetryDelay time.Duration
 	flushCtx        context.Context
+	shutdownCh      chan struct{}
+
 	backingBs Blockstore
+
 	bufferCapacity int
 	bufferSize     int
 }
 
 func NewAutobatch(ctx context.Context, backingBs Blockstore, bufferCapacity int) *AutobatchBlockstore {
 	bs := &AutobatchBlockstore{
+		addedCids:       make(map[cid.Cid]struct{}),
 		backingBs:       backingBs,
 		bufferCapacity:  bufferCapacity,
-		addedCids:      make(map[cid.Cid]struct{}),
+		bufferedBlksMap: make(map[cid.Cid]block.Block),
+		flushingBlksMap: make(map[cid.Cid]block.Block),
 		flushCtx:        ctx,
+		flushCh:         make(chan struct{}, 1),
+		// could be made configable
+		flushRetryDelay: time.Second * 5,
 	}
 
 	go bs.flushWorker()
@@ -41,11 +57,12 @@ func NewAutobatch(ctx context.Context, backingBs Blockstore, bufferCapacity int)
 }
 
 func (bs *AutobatchBlockstore) Put(ctx context.Context, blk block.Block) error {
-	bs.bufferedBlksLk.Lock()
+	bs.bufferedLk.Lock()
 	_, ok := bs.addedCids[blk.Cid()]
 	if !ok {
-		bs.bufferedBlks = append(bs.bufferedBlks, blk)
 		bs.addedCids[blk.Cid()] = struct{}{}
+		bs.bufferedBlksOrdered = append(bs.bufferedBlksOrdered, blk)
+		bs.bufferedBlksMap[blk.Cid()] = blk
 		bs.bufferSize += len(blk.RawData())
 		if bs.bufferSize >= bs.bufferCapacity {
 			// signal that a flush is appropriate, may be ignored
@@ -56,7 +73,7 @@ func (bs *AutobatchBlockstore) Put(ctx context.Context, blk block.Block) error {
 			}
 		}
 	}
-	bs.bufferedBlksLk.Unlock()
+	bs.bufferedLk.Unlock()
 	return nil
 }
 
@@ -65,9 +82,16 @@ func (bs *AutobatchBlockstore) flushWorker() {
 		select {
 		case <-bs.flushCh:
 			putErr := bs.doFlush(bs.flushCtx)
-			if putErr != nil {
-				autolog.Errorf("FLUSH ERRORED: %w", putErr)
-				bs.flushErr = xerrors.Errorf("%w, put error: %w", bs.flushErr, putErr)
+			for putErr != nil {
+				select {
+				case <-bs.shutdownCh:
+					bs.flushErr = putErr
+					return
+				default:
+					autolog.Errorf("FLUSH ERRORED: %w, retrying in %v", putErr, bs.flushRetryDelay)
+					time.Sleep(bs.flushRetryDelay)
+					putErr = bs.doFlush(bs.flushCtx)
+				}
 			}
 		case <-bs.shutdownCh:
 			return
@@ -76,20 +100,24 @@ func (bs *AutobatchBlockstore) flushWorker() {
 }
 
 func (bs *AutobatchBlockstore) doFlush(ctx context.Context) error {
-	bs.bufferedBlksLk.Lock()
+	bs.bufferedLk.Lock()
+	bs.flushingLk.Lock()
 	// We do NOT clear addedCids here, because its purpose is to expedite Puts
-	toFlush := bs.bufferedBlks
-	bs.bufferedBlks = []block.Block{}
-	bs.bufferedBlksLk.Unlock()
-	return bs.backingBs.PutMany(ctx, toFlush)
-}
-
-func (bs *AutobatchBlockstore) Flush(ctx context.Context) error {
-	return bs.doFlush(ctx)
+	flushingBlksOrdered := bs.bufferedBlksOrdered
+	bs.flushingBlksMap = bs.bufferedBlksMap
+	bs.bufferedBlksOrdered = []block.Block{}
+	bs.bufferedBlksMap = make(map[cid.Cid]block.Block)
+	bs.bufferedLk.Unlock()
+	bs.flushingLk.Unlock()
+	return bs.backingBs.PutMany(ctx, flushingBlksOrdered)
 }
 
 func (bs *AutobatchBlockstore) Shutdown(ctx context.Context) error {
+	// request one last flush of the worker
+	bs.flushCh <- struct{}{}
+	// shutdown the flush worker
 	bs.shutdownCh <- struct{}{}
+	// if it ever errored, this method fails
 	if bs.flushErr != nil {
 		return xerrors.Errorf("flushWorker errored: %w", bs.flushErr)
 	}
@@ -98,8 +126,8 @@ func (bs *AutobatchBlockstore) Shutdown(ctx context.Context) error {
 	return bs.doFlush(ctx)
 }
 
-// May be very slow if the cid queried wasn't in the backingBs at the time of creation of this AutobatchBlockstore
 func (bs *AutobatchBlockstore) Get(ctx context.Context, c cid.Cid) (block.Block, error) {
+	// may seem backward to check the backingBs first, but that is the likeliest case
 	blk, err := bs.backingBs.Get(ctx, c)
 	if err == nil {
 		return blk, nil
@@ -109,16 +137,24 @@ func (bs *AutobatchBlockstore) Get(ctx context.Context, c cid.Cid) (block.Block,
 		return blk, err
 	}
 
-	bs.Flush(ctx)
-	return bs.backingBs.Get(ctx, c)
+	bs.flushingLk.Lock()
+	v, ok := bs.flushingBlksMap[c]
+	bs.flushingLk.Unlock()
+	if ok {
+		return v, nil
+	}
+
+	bs.bufferedLk.Lock()
+	v, ok = bs.bufferedBlksMap[c]
+	bs.bufferedLk.Unlock()
+	if ok {
+		return v, nil
+	}
+
+	return nil, ErrNotFound
 }
 
 func (bs *AutobatchBlockstore) DeleteBlock(context.Context, cid.Cid) error {
-	// if we wanted to support this, we would have to:
-	// - flush
-	// - delete from the backingBs (if present)
-	// - remove from addedCids (if present)
-	// - if present in addedCids, also walk bufferedBlks and remove if present
 	return xerrors.New("deletion is unsupported")
 }
 
@@ -159,8 +195,8 @@ func (bs *AutobatchBlockstore) PutMany(ctx context.Context, blks []block.Block)
 }
 
 func (bs *AutobatchBlockstore) AllKeysChan(ctx context.Context) (<-chan cid.Cid, error) {
-	bs.Flush(ctx)
-	return bs.backingBs.AllKeysChan(ctx)
+	return nil, xerrors.New("unsupported")
+
 }
 
 func (bs *AutobatchBlockstore) HashOnRead(enabled bool) {
@@ -168,6 +204,5 @@ func (bs *AutobatchBlockstore) HashOnRead(enabled bool) {
 }
 
 func (bs *AutobatchBlockstore) View(ctx context.Context, cid cid.Cid, callback func([]byte) error) error {
-	bs.Flush(ctx)
-	return bs.backingBs.View(ctx, cid, callback)
+	return xerrors.New("unsupported")
 }

chain/consensus/filcns/upgrades.go

@@ -1297,11 +1297,7 @@ func upgradeActorsV7Common(
 		return cid.Undef, xerrors.Errorf("failed to persist new state root: %w", err)
 	}
 
-	// Persist the new tree. Blocks until the entire writeStore is in the state blockstore.
-	if err := writeStore.Flush(ctx); err != nil {
-		return cid.Undef, xerrors.Errorf("failed to flush writestore: %w", err)
-	}
-
+	// Persists the new tree and shuts down the flush worker
 	if err := writeStore.Shutdown(ctx); err != nil {
 		return cid.Undef, xerrors.Errorf("writeStore failed: %w", err)
 	}