core, ethdb: introduce database sync function (#31703)

cmd/geth/dbcmd.go

@@ -1282,7 +1282,7 @@ func hbss2pbss(ctx *cli.Context) error {
 	defer stack.Close()
 
 	db := utils.MakeChainDatabase(ctx, stack, false, false)
-	db.BlockStore().Sync()
+	db.BlockStore().SyncAncient()
 	stateDiskDb := db.StateStore()
 	defer db.Close()
 

core/bench_test.go

@@ -183,7 +183,7 @@ func benchInsertChain(b *testing.B, disk bool, gen func(int, *BlockGen)) {
 	if !disk {
 		db = rawdb.NewMemoryDatabase()
 	} else {
-		pdb, err := pebble.New(b.TempDir(), 128, 128, "", false, true)
+		pdb, err := pebble.New(b.TempDir(), 128, 128, "", false)
 		if err != nil {
 			b.Fatalf("cannot create temporary database: %v", err)
 		}
@@ -304,7 +304,7 @@ func makeChainForBench(db ethdb.Database, genesis *Genesis, full bool, count uin
 func benchWriteChain(b *testing.B, full bool, count uint64) {
 	genesis := &Genesis{Config: params.AllEthashProtocolChanges}
 	for i := 0; i < b.N; i++ {
-		pdb, err := pebble.New(b.TempDir(), 1024, 128, "", false, true)
+		pdb, err := pebble.New(b.TempDir(), 1024, 128, "", false)
 		if err != nil {
 			b.Fatalf("error opening database: %v", err)
 		}
@@ -317,7 +317,7 @@ func benchWriteChain(b *testing.B, full bool, count uint64) {
 func benchReadChain(b *testing.B, full bool, count uint64) {
 	dir := b.TempDir()
 
-	pdb, err := pebble.New(dir, 1024, 128, "", false, true)
+	pdb, err := pebble.New(dir, 1024, 128, "", false)
 	if err != nil {
 		b.Fatalf("error opening database: %v", err)
 	}
@@ -333,7 +333,7 @@ func benchReadChain(b *testing.B, full bool, count uint64) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		pdb, err = pebble.New(dir, 1024, 128, "", false, true)
+		pdb, err = pebble.New(dir, 1024, 128, "", false)
 		if err != nil {
 			b.Fatalf("error opening database: %v", err)
 		}

core/blockchain.go

@@ -1119,17 +1119,16 @@ func (bc *BlockChain) setHeadBeyondRoot(head uint64, time uint64, root common.Ha
 		// Ignore the error here since light client won't hit this path
 		frozen, _ := bc.db.BlockStore().Ancients()
 		if num+1 <= frozen {
-			// Truncate all relative data(header, total difficulty, body, receipt
-			// and canonical hash) from ancient store.
-			if _, err := bc.db.BlockStore().TruncateHead(num); err != nil {
-				log.Crit("Failed to truncate ancient data", "number", num, "err", err)
-			}
-			// Remove the hash <-> number mapping from the active store.
-			rawdb.DeleteHeaderNumber(db, hash)
+			// The chain segment, such as the block header, canonical hash,
+			// body, and receipt, will be removed from the ancient store
+			// in one go.
+			//
+			// The hash-to-number mapping in the key-value store will be
+			// removed by the hc.SetHead function.
 		} else {
-			// Remove relative body and receipts from the active store.
-			// The header, total difficulty and canonical hash will be
-			// removed in the hc.SetHead function.
+			// Remove the associated body and receipts from the key-value store.
+			// The header, hash-to-number mapping, and canonical hash will be
+			// removed by the hc.SetHead function.
 			rawdb.DeleteBody(db, hash, num)
 			rawdb.DeleteBlobSidecars(db, hash, num)
 			rawdb.DeleteReceipts(db, hash, num)
@@ -1599,7 +1598,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 		size += writeSize
 
 		// Sync the ancient store explicitly to ensure all data has been flushed to disk.
-		if err := bc.db.BlockStore().Sync(); err != nil {
+		if err := bc.db.BlockStore().SyncAncient(); err != nil {
 			return 0, err
 		}
 		// Update the current snap block because all block data is now present in DB.

core/blockchain_repair_test.go

@@ -1767,7 +1767,7 @@ func testRepairWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme s
 	datadir := t.TempDir()
 	ancient := filepath.Join(datadir, "ancient")
 
-	pdb, err := pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}
@@ -1861,7 +1861,7 @@ func testRepairWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme s
 	chain.stopWithoutSaving()
 
 	// Start a new blockchain back up and see where the repair leads us
-	pdb, err = pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err = pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to reopen persistent key-value database: %v", err)
 	}
@@ -1926,7 +1926,7 @@ func testIssue23496(t *testing.T, scheme string) {
 	datadir := t.TempDir()
 	ancient := filepath.Join(datadir, "ancient")
 
-	pdb, err := pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}
@@ -1984,7 +1984,7 @@ func testIssue23496(t *testing.T, scheme string) {
 	chain.stopWithoutSaving()
 
 	// Start a new blockchain back up and see where the repair leads us
-	pdb, err = pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err = pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to reopen persistent key-value database: %v", err)
 	}

core/blockchain_sethead_test.go

@@ -1971,7 +1971,7 @@ func testSetHeadWithScheme(t *testing.T, tt *rewindTest, snapshots bool, scheme
 	datadir := t.TempDir()
 	ancient := filepath.Join(datadir, "ancient")
 
-	pdb, err := pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}

core/blockchain_snapshot_test.go

@@ -66,7 +66,7 @@ func (basic *snapshotTestBasic) prepare(t *testing.T) (*BlockChain, []*types.Blo
 	datadir := t.TempDir()
 	ancient := filepath.Join(datadir, "ancient")
 
-	pdb, err := pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}
@@ -257,7 +257,7 @@ func (snaptest *crashSnapshotTest) test(t *testing.T) {
 	chain.triedb.Close()
 
 	// Start a new blockchain back up and see where the repair leads us
-	pdb, err := pebble.New(snaptest.datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(snaptest.datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}

core/blockchain_test.go

@@ -2670,7 +2670,7 @@ func testSideImportPrunedBlocks(t *testing.T, scheme string) {
 	datadir := t.TempDir()
 	ancient := path.Join(datadir, "ancient")
 
-	pdb, err := pebble.New(datadir, 0, 0, "", false, true)
+	pdb, err := pebble.New(datadir, 0, 0, "", false)
 	if err != nil {
 		t.Fatalf("Failed to create persistent key-value database: %v", err)
 	}

core/headerchain.go

@@ -695,18 +695,51 @@ func (hc *HeaderChain) setHead(headBlock uint64, headTime uint64, updateFn Updat
 				hashes = append(hashes, hdr.Hash())
 			}
 			for _, hash := range hashes {
+				// Remove the associated block body and receipts if required.
+				//
+				// If the block is in the chain freezer, then this delete operation
+				// is actually ineffective.
 				if delFn != nil {
 					delFn(blockBatch, hash, num)
 				}
+				// Remove the hash->number mapping along with the header itself
 				rawdb.DeleteHeader(blockBatch, hash, num)
 				rawdb.DeleteTd(blockBatch, hash, num)
 			}
+			// Remove the number->hash mapping
 			rawdb.DeleteCanonicalHash(blockBatch, num)
 		}
 	}
 	// Flush all accumulated deletions.
 	if err := blockBatch.Write(); err != nil {
-		log.Crit("Failed to rewind block", "error", err)
+		log.Crit("Failed to commit batch in setHead", "err", err)
+	}
+	// Explicitly flush the pending writes in the key-value store to disk, ensuring
+	// data durability of the previous deletions.
+	if err := hc.chainDb.SyncKeyValue(); err != nil {
+		log.Crit("Failed to sync the key-value store in setHead", "err", err)
+	}
+	// Truncate the excessive chain segments in the ancient store.
+	// These are actually deferred deletions from the loop above.
+	//
+	// This step must be performed after synchronizing the key-value store;
+	// otherwise, in the event of a panic, it's theoretically possible to
+	// lose recent key-value store writes while the ancient store deletions
+	// remain, leading to data inconsistency, e.g., the gap between the key
+	// value store and ancient can be created due to unclean shutdown.
+	if delFn != nil {
+		// Ignore the error here since light client won't hit this path
+		frozen, _ := hc.chainDb.Ancients()
+		header := hc.CurrentHeader()
+
+		// Truncate the excessive chain segment above the current chain head
+		// in the ancient store.
+		if header.Number.Uint64()+1 < frozen {
+			_, err := hc.chainDb.BlockStore().TruncateHead(header.Number.Uint64() + 1)
+			if err != nil {
+				log.Crit("Failed to truncate head block", "err", err)
+			}
+		}
 	}
 	// Clear out any stale content from the caches
 	hc.headerCache.Purge()

core/rawdb/chain_freezer.go

@@ -309,7 +309,7 @@ func (f *chainFreezer) freeze(db ethdb.KeyValueStore) {
 			continue
 		}
 		// Batch of blocks have been frozen, flush them before wiping from key-value store
-		if err := f.Sync(); err != nil {
+		if err := f.SyncAncient(); err != nil {
 			log.Crit("Failed to flush frozen tables", "err", err)
 		}
 		// Wipe out all data from the active database

core/rawdb/database.go

@@ -235,8 +235,8 @@ func (db *nofreezedb) ResetTable(kind string, startAt uint64, onlyEmpty bool) er
 	return errNotSupported
 }
 
-// Sync returns an error as we don't have a backing chain freezer.
-func (db *nofreezedb) Sync() error {
+// SyncAncient returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) SyncAncient() error {
 	return errNotSupported
 }
 
@@ -391,8 +391,8 @@ func (db *emptyfreezedb) ResetTable(kind string, startAt uint64, onlyEmpty bool)
 	return nil
 }
 
-// Sync returns nil for pruned db that we don't have a backing chain freezer.
-func (db *emptyfreezedb) Sync() error {
+// SyncAncient returns nil for pruned db that we don't have a backing chain freezer.
+func (db *emptyfreezedb) SyncAncient() error {
 	return nil
 }
 

core/rawdb/freezer.go

@@ -386,8 +386,8 @@ func (f *Freezer) TruncateTail(tail uint64) (uint64, error) {
 	return old, nil
 }
 
-// Sync flushes all data tables to disk.
-func (f *Freezer) Sync() error {
+// SyncAncient flushes all data tables to disk.
+func (f *Freezer) SyncAncient() error {
 	var errs []error
 	for _, table := range f.tables {
 		if err := table.Sync(); err != nil {
@@ -600,7 +600,7 @@ func (f *Freezer) ResetTable(kind string, startAt uint64, onlyEmpty bool) error
 		return nil
 	}
 
-	if err := f.Sync(); err != nil {
+	if err := f.SyncAncient(); err != nil {
 		return err
 	}
 	nt, err := t.resetItems(startAt - f.offset)

core/rawdb/freezer_memory.go

@@ -410,8 +410,8 @@ func (f *MemoryFreezer) TruncateTail(tail uint64) (uint64, error) {
 	return old, nil
 }
 
-// Sync flushes all data tables to disk.
-func (f *MemoryFreezer) Sync() error {
+// SyncAncient flushes all data tables to disk.
+func (f *MemoryFreezer) SyncAncient() error {
 	return nil
 }
 

core/rawdb/freezer_resettable.go

@@ -226,12 +226,12 @@ func (f *resettableFreezer) ResetTable(kind string, startAt uint64, onlyEmpty bo
 	return f.freezer.ResetTable(kind, startAt, onlyEmpty)
 }
 
-// Sync flushes all data tables to disk.
-func (f *resettableFreezer) Sync() error {
+// SyncAncient flushes all data tables to disk.
+func (f *resettableFreezer) SyncAncient() error {
 	f.lock.RLock()
 	defer f.lock.RUnlock()
 
-	return f.freezer.Sync()
+	return f.freezer.SyncAncient()
 }
 
 // AncientDatadir returns the path of the ancient store.

core/rawdb/freezer_test.go

@@ -493,7 +493,7 @@ func TestFreezerCloseSync(t *testing.T) {
 	if err := f.Close(); err != nil {
 		t.Fatal(err)
 	}
-	if err := f.Sync(); err == nil {
+	if err := f.SyncAncient(); err == nil {
 		t.Fatalf("want error, have nil")
 	} else if have, want := err.Error(), "[closed closed]"; have != want {
 		t.Fatalf("want %v, have %v", have, want)

core/rawdb/prunedfreezer.go

@@ -106,7 +106,7 @@ func (f *prunedfreezer) repair(datadir string) error {
 	log.Info("Read ancient db item counts", "items", minItems, "frozen", maxOffset)
 
 	atomic.StoreUint64(&f.frozen, maxOffset)
-	if err := f.Sync(); err != nil {
+	if err := f.SyncAncient(); err != nil {
 		return nil
 	}
 	return nil
@@ -117,7 +117,7 @@ func (f *prunedfreezer) Close() error {
 	var err error
 	f.closeOnce.Do(func() {
 		close(f.quit)
-		f.Sync()
+		f.SyncAncient()
 		err = f.instanceLock.Release()
 	})
 	return err
@@ -200,8 +200,8 @@ func (f *prunedfreezer) TruncateTail(tail uint64) (uint64, error) {
 	return 0, errNotSupported
 }
 
-// Sync flushes meta data tables to disk.
-func (f *prunedfreezer) Sync() error {
+// SyncAncient flushes meta data tables to disk.
+func (f *prunedfreezer) SyncAncient() error {
 	WriteFrozenOfAncientFreezer(f.db, atomic.LoadUint64(&f.frozen))
 	// compatible offline prune blocks tool
 	WriteOffSetOfCurrentAncientFreezer(f.db, atomic.LoadUint64(&f.frozen))
@@ -315,7 +315,7 @@ func (f *prunedfreezer) freeze() {
 			ancients = append(ancients, hash)
 		}
 		// Batch of blocks have been frozen, flush them before wiping from leveldb
-		if err := f.Sync(); err != nil {
+		if err := f.SyncAncient(); err != nil {
 			log.Crit("Failed to flush frozen tables", "err", err)
 		}
 		backoff = f.frozen-first >= freezerBatchLimit

core/rawdb/table.go

@@ -143,10 +143,10 @@ func (t *table) TruncateTail(items uint64) (uint64, error) {
 	return t.db.TruncateTail(items)
 }
 
-// Sync is a noop passthrough that just forwards the request to the underlying
+// SyncAncient is a noop passthrough that just forwards the request to the underlying
 // database.
-func (t *table) Sync() error {
-	return t.db.Sync()
+func (t *table) SyncAncient() error {
+	return t.db.SyncAncient()
 }
 
 // AncientDatadir returns the ancient datadir of the underlying database.
@@ -224,6 +224,12 @@ func (t *table) Compact(start []byte, limit []byte) error {
 	return t.db.Compact(start, limit)
 }
 
+// SyncKeyValue ensures that all pending writes are flushed to disk,
+// guaranteeing data durability up to the point.
+func (t *table) SyncKeyValue() error {
+	return t.db.SyncKeyValue()
+}
+
 // NewBatch creates a write-only database that buffers changes to its host db
 // until a final write is called, each operation prefixing all keys with the
 // pre-configured string.

ethdb/database.go

@@ -54,6 +54,13 @@ type KeyValueStater interface {
 	Stat() (string, error)
 }
 
+// KeyValueSyncer wraps the SyncKeyValue method of a backing data store.
+type KeyValueSyncer interface {
+	// SyncKeyValue ensures that all pending writes are flushed to disk,
+	// guaranteeing data durability up to the point.
+	SyncKeyValue() error
+}
+
 // Compacter wraps the Compact method of a backing data store.
 type Compacter interface {
 	// Compact flattens the underlying data store for the given key range. In essence,
@@ -72,6 +79,7 @@ type KeyValueStore interface {
 	KeyValueReader
 	KeyValueWriter
 	KeyValueStater
+	KeyValueSyncer
 	KeyValueRangeDeleter
 	Batcher
 	Iteratee
@@ -129,6 +137,9 @@ type AncientWriter interface {
 	// The integer return value is the total size of the written data.
 	ModifyAncients(func(AncientWriteOp) error) (int64, error)
 
+	// SyncAncient flushes all in-memory ancient store data to disk.
+	SyncAncient() error
+
 	// TruncateHead discards all but the first n ancient data from the ancient store.
 	// After the truncation, the latest item can be accessed it item_n-1(start from 0).
 	TruncateHead(n uint64) (uint64, error)
@@ -140,9 +151,6 @@ type AncientWriter interface {
 	// will be removed all together.
 	TruncateTail(n uint64) (uint64, error)
 
-	// Sync flushes all in-memory ancient store data to disk.
-	Sync() error
-
 	// TruncateTableTail will truncate certain table to new tail
 	TruncateTableTail(kind string, tail uint64) (uint64, error)