etcdserver/*: changes to snapshots and wal logic to fix #10219

build

@@ -16,7 +16,7 @@ GO_LDFLAGS="$GO_LDFLAGS -X ${REPO_PATH}/version.GitSHA=${GIT_SHA}"
 toggle_failpoints() {
 	mode="$1"
 	if command -v gofail >/dev/null 2>&1; then
-		gofail "$mode" etcdserver/ mvcc/backend/ wal/
+		gofail "$mode" etcdserver/ mvcc/backend/
 	elif [[ "$mode" != "disable" ]]; then
 		echo "FAILPOINTS set but gofail not found"
 		exit 1

etcdserver/raft.go

@@ -229,20 +229,20 @@ func (r *raftNode) start(rh *raftReadyHandler) {
 
 				if !raft.IsEmptySnap(rd.Snapshot) {
 					// gofail: var raftBeforeSaveSnap struct{}
-					if err := r.storage.SaveSnapshot(rd.Snapshot); err != nil {
+					if err := r.storage.SaveSnap(rd.Snapshot); err != nil {
 						r.lg.Fatal("failed to save Raft snapshot", zap.Error(err))
 					}
 					// gofail: var raftAfterSaveSnap struct{}
 				}
 
-				// gofail: var raftBeforeSaveAll struct{}
-				if err := r.storage.SaveAll(rd.HardState, rd.Entries, rd.Snapshot); err != nil {
+				// gofail: var raftBeforeSave struct{}
+				if err := r.storage.Save(rd.HardState, rd.Entries); err != nil {
 					r.lg.Fatal("failed to save Raft hard state and entries", zap.Error(err))
 				}
 				if !raft.IsEmptyHardState(rd.HardState) {
 					proposalsCommitted.Set(float64(rd.HardState.Commit))
 				}
-				// gofail: var raftAfterSaveAll struct{}
+				// gofail: var raftAfterSave struct{}
 
 				if !raft.IsEmptySnap(rd.Snapshot) {
 					// etcdserver now claim the snapshot has been persisted onto the disk

etcdserver/server.go

@@ -2178,6 +2178,11 @@ func (s *EtcdServer) snapshot(snapi uint64, confState raftpb.ConfState) {
 		if err = s.r.storage.SaveSnap(snap); err != nil {
 			lg.Panic("failed to save snapshot", zap.Error(err))
 		}
+
+		if err = s.r.storage.Release(snap); err != nil {
+			lg.Panic("failed to release wal", zap.Error(err))
+		}
+
 		lg.Info(
 			"saved snapshot",
 			zap.Uint64("snapshot-index", snap.Metadata.Index),

etcdserver/storage.go

@@ -36,12 +36,6 @@ type Storage interface {
 	SaveSnap(snap raftpb.Snapshot) error
 	// Close closes the Storage and performs finalization.
 	Close() error
-
-	// SaveSnapshot function saves only snapshot to the underlying stable storage.
-	SaveSnapshot(snap raftpb.Snapshot) error
-	// SaveAll function saves ents, snapshot and state to the underlying stable storage.
-	// SaveAll MUST block until st and ents are on stable storage.
-	SaveAll(st raftpb.HardState, ents []raftpb.Entry, snap raftpb.Snapshot) error
 	// Release release release the locked wal files since they will not be used.
 	Release(snap raftpb.Snapshot) error
 }
@@ -66,15 +60,7 @@ func (st *storage) SaveSnap(snap raftpb.Snapshot) error {
 	if err != nil {
 		return err
 	}
-	err = st.Snapshotter.SaveSnap(snap)
-	if err != nil {
-		return err
-	}
-	return st.WAL.ReleaseLockTo(snap.Metadata.Index)
-}
 
-// SaveSnapshot saves the snapshot to disk.
-func (st *storage) SaveSnapshot(snap raftpb.Snapshot) error {
 	return st.Snapshotter.SaveSnap(snap)
 }
 

wal/wal.go

@@ -870,72 +870,6 @@ func (w *WAL) SaveSnapshot(e walpb.Snapshot) error {
 	return w.sync()
 }
 
-func (w *WAL) SaveAll(st raftpb.HardState, ents []raftpb.Entry, snap raftpb.Snapshot) error {
-	w.mu.Lock()
-	defer w.mu.Unlock()
-
-	// short cut, do not call sync
-	if raft.IsEmptyHardState(st) && len(ents) == 0 && raft.IsEmptySnap(snap) {
-		return nil
-	}
-
-	mustSync := raft.MustSync(st, w.state, len(ents))
-
-	if !raft.IsEmptySnap(snap) {
-		mustSync = true
-	}
-
-	// 1. Save entries
-	// TODO(xiangli): no more reference operator
-	for i := range ents {
-		if err := w.saveEntry(&ents[i]); err != nil {
-			return err
-		}
-		// gofail: var raftAfterSaveWALFirstEntry struct{}
-	}
-	// gofail: var raftAfterSaveWALEntries struct{}
-
-	// 2. Save snapshot
-	if !raft.IsEmptySnap(snap) {
-		e := walpb.Snapshot{
-			Index: snap.Metadata.Index,
-			Term:  snap.Metadata.Term,
-		}
-
-		b := pbutil.MustMarshal(&e)
-
-		rec := &walpb.Record{Type: snapshotType, Data: b}
-		if err := w.encoder.encode(rec); err != nil {
-			return err
-		}
-
-		// update enti only when snapshot is ahead of last index
-		if w.enti < e.Index {
-			w.enti = e.Index
-		}
-		// gofail: var raftAfterSaveWALSnap struct{}
-	}
-
-	// 3. Save HardState
-	if err := w.saveState(&st); err != nil {
-		return err
-	}
-	// gofail: var raftAfterSaveWALState struct{}
-
-	curOff, err := w.tail().Seek(0, io.SeekCurrent)
-	if err != nil {
-		return err
-	}
-	if curOff < SegmentSizeBytes {
-		if mustSync {
-			return w.sync()
-		}
-		return nil
-	}
-
-	return w.cut()
-}
-
 func (w *WAL) saveCrc(prevCrc uint32) error {
 	return w.encoder.encode(&walpb.Record{Type: crcType, Crc: prevCrc})
 }