1// Copyright 2015 The etcd Authors 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package etcdserver 16 17import ( 18 "io" 19 20 pb "github.com/coreos/etcd/etcdserver/etcdserverpb" 21 "github.com/coreos/etcd/pkg/pbutil" 22 "github.com/coreos/etcd/pkg/types" 23 "github.com/coreos/etcd/raft/raftpb" 24 "github.com/coreos/etcd/snap" 25 "github.com/coreos/etcd/wal" 26 "github.com/coreos/etcd/wal/walpb" 27) 28 29type Storage interface { 30 // Save function saves ents and state to the underlying stable storage. 31 // Save MUST block until st and ents are on stable storage. 32 Save(st raftpb.HardState, ents []raftpb.Entry) error 33 // SaveSnap function saves snapshot to the underlying stable storage. 34 SaveSnap(snap raftpb.Snapshot) error 35 // Close closes the Storage and performs finalization. 36 Close() error 37} 38 39type storage struct { 40 *wal.WAL 41 *snap.Snapshotter 42} 43 44func NewStorage(w *wal.WAL, s *snap.Snapshotter) Storage { 45 return &storage{w, s} 46} 47 48// SaveSnap saves the snapshot to disk and release the locked 49// wal files since they will not be used. 50func (st *storage) SaveSnap(snap raftpb.Snapshot) error { 51 walsnap := walpb.Snapshot{ 52 Index: snap.Metadata.Index, 53 Term: snap.Metadata.Term, 54 } 55 err := st.WAL.SaveSnapshot(walsnap) 56 if err != nil { 57 return err 58 } 59 err = st.Snapshotter.SaveSnap(snap) 60 if err != nil { 61 return err 62 } 63 return st.WAL.ReleaseLockTo(snap.Metadata.Index) 64} 65 66func readWAL(waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID, st raftpb.HardState, ents []raftpb.Entry) { 67 var ( 68 err error 69 wmetadata []byte 70 ) 71 72 repaired := false 73 for { 74 if w, err = wal.Open(waldir, snap); err != nil { 75 plog.Fatalf("open wal error: %v", err) 76 } 77 if wmetadata, st, ents, err = w.ReadAll(); err != nil { 78 w.Close() 79 // we can only repair ErrUnexpectedEOF and we never repair twice. 80 if repaired || err != io.ErrUnexpectedEOF { 81 plog.Fatalf("read wal error (%v) and cannot be repaired", err) 82 } 83 if !wal.Repair(waldir) { 84 plog.Fatalf("WAL error (%v) cannot be repaired", err) 85 } else { 86 plog.Infof("repaired WAL error (%v)", err) 87 repaired = true 88 } 89 continue 90 } 91 break 92 } 93 var metadata pb.Metadata 94 pbutil.MustUnmarshal(&metadata, wmetadata) 95 id = types.ID(metadata.NodeID) 96 cid = types.ID(metadata.ClusterID) 97 return 98} 99