// apply takes entries received from Raft (after it has been committed) and
// applies them to the current state of the EtcdServer.
// The given entries should not be empty.
func (s *EtcdServer) apply(es []raftpb.Entry, confState *raftpb.ConfState) (uint64, bool) {
var applied uint64
var shouldstop bool
var err error
for i := range es {
e := es[i]
switch e.Type {
case raftpb.EntryNormal:
var r pb.Request
pbutil.MustUnmarshal(&r, e.Data)
s.w.Trigger(r.ID, s.applyRequest(r))
case raftpb.EntryConfChange:
var cc raftpb.ConfChange
pbutil.MustUnmarshal(&cc, e.Data)
shouldstop, err = s.applyConfChange(cc, confState)
s.w.Trigger(cc.ID, err)
default:
log.Panicf("entry type should be either EntryNormal or EntryConfChange")
}
atomic.StoreUint64(&s.r.index, e.Index)
atomic.StoreUint64(&s.r.term, e.Term)
applied = e.Index
}
return applied, shouldstop
}
// apply takes entries received from Raft (after it has been committed) and
// applies them to the current state of the EtcdServer.
// The given entries should not be empty.
func (s *EtcdServer) apply(es []raftpb.Entry, confState *raftpb.ConfState) (uint64, bool) {
var applied uint64
var shouldstop bool
var err error
for i := range es {
e := es[i]
switch e.Type {
case raftpb.EntryNormal:
// raft state machine may generate noop entry when leader confirmation.
// skip it in advance to avoid some potential bug in the future
if len(e.Data) == 0 {
select {
case s.forceVersionC <- struct{}{}:
default:
}
break
}
var r pb.Request
pbutil.MustUnmarshal(&r, e.Data)
s.w.Trigger(r.ID, s.applyRequest(r))
case raftpb.EntryConfChange:
var cc raftpb.ConfChange
pbutil.MustUnmarshal(&cc, e.Data)
shouldstop, err = s.applyConfChange(cc, confState)
s.w.Trigger(cc.ID, err)
default:
plog.Panicf("entry type should be either EntryNormal or EntryConfChange")
}
atomic.StoreUint64(&s.r.index, e.Index)
atomic.StoreUint64(&s.r.term, e.Term)
applied = e.Index
}
return applied, shouldstop
}
func readWAL(waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID, st raftpb.HardState, ents []raftpb.Entry) {
var (
err error
wmetadata []byte
)
repaired := false
for {
if w, err = wal.Open(waldir, snap); err != nil {
plog.Fatalf("open wal error: %v", err)
}
if wmetadata, st, ents, err = w.ReadAll(); err != nil {
w.Close()
// we can only repair ErrUnexpectedEOF and we never repair twice.
if repaired || err != io.ErrUnexpectedEOF {
plog.Fatalf("read wal error (%v) and cannot be repaired", err)
}
if !wal.Repair(waldir) {
plog.Fatalf("WAL error (%v) cannot be repaired", err)
} else {
plog.Infof("repaired WAL error (%v)", err)
repaired = true
}
continue
}
break
}
var metadata pb.Metadata
pbutil.MustUnmarshal(&metadata, wmetadata)
id = types.ID(metadata.NodeID)
cid = types.ID(metadata.ClusterID)
return
}
// getIDs returns an ordered set of IDs included in the given snapshot and
// the entries. The given snapshot/entries can contain two kinds of
// ID-related entry:
// - ConfChangeAddNode, in which case the contained ID will be added into the set.
// - ConfChangeAddRemove, in which case the contained ID will be removed from the set.
func getIDs(snap *raftpb.Snapshot, ents []raftpb.Entry) []uint64 {
ids := make(map[uint64]bool)
if snap != nil {
for _, id := range snap.Metadata.ConfState.Nodes {
ids[id] = true
}
}
for _, e := range ents {
if e.Type != raftpb.EntryConfChange {
continue
}
var cc raftpb.ConfChange
pbutil.MustUnmarshal(&cc, e.Data)
switch cc.Type {
case raftpb.ConfChangeAddNode:
ids[cc.NodeID] = true
case raftpb.ConfChangeRemoveNode:
delete(ids, cc.NodeID)
default:
log.Panicf("ConfChange Type should be either ConfChangeAddNode or ConfChangeRemoveNode!")
}
}
sids := make(types.Uint64Slice, 0)
for id := range ids {
sids = append(sids, id)
}
sort.Sort(sids)
return []uint64(sids)
}
func readWAL(waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID, st raftpb.HardState, ents []raftpb.Entry) {
var err error
if w, err = wal.Open(waldir, snap); err != nil {
log.Fatalf("etcdserver: open wal error: %v", err)
}
var wmetadata []byte
if wmetadata, st, ents, err = w.ReadAll(); err != nil {
log.Fatalf("etcdserver: read wal error: %v", err)
}
var metadata pb.Metadata
pbutil.MustUnmarshal(&metadata, wmetadata)
id = types.ID(metadata.NodeID)
cid = types.ID(metadata.ClusterID)
return
}
// ReadAll reads out all records of the current WAL.
// If it cannot read out the expected snap, it will return ErrSnapshotNotFound.
// If loaded snap doesn't match with the expected one, it will return
// all the records and error ErrSnapshotMismatch.
// TODO: detect not-last-snap error.
// TODO: maybe loose the checking of match.
// After ReadAll, the WAL will be ready for appending new records.
func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.Entry, err error) {
rec := &walpb.Record{}
decoder := w.decoder
var match bool
for err = decoder.decode(rec); err == nil; err = decoder.decode(rec) {
switch rec.Type {
case entryType:
e := mustUnmarshalEntry(rec.Data)
if e.Index > w.start.Index {
ents = append(ents[:e.Index-w.start.Index-1], e)
}
w.enti = e.Index
case stateType:
state = mustUnmarshalState(rec.Data)
case metadataType:
if metadata != nil && !reflect.DeepEqual(metadata, rec.Data) {
state.Reset()
return nil, state, nil, ErrMetadataConflict
}
metadata = rec.Data
case crcType:
crc := decoder.crc.Sum32()
// current crc of decoder must match the crc of the record.
// do no need to match 0 crc, since the decoder is a new one at this case.
if crc != 0 && rec.Validate(crc) != nil {
state.Reset()
return nil, state, nil, ErrCRCMismatch
}
decoder.updateCRC(rec.Crc)
case snapshotType:
var snap walpb.Snapshot
pbutil.MustUnmarshal(&snap, rec.Data)
if snap.Index == w.start.Index {
if snap.Term != w.start.Term {
state.Reset()
return nil, state, nil, ErrSnapshotMismatch
}
match = true
}
default:
state.Reset()
return nil, state, nil, fmt.Errorf("unexpected block type %d", rec.Type)
}
}
if err != io.EOF {
state.Reset()
return nil, state, nil, err
}
err = nil
if !match {
err = ErrSnapshotNotFound
}
// close decoder, disable reading
w.decoder.close()
w.start = walpb.Snapshot{}
w.metadata = metadata
// create encoder (chain crc with the decoder), enable appending
w.encoder = newEncoder(w.f, w.decoder.lastCRC())
w.decoder = nil
return metadata, state, ents, err
}
func (dec *msgAppV2Decoder) decode() (raftpb.Message, error) {
var (
m raftpb.Message
typ uint8
)
if _, err := io.ReadFull(dec.r, dec.uint8buf); err != nil {
return m, err
}
typ = uint8(dec.uint8buf[0])
switch typ {
case msgTypeLinkHeartbeat:
return linkHeartbeatMessage, nil
case msgTypeAppEntries:
m = raftpb.Message{
Type: raftpb.MsgApp,
From: uint64(dec.remote),
To: uint64(dec.local),
Term: dec.term,
LogTerm: dec.term,
Index: dec.index,
}
// decode entries
if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
return m, err
}
l := binary.BigEndian.Uint64(dec.uint64buf)
m.Entries = make([]raftpb.Entry, int(l))
for i := 0; i < int(l); i++ {
if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
return m, err
}
size := binary.BigEndian.Uint64(dec.uint64buf)
var buf []byte
if size < msgAppV2BufSize {
buf = dec.buf[:size]
if _, err := io.ReadFull(dec.r, buf); err != nil {
return m, err
}
} else {
buf = make([]byte, int(size))
if _, err := io.ReadFull(dec.r, buf); err != nil {
return m, err
}
}
dec.index++
// 1 alloc
pbutil.MustUnmarshal(&m.Entries[i], buf)
}
// decode commit index
if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
return m, err
}
m.Commit = binary.BigEndian.Uint64(dec.uint64buf)
case msgTypeApp:
var size uint64
if err := binary.Read(dec.r, binary.BigEndian, &size); err != nil {
return m, err
}
buf := make([]byte, int(size))
if _, err := io.ReadFull(dec.r, buf); err != nil {
return m, err
}
pbutil.MustUnmarshal(&m, buf)
dec.term = m.Term
dec.index = m.Index
if l := len(m.Entries); l > 0 {
dec.index = m.Entries[l-1].Index
}
default:
return m, fmt.Errorf("failed to parse type %d in msgappv2 stream", typ)
}
return m, nil
}
func mustUnmarshalState(d []byte) raftpb.HardState {
var s raftpb.HardState
pbutil.MustUnmarshal(&s, d)
return s
}
func mustUnmarshalEntry(d []byte) raftpb.Entry {
var e raftpb.Entry
pbutil.MustUnmarshal(&e, d)
return e
}
// ReadAll reads out records of the current WAL.
// If opened in write mode, it must read out all records until EOF. Or an error
// will be returned.
// If opened in read mode, it will try to read all records if possible.
// If it cannot read out the expected snap, it will return ErrSnapshotNotFound.
// If loaded snap doesn't match with the expected one, it will return
// all the records and error ErrSnapshotMismatch.
// TODO: detect not-last-snap error.
// TODO: maybe loose the checking of match.
// After ReadAll, the WAL will be ready for appending new records.
func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.Entry, err error) {
w.mu.Lock()
defer w.mu.Unlock()
rec := &walpb.Record{}
decoder := w.decoder
var match bool
for err = decoder.decode(rec); err == nil; err = decoder.decode(rec) {
switch rec.Type {
case entryType:
e := mustUnmarshalEntry(rec.Data)
if e.Index > w.start.Index {
ents = append(ents[:e.Index-w.start.Index-1], e)
}
w.enti = e.Index
case stateType:
state = mustUnmarshalState(rec.Data)
case metadataType:
if metadata != nil && !reflect.DeepEqual(metadata, rec.Data) {
state.Reset()
return nil, state, nil, ErrMetadataConflict
}
metadata = rec.Data
case crcType:
crc := decoder.crc.Sum32()
// current crc of decoder must match the crc of the record.
// do no need to match 0 crc, since the decoder is a new one at this case.
if crc != 0 && rec.Validate(crc) != nil {
state.Reset()
return nil, state, nil, ErrCRCMismatch
}
decoder.updateCRC(rec.Crc)
case snapshotType:
var snap walpb.Snapshot
pbutil.MustUnmarshal(&snap, rec.Data)
if snap.Index == w.start.Index {
if snap.Term != w.start.Term {
state.Reset()
return nil, state, nil, ErrSnapshotMismatch
}
match = true
}
default:
state.Reset()
return nil, state, nil, fmt.Errorf("unexpected block type %d", rec.Type)
}
}
switch w.f {
case nil:
// We do not have to read out all entries in read mode.
// The last record maybe a partial written one, so
// ErrunexpectedEOF might be returned.
if err != io.EOF && err != io.ErrUnexpectedEOF {
state.Reset()
return nil, state, nil, err
}
default:
// We must read all of the entries if WAL is opened in write mode.
if err != io.EOF {
state.Reset()
return nil, state, nil, err
}
}
err = nil
if !match {
err = ErrSnapshotNotFound
}
// close decoder, disable reading
w.decoder.close()
w.start = walpb.Snapshot{}
w.metadata = metadata
if w.f != nil {
// create encoder (chain crc with the decoder), enable appending
w.encoder = newEncoder(w.f, w.decoder.lastCRC())
w.decoder = nil
lastIndexSaved.Set(float64(w.enti))
}
return metadata, state, ents, err
}
