// append the given entries to the raft log.
func (r *Replica) append(batch engine.Engine, entries []raftpb.Entry) error {
if len(entries) == 0 {
return nil
}
for _, ent := range entries {
err := engine.MVCCPutProto(batch, nil, keys.RaftLogKey(r.RangeID, ent.Index),
roachpb.ZeroTimestamp, nil, &ent)
if err != nil {
return err
}
}
lastIndex := entries[len(entries)-1].Index
prevLastIndex := atomic.LoadUint64(&r.lastIndex)
// Delete any previously appended log entries which never committed.
for i := lastIndex + 1; i <= prevLastIndex; i++ {
err := engine.MVCCDelete(batch, nil,
keys.RaftLogKey(r.RangeID, i), roachpb.ZeroTimestamp, nil)
if err != nil {
return err
}
}
// Commit the batch and update the last index.
if err := setLastIndex(batch, r.RangeID, lastIndex); err != nil {
return err
}
batch.Defer(func() {
atomic.StoreUint64(&r.lastIndex, lastIndex)
})
return nil
}
func newRangeDataIterator(d *proto.RangeDescriptor, e engine.Engine) *rangeDataIterator {
// The first range in the keyspace starts at KeyMin, which includes the node-local
// space. We need the original StartKey to find the range metadata, but the
// actual data starts at LocalMax.
dataStartKey := d.StartKey
if d.StartKey.Equal(proto.KeyMin) {
dataStartKey = keys.LocalMax
}
ri := &rangeDataIterator{
ranges: []keyRange{
{
start: engine.MVCCEncodeKey(keys.MakeKey(keys.LocalRangeIDPrefix, encoding.EncodeUvarint(nil, uint64(d.RangeID)))),
end: engine.MVCCEncodeKey(keys.MakeKey(keys.LocalRangeIDPrefix, encoding.EncodeUvarint(nil, uint64(d.RangeID+1)))),
},
{
start: engine.MVCCEncodeKey(keys.MakeKey(keys.LocalRangePrefix, encoding.EncodeBytes(nil, d.StartKey))),
end: engine.MVCCEncodeKey(keys.MakeKey(keys.LocalRangePrefix, encoding.EncodeBytes(nil, d.EndKey))),
},
{
start: engine.MVCCEncodeKey(dataStartKey),
end: engine.MVCCEncodeKey(d.EndKey),
},
},
iter: e.NewIterator(),
}
ri.iter.Seek(ri.ranges[ri.curIndex].start)
ri.advance()
return ri
}
func newRangeDataIterator(r *Range, e engine.Engine) *rangeDataIterator {
r.RLock()
startKey := r.Desc().StartKey
if startKey.Equal(engine.KeyMin) {
startKey = engine.KeyLocalMax
}
endKey := r.Desc().EndKey
r.RUnlock()
ri := &rangeDataIterator{
ranges: []keyRange{
{
start: engine.MVCCEncodeKey(engine.MakeKey(engine.KeyLocalRangeIDPrefix, encoding.EncodeUvarint(nil, uint64(r.Desc().RaftID)))),
end: engine.MVCCEncodeKey(engine.MakeKey(engine.KeyLocalRangeIDPrefix, encoding.EncodeUvarint(nil, uint64(r.Desc().RaftID+1)))),
},
{
start: engine.MVCCEncodeKey(engine.MakeKey(engine.KeyLocalRangeKeyPrefix, encoding.EncodeBytes(nil, startKey))),
end: engine.MVCCEncodeKey(engine.MakeKey(engine.KeyLocalRangeKeyPrefix, encoding.EncodeBytes(nil, endKey))),
},
{
start: engine.MVCCEncodeKey(startKey),
end: engine.MVCCEncodeKey(endKey),
},
},
iter: e.NewIterator(),
}
ri.iter.Seek(ri.ranges[ri.curIndex].start)
ri.advance()
return ri
}
// CopyFrom copies all the cached results from the originRangeID
// response cache into this one. Note that the cache will not be
// locked while copying is in progress. Failures decoding individual
// cache entries return an error. The copy is done directly using the
// engine instead of interpreting values through MVCC for efficiency.
func (rc *ResponseCache) CopyFrom(e engine.Engine, originRangeID proto.RangeID) error {
prefix := keys.ResponseCacheKey(originRangeID, nil) // response cache prefix
start := engine.MVCCEncodeKey(prefix)
end := engine.MVCCEncodeKey(prefix.PrefixEnd())
return e.Iterate(start, end, func(kv proto.RawKeyValue) (bool, error) {
// Decode the key into a cmd, skipping on error. Otherwise,
// write it to the corresponding key in the new cache.
cmdID, err := rc.decodeResponseCacheKey(kv.Key)
if err != nil {
return false, util.Errorf("could not decode a response cache key %s: %s",
proto.Key(kv.Key), err)
}
key := keys.ResponseCacheKey(rc.rangeID, &cmdID)
encKey := engine.MVCCEncodeKey(key)
// Decode the value, update the checksum and re-encode.
meta := &engine.MVCCMetadata{}
if err := gogoproto.Unmarshal(kv.Value, meta); err != nil {
return false, util.Errorf("could not decode response cache value %s [% x]: %s",
proto.Key(kv.Key), kv.Value, err)
}
meta.Value.Checksum = nil
meta.Value.InitChecksum(key)
_, _, err = engine.PutProto(e, encKey, meta)
return false, err
})
}
func newReplicaDataIterator(d *roachpb.RangeDescriptor, e engine.Engine) *replicaDataIterator {
// The first range in the keyspace starts at KeyMin, which includes the node-local
// space. We need the original StartKey to find the range metadata, but the
// actual data starts at LocalMax.
dataStartKey := d.StartKey.AsRawKey()
if d.StartKey.Equal(roachpb.RKeyMin) {
dataStartKey = keys.LocalMax
}
ri := &replicaDataIterator{
ranges: []keyRange{
{
start: engine.MVCCEncodeKey(keys.MakeRangeIDPrefix(d.RangeID)),
end: engine.MVCCEncodeKey(keys.MakeRangeIDPrefix(d.RangeID + 1)),
},
{
start: engine.MVCCEncodeKey(keys.MakeRangeKeyPrefix(d.StartKey)),
end: engine.MVCCEncodeKey(keys.MakeRangeKeyPrefix(d.EndKey)),
},
{
start: engine.MVCCEncodeKey(dataStartKey),
end: engine.MVCCEncodeKey(d.EndKey.AsRawKey()),
},
},
iter: e.NewIterator(),
}
ri.iter.Seek(ri.ranges[ri.curIndex].start)
ri.advance()
return ri
}
// CopyInto copies all the cached results from this response cache
// into the destRangeID response cache. Failures decoding individual
// cache entries return an error.
func (rc *ResponseCache) CopyInto(e engine.Engine, destRangeID roachpb.RangeID) error {
start := engine.MVCCEncodeKey(
keys.ResponseCacheKey(rc.rangeID, roachpb.KeyMin))
end := engine.MVCCEncodeKey(
keys.ResponseCacheKey(rc.rangeID, roachpb.KeyMax))
return e.Iterate(start, end, func(kv engine.MVCCKeyValue) (bool, error) {
// Decode the key into a cmd, skipping on error. Otherwise,
// write it to the corresponding key in the new cache.
family, err := rc.decodeResponseCacheKey(kv.Key)
if err != nil {
return false, util.Errorf("could not decode a response cache key %s: %s",
roachpb.Key(kv.Key), err)
}
key := keys.ResponseCacheKey(destRangeID, family)
encKey := engine.MVCCEncodeKey(key)
// Decode the value, update the checksum and re-encode.
meta := &engine.MVCCMetadata{}
if err := proto.Unmarshal(kv.Value, meta); err != nil {
return false, util.Errorf("could not decode response cache value %s [% x]: %s",
roachpb.Key(kv.Key), kv.Value, err)
}
meta.Value.Checksum = nil
meta.Value.InitChecksum(key)
_, _, err = engine.PutProto(e, encKey, meta)
return false, err
})
}
// InternalTruncateLog discards a prefix of the raft log.
func (r *Range) InternalTruncateLog(batch engine.Engine, ms *engine.MVCCStats, args *proto.InternalTruncateLogRequest, reply *proto.InternalTruncateLogResponse) {
// args.Index is the first index to keep.
term, err := r.Term(args.Index - 1)
if err != nil {
reply.SetGoError(err)
return
}
start := keys.RaftLogKey(r.Desc().RaftID, 0)
end := keys.RaftLogKey(r.Desc().RaftID, args.Index)
err = batch.Iterate(engine.MVCCEncodeKey(start), engine.MVCCEncodeKey(end),
func(kv proto.RawKeyValue) (bool, error) {
err := batch.Clear(kv.Key)
return false, err
})
if err != nil {
reply.SetGoError(err)
return
}
ts := proto.RaftTruncatedState{
Index: args.Index - 1,
Term: term,
}
err = engine.MVCCPutProto(batch, ms, keys.RaftTruncatedStateKey(r.Desc().RaftID),
proto.ZeroTimestamp, nil, &ts)
reply.SetGoError(err)
}
func loadRangeDescriptor(
db engine.Engine, rangeID roachpb.RangeID,
) (roachpb.RangeDescriptor, error) {
var desc roachpb.RangeDescriptor
handleKV := func(kv engine.MVCCKeyValue) (bool, error) {
if kv.Key.Timestamp == hlc.ZeroTimestamp {
// We only want values, not MVCCMetadata.
return false, nil
}
if err := checkRangeDescriptorKey(kv.Key); err != nil {
// Range descriptor keys are interleaved with others, so if it
// doesn't parse as a range descriptor just skip it.
return false, nil
}
if err := getProtoValue(kv.Value, &desc); err != nil {
return false, err
}
return desc.RangeID == rangeID, nil
}
// Range descriptors are stored by key, so we have to scan over the
// range-local data to find the one for this RangeID.
start := engine.MakeMVCCMetadataKey(keys.LocalRangePrefix)
end := engine.MakeMVCCMetadataKey(keys.LocalRangeMax)
if err := db.Iterate(start, end, handleKV); err != nil {
return roachpb.RangeDescriptor{}, err
}
if desc.RangeID == rangeID {
return desc, nil
}
return roachpb.RangeDescriptor{}, fmt.Errorf("range descriptor %d not found", rangeID)
}
func copySeqCache(e engine.Engine, srcID, dstID roachpb.RangeID, keyMin, keyMax engine.MVCCKey) error {
var scratch [64]byte
return e.Iterate(keyMin, keyMax,
func(kv engine.MVCCKeyValue) (bool, error) {
// Decode the key into a cmd, skipping on error. Otherwise,
// write it to the corresponding key in the new cache.
id, epoch, seq, err := decodeSequenceCacheMVCCKey(kv.Key, scratch[:0])
if err != nil {
return false, util.Errorf("could not decode a sequence cache key %s: %s",
kv.Key, err)
}
key := keys.SequenceCacheKey(dstID, id, epoch, seq)
encKey := engine.MakeMVCCMetadataKey(key)
// Decode the value, update the checksum and re-encode.
meta := &engine.MVCCMetadata{}
if err := proto.Unmarshal(kv.Value, meta); err != nil {
return false, util.Errorf("could not decode sequence cache value %s [% x]: %s",
kv.Key, kv.Value, err)
}
value := meta.Value()
value.ClearChecksum()
value.InitChecksum(key)
meta.RawBytes = value.RawBytes
_, _, err = engine.PutProto(e, encKey, meta)
return false, err
})
}
func newReplicaDataIterator(d *roachpb.RangeDescriptor, e engine.Engine) *replicaDataIterator {
ri := &replicaDataIterator{
ranges: makeReplicaKeyRanges(d),
Iterator: e.NewIterator(false),
}
ri.Seek(ri.ranges[ri.curIndex].start)
return ri
}
// AddStore creates a new store on the same Transport but doesn't create any ranges.
func (m *multiTestContext) addStore() {
idx := len(m.stores)
var clock *hlc.Clock
if len(m.clocks) > idx {
clock = m.clocks[idx]
} else {
clock = m.clock
m.clocks = append(m.clocks, clock)
}
var eng engine.Engine
var needBootstrap bool
if len(m.engines) > idx {
eng = m.engines[idx]
} else {
eng = engine.NewInMem(proto.Attributes{}, 1<<20)
m.engines = append(m.engines, eng)
needBootstrap = true
// Add an extra refcount to the engine so the underlying rocksdb instances
// aren't closed when stopping and restarting the stores.
// These refcounts are removed in Stop().
if err := eng.Open(); err != nil {
m.t.Fatal(err)
}
}
stopper := stop.NewStopper()
ctx := m.makeContext(idx)
store := storage.NewStore(ctx, eng, &proto.NodeDescriptor{NodeID: proto.NodeID(idx + 1)})
if needBootstrap {
err := store.Bootstrap(proto.StoreIdent{
NodeID: proto.NodeID(idx + 1),
StoreID: proto.StoreID(idx + 1),
}, stopper)
if err != nil {
m.t.Fatal(err)
}
// Bootstrap the initial range on the first store
if idx == 0 {
if err := store.BootstrapRange(nil); err != nil {
m.t.Fatal(err)
}
}
}
if err := store.Start(stopper); err != nil {
m.t.Fatal(err)
}
store.WaitForInit()
m.stores = append(m.stores, store)
if len(m.senders) == idx {
m.senders = append(m.senders, kv.NewLocalSender())
}
m.senders[idx].AddStore(store)
// Save the store identities for later so we can use them in
// replication operations even while the store is stopped.
m.idents = append(m.idents, store.Ident)
m.stoppers = append(m.stoppers, stopper)
}
// ClearData removes all persisted items stored in the cache.
func (sc *AbortCache) ClearData(e engine.Engine) error {
b := e.NewBatch()
defer b.Close()
_, err := engine.ClearRange(b, engine.MakeMVCCMetadataKey(sc.min()), engine.MakeMVCCMetadataKey(sc.max()))
if err != nil {
return err
}
return b.Commit()
}
func newReplicaDataIterator(d *roachpb.RangeDescriptor, e engine.Engine, replicatedOnly bool) *replicaDataIterator {
rangeFunc := makeAllKeyRanges
if replicatedOnly {
rangeFunc = makeReplicatedKeyRanges
}
ri := &replicaDataIterator{
ranges: rangeFunc(d),
Iterator: e.NewIterator(nil),
}
ri.Seek(ri.ranges[ri.curIndex].start)
return ri
}
// ComputeStatsForRange computes the stats for a given range by
// iterating over all key ranges for the given range that should
// be accounted for in its stats.
func ComputeStatsForRange(d *roachpb.RangeDescriptor, e engine.Engine, nowNanos int64) (engine.MVCCStats, error) {
iter := e.NewIterator(nil)
defer iter.Close()
ms := engine.MVCCStats{}
for _, r := range makeReplicatedKeyRanges(d) {
msDelta, err := iter.ComputeStats(r.start, r.end, nowNanos)
if err != nil {
return engine.MVCCStats{}, err
}
ms.Add(msDelta)
}
return ms, nil
}
// mergeTrigger is called on a successful commit of an AdminMerge
// transaction. It recomputes stats for the receiving range.
func (r *Range) mergeTrigger(batch engine.Engine, merge *proto.MergeTrigger) error {
if !bytes.Equal(r.Desc().StartKey, merge.UpdatedDesc.StartKey) {
return util.Errorf("range and updated range start keys do not match: %s != %s",
r.Desc().StartKey, merge.UpdatedDesc.StartKey)
}
if !r.Desc().EndKey.Less(merge.UpdatedDesc.EndKey) {
return util.Errorf("range end key is not less than the post merge end key: %s >= %s",
r.Desc().EndKey, merge.UpdatedDesc.EndKey)
}
if merge.SubsumedRaftID <= 0 {
return util.Errorf("subsumed raft ID must be provided: %d", merge.SubsumedRaftID)
}
// Copy the subsumed range's response cache to the subsuming one.
if err := r.respCache.CopyFrom(batch, merge.SubsumedRaftID); err != nil {
return util.Errorf("unable to copy response cache to new split range: %s", err)
}
// Compute stats for updated range.
now := r.rm.Clock().Timestamp()
iter := newRangeDataIterator(&merge.UpdatedDesc, batch)
ms, err := engine.MVCCComputeStats(iter, now.WallTime)
iter.Close()
if err != nil {
return util.Errorf("unable to compute stats for the range after merge: %s", err)
}
if err = r.stats.SetMVCCStats(batch, ms); err != nil {
return util.Errorf("unable to write MVCC stats: %s", err)
}
// Clear the timestamp cache. In the case that this replica and the
// subsumed replica each held their respective leader leases, we
// could merge the timestamp caches for efficiency. But it's unlikely
// and not worth the extra logic and potential for error.
r.Lock()
r.tsCache.Clear(r.rm.Clock())
r.Unlock()
batch.Defer(func() {
if err := r.rm.MergeRange(r, merge.UpdatedDesc.EndKey, merge.SubsumedRaftID); err != nil {
// Our in-memory state has diverged from the on-disk state.
log.Fatalf("failed to update store after merging range: %s", err)
}
})
return nil
}
// CopyFrom copies all the cached results from another response cache
// into this one. Note that the cache will not be locked while copying
// is in progress. Failures decoding individual cache entries return an
// error. The copy is done directly using the engine instead of interpreting
// values through MVCC for efficiency.
func (rc *ResponseCache) CopyFrom(e engine.Engine, originRaftID int64) error {
prefix := engine.ResponseCacheKey(originRaftID, nil) // response cache prefix
start := engine.MVCCEncodeKey(prefix)
end := engine.MVCCEncodeKey(prefix.PrefixEnd())
return e.Iterate(start, end, func(kv proto.RawKeyValue) (bool, error) {
// Decode the key into a cmd, skipping on error. Otherwise,
// write it to the corresponding key in the new cache.
cmdID, err := rc.decodeResponseCacheKey(kv.Key)
if err != nil {
return false, util.Errorf("could not decode a response cache key %q: %s", kv.Key, err)
}
encKey := engine.MVCCEncodeKey(engine.ResponseCacheKey(rc.raftID, &cmdID))
return false, rc.engine.Put(encKey, kv.Value)
})
}
func verifyCleanup(key proto.Key, coord *TxnCoordSender, eng engine.Engine, t *testing.T) {
if len(coord.txns) != 0 {
t.Errorf("expected empty transactions map; got %d", len(coord.txns))
}
if err := util.IsTrueWithin(func() bool {
meta := &engine.MVCCMetadata{}
ok, _, _, err := eng.GetProto(engine.MVCCEncodeKey(key), meta)
if err != nil {
t.Errorf("error getting MVCC metadata: %s", err)
}
return !ok || meta.Txn == nil
}, 500*time.Millisecond); err != nil {
t.Errorf("expected intents to be cleaned up within 500ms")
}
}
func copySeqCache(
e engine.Engine,
ms *engine.MVCCStats,
srcID, dstID roachpb.RangeID,
keyMin, keyMax engine.MVCCKey,
) (int, error) {
var scratch [64]byte
var count int
var meta engine.MVCCMetadata
// TODO(spencer): look into making this an MVCCIteration and writing
// the values using MVCC so we can avoid the ugliness of updating
// the MVCCStats by hand below.
err := e.Iterate(keyMin, keyMax,
func(kv engine.MVCCKeyValue) (bool, error) {
// Decode the key, skipping on error. Otherwise, write it to the
// corresponding key in the new cache.
txnID, err := decodeAbortCacheMVCCKey(kv.Key, scratch[:0])
if err != nil {
return false, util.Errorf("could not decode an abort cache key %s: %s", kv.Key, err)
}
key := keys.AbortCacheKey(dstID, txnID)
encKey := engine.MakeMVCCMetadataKey(key)
// Decode the MVCCMetadata value.
if err := proto.Unmarshal(kv.Value, &meta); err != nil {
return false, util.Errorf("could not decode mvcc metadata %s [% x]: %s", kv.Key, kv.Value, err)
}
value := meta.Value()
value.ClearChecksum()
value.InitChecksum(key)
meta.RawBytes = value.RawBytes
keyBytes, valBytes, err := engine.PutProto(e, encKey, &meta)
if err != nil {
return false, err
}
count++
if ms != nil {
ms.SysBytes += keyBytes + valBytes
ms.SysCount++
}
return false, nil
})
return count, err
}
func verifyCleanup(key proto.Key, coord *TxnCoordSender, eng engine.Engine, t *testing.T) {
util.SucceedsWithin(t, 500*time.Millisecond, func() error {
coord.Lock()
l := len(coord.txns)
coord.Unlock()
if l != 0 {
return fmt.Errorf("expected empty transactions map; got %d", l)
}
meta := &engine.MVCCMetadata{}
ok, _, _, err := eng.GetProto(engine.MVCCEncodeKey(key), meta)
if err != nil {
return fmt.Errorf("error getting MVCC metadata: %s", err)
}
if !ok || meta.Txn == nil {
return nil
}
return errors.New("intents not cleaned up")
})
}
func verifyCleanup(key roachpb.Key, coord *TxnCoordSender, eng engine.Engine, t *testing.T) {
util.SucceedsWithin(t, 500*time.Millisecond, func() error {
coord.Lock()
l := len(coord.txns)
coord.Unlock()
if l != 0 {
return fmt.Errorf("expected empty transactions map; got %d", l)
}
meta := &engine.MVCCMetadata{}
ok, _, _, err := eng.GetProto(engine.MakeMVCCMetadataKey(key), meta)
if err != nil {
return fmt.Errorf("error getting MVCC metadata: %s", err)
}
if ok && meta.Txn != nil {
return fmt.Errorf("found unexpected write intent: %s", meta)
}
return nil
})
}
// applySnapshot updates the replica based on the given snapshot.
// Returns the new last index.
func (r *Replica) applySnapshot(batch engine.Engine, snap raftpb.Snapshot) (uint64, error) {
snapData := roachpb.RaftSnapshotData{}
err := proto.Unmarshal(snap.Data, &snapData)
if err != nil {
return 0, err
}
rangeID := r.RangeID
// First, save the HardState. The HardState must not be changed
// because it may record a previous vote cast by this node. This is
// usually unnecessary because a snapshot is nearly always
// accompanied by a new HardState which incorporates both our former
// state and new information from the leader, but in the event that
// the HardState has not changed, we want to use our own previous
// HardState and not one that was transmitted via the snapshot.
hardStateKey := keys.RaftHardStateKey(rangeID)
hardState, _, err := engine.MVCCGet(batch, hardStateKey, roachpb.ZeroTimestamp, true /* consistent */, nil)
if err != nil {
return 0, err
}
// Extract the updated range descriptor.
desc := snapData.RangeDescriptor
// Delete everything in the range and recreate it from the snapshot.
// We need to delete any old Raft log entries here because any log entries
// that predate the snapshot will be orphaned and never truncated or GC'd.
iter := newReplicaDataIterator(&desc, batch, false /* !replicatedOnly */)
defer iter.Close()
for ; iter.Valid(); iter.Next() {
if err := batch.Clear(iter.Key()); err != nil {
return 0, err
}
}
// Determine the unreplicated key prefix so we can drop any
// unreplicated keys from the snapshot.
unreplicatedPrefix := keys.MakeRangeIDUnreplicatedPrefix(desc.RangeID)
// Write the snapshot into the range.
for _, kv := range snapData.KV {
if bytes.HasPrefix(kv.Key, unreplicatedPrefix) {
continue
}
mvccKey := engine.MVCCKey{
Key: kv.Key,
Timestamp: kv.Timestamp,
}
if err := batch.Put(mvccKey, kv.Value); err != nil {
return 0, err
}
}
// Write the snapshot's Raft log into the range.
if _, err := r.append(batch, 0, snapData.LogEntries); err != nil {
return 0, err
}
// Restore the saved HardState.
if hardState == nil {
err := engine.MVCCDelete(batch, nil, hardStateKey, roachpb.ZeroTimestamp, nil)
if err != nil {
return 0, err
}
} else {
err := engine.MVCCPut(batch, nil, hardStateKey, roachpb.ZeroTimestamp, *hardState, nil)
if err != nil {
return 0, err
}
}
// Read the leader lease.
lease, err := loadLeaderLease(batch, desc.RangeID)
if err != nil {
return 0, err
}
// Load updated range stats. The local newStats variable will be assigned
// to r.stats after the batch commits.
newStats, err := newRangeStats(desc.RangeID, batch)
if err != nil {
return 0, err
}
// The next line sets the persisted last index to the last applied index.
// This is not a correctness issue, but means that we may have just
// transferred some entries we're about to re-request from the leader and
// overwrite.
// However, raft.MultiNode currently expects this behaviour, and the
// performance implications are not likely to be drastic. If our feelings
// about this ever change, we can add a LastIndex field to
// raftpb.SnapshotMetadata.
if err := setLastIndex(batch, rangeID, snap.Metadata.Index); err != nil {
return 0, err
}
batch.Defer(func() {
// Update the range stats.
r.stats.Replace(newStats)
r.mu.Lock()
// As outlined above, last and applied index are the same after applying
// the snapshot.
r.mu.appliedIndex = snap.Metadata.Index
r.mu.leaderLease = lease
r.mu.Unlock()
// Update other fields which are uninitialized or need updating.
// This may not happen if the system config has not yet been loaded.
// While config update will correctly set the fields, there is no order
// guarantee in ApplySnapshot.
// TODO: should go through the standard store lock when adding a replica.
if err := r.updateRangeInfo(&desc); err != nil {
panic(err)
}
// Update the range descriptor. This is done last as this is the step that
// makes the Replica visible in the Store.
if err := r.setDesc(&desc); err != nil {
panic(err)
}
})
return snap.Metadata.Index, nil
}
// splitTrigger is called on a successful commit of an AdminSplit
// transaction. It copies the response cache for the new range and
// recomputes stats for both the existing, updated range and the new
// range.
func (r *Range) splitTrigger(batch engine.Engine, split *proto.SplitTrigger) error {
if !bytes.Equal(r.Desc().StartKey, split.UpdatedDesc.StartKey) ||
!bytes.Equal(r.Desc().EndKey, split.NewDesc.EndKey) {
return util.Errorf("range does not match splits: (%s-%s) + (%s-%s) != %s",
split.UpdatedDesc.StartKey, split.UpdatedDesc.EndKey,
split.NewDesc.StartKey, split.NewDesc.EndKey, r)
}
// Copy the GC metadata.
gcMeta, err := r.GetGCMetadata()
if err != nil {
return util.Errorf("unable to fetch GC metadata: %s", err)
}
if err := engine.MVCCPutProto(batch, nil, keys.RangeGCMetadataKey(split.NewDesc.RaftID), proto.ZeroTimestamp, nil, gcMeta); err != nil {
return util.Errorf("unable to copy GC metadata: %s", err)
}
// Copy the last verification timestamp.
verifyTS, err := r.GetLastVerificationTimestamp()
if err != nil {
return util.Errorf("unable to fetch last verification timestamp: %s", err)
}
if err := engine.MVCCPutProto(batch, nil, keys.RangeLastVerificationTimestampKey(split.NewDesc.RaftID), proto.ZeroTimestamp, nil, &verifyTS); err != nil {
return util.Errorf("unable to copy last verification timestamp: %s", err)
}
// Compute stats for updated range.
now := r.rm.Clock().Timestamp()
iter := newRangeDataIterator(&split.UpdatedDesc, batch)
ms, err := engine.MVCCComputeStats(iter, now.WallTime)
iter.Close()
if err != nil {
return util.Errorf("unable to compute stats for updated range after split: %s", err)
}
if err := r.stats.SetMVCCStats(batch, ms); err != nil {
return util.Errorf("unable to write MVCC stats: %s", err)
}
// Initialize the new range's response cache by copying the original's.
if err = r.respCache.CopyInto(batch, split.NewDesc.RaftID); err != nil {
return util.Errorf("unable to copy response cache to new split range: %s", err)
}
// Add the new split range to the store. This step atomically
// updates the EndKey of the updated range and also adds the
// new range to the store's range map.
newRng, err := NewRange(&split.NewDesc, r.rm)
if err != nil {
return err
}
// Compute stats for new range.
iter = newRangeDataIterator(&split.NewDesc, batch)
ms, err = engine.MVCCComputeStats(iter, now.WallTime)
iter.Close()
if err != nil {
return util.Errorf("unable to compute stats for new range after split: %s", err)
}
if err = newRng.stats.SetMVCCStats(batch, ms); err != nil {
return util.Errorf("unable to write MVCC stats: %s", err)
}
// Copy the timestamp cache into the new range.
r.Lock()
r.tsCache.MergeInto(newRng.tsCache, true /* clear */)
r.Unlock()
batch.Defer(func() {
if err := r.rm.SplitRange(r, newRng); err != nil {
// Our in-memory state has diverged from the on-disk state.
log.Fatalf("failed to update Store after split: %s", err)
}
})
return nil
}