Do not get lock when saving snapshot (#461)

Do not get lock when saving snapshot and increase entries before snapshot

Author: purplefox

cluster/dragon/shard_odsm.go

@@ -328,8 +328,6 @@ func (s *ShardOnDiskStateMachine) PrepareSnapshot() (interface{}, error) {
 }
 
 func (s *ShardOnDiskStateMachine) SaveSnapshot(i interface{}, writer io.Writer, _ <-chan struct{}) error {
-	s.lock.Lock()
-	defer s.lock.Unlock()
 	log.Debugf("data shard %d saving snapshot", s.shardID)
 	snapshot, ok := i.(*pebble.Snapshot)
 	if !ok {

push/source/source.go

@@ -243,7 +243,7 @@ func (s *Source) consumerError(err error, clientError bool) {
 		return
 		//panic("Got consumer error but souce is not started")
 	}
-	log.Errorf("Failure in consumer, source will be stopped: %+v. ", err)
+	log.Errorf("Failure in consumer, source %s.%s will be stopped: %+v", s.sourceInfo.SchemaName, s.sourceInfo.Name, err)
 	if err2 := s.stop(); err2 != nil {
 		return
 	}