storage/remote/queue_manager.go
func (s *shards) enqueue(ref uint64, sample prompb.TimeSeries) bool {
	s.mtx.RLock()
	defer s.mtx.RUnlock()

	select {
	case <-s.softShutdown:
		return false
	default:
	}

	shard := uint64(ref) % uint64(len(s.queues))
	select {
	case <-s.softShutdown:
		return false
	case s.queues[shard] <- sample:
		return true
	}
}
func (s *shards) enqueue(ref uint64, sample prompb.TimeSeries) bool {
	s.mtx.RLock()
	defer s.mtx.RUnlock()

	select {
	case <-s.softShutdown:
		return false
	default:
	}

	shard := uint64(ref) % uint64(len(s.queues))
	select {
	case <-s.softShutdown:
		return false
	case s.queues[shard] <- sample:
		return true
	}
}
func ( s * shards ) enqueue ( ref uint64 , sample prompb . TimeSeries ) bool { s . mtx . RLock ( ) defer s . mtx . RUnlock ( ) select { case <- s . softShutdown : return false default : } shard := uint64 ( ref ) % uint64 ( len ( s . queues ) ) select { case <- s . softShutdown : return false case s . queues [ shard ] <- sample : return true } }
// enqueue a sample.  If we are currently in the process of shutting down or resharding,
// will return false; in this case, you should back off and retry.
enqueue a sample . If we are currently in the process of shutting down or resharding will return false ; in this case you should back off and retry .