Method Drain

nats.go:5066–5077

Drain will remove interest but continue callbacks until all messages have been processed. For a JetStream subscription, if the library has created the JetStream consumer, the library will send a DeleteConsumer request to the server when the drain operation completes. If a failure occurs when deleti

()

// ensure that the consumer is not created by the library, which means
// create the consumer with AddConsumer and bind to this consumer.
func (s *Subscription) Drain() error {
	if s == nil {
		return ErrBadSubscription
	}
	s.mu.Lock()
	conn := s.conn
	s.mu.Unlock()
	if conn == nil {
		return ErrBadSubscription
	}
	return conn.unsubscribe(s, 0, true)
}

// IsDraining returns a boolean indicating whether the subscription
// is being drained.