I often get the error nats: no heartbeat received

[VuongUranus]

Observed behavior

I often get the error no heartbeat received. Why do I get this error, where have I misconfigured?
When I get this error it seems like my pull consumer has been deleted, I don't know the reason but it seems to be due to exceeding the time configured in the InactiveThreshold attribute configured in the consumer config.

func  ContinuousPolling(cons jetstream.Consumer, f func([]byte)) (jetstream.MessagesContext, error) {
	iter, err := cons.Messages()
	if err != nil {
		log.Error().Msgf("Error when get message from NATS: %v", err)
		return nil, err
	}
	go func() {
		for {
			msg, err := iter.Next()
			if err != nil {
				if errors.Is(err, jetstream.ErrMsgIteratorClosed) || errors.Is(err, jetstream.ErrConsumerDeleted) {
					return
				}

				log.Error().Msgf("Error when consume message. Reson: %v",  err)
				continue
			}
			go f(msg.Data())
			msg.Ack()
		}
	}()

	return iter, nil
}

func setDefaultConsumerConfig(subjects []string, consumerName ...string) jetstream.ConsumerConfig {
	name := ""
	if len(consumerName) > 0 {
		name = consumerName[0]
	}

	return jetstream.ConsumerConfig{
		Name:              name,
		DeliverPolicy:     jetstream.DeliverNewPolicy,
		FilterSubjects:    subjects,
		AckPolicy:         jetstream.AckAllPolicy,
		Replicas:          1,
		InactiveThreshold: 1 * time.Minute,
	}
}

Expected behavior

Please explain to me and avoid this situation again.

Server and client version

nats-server version: 2.10.12

Host environment

No response

Steps to reproduce

No response

[Jarema]

Hey!

What we don't see here, is the context in which both provided functions are called. Could you please share it?

Inactive Threshold kicks in when there is noone listening for messages from a consumer (so, no Fetch or Messages active).

This means it can happen for example if there is a long pause between creating a consumer and consuming its messages, or longer than a minute app downtime (the app that is consuming).

Moving the issue to the nats.go repo, as it's probably a client side discussion unless we find any issue.