JetStream. "Queue group" feature with pull subscribers

[ruslan528]

Can we distribute mesages from one subject to dynamic pool of applications with pull readers? Now we do that using one push consumer with "Deliver Queue Group" specified and one subscriber with such group in each app. So message processed only in one available application. Can we do that using pull subscribers? It's important that:

1. Every message must be processed as soon as possible
2. No matter what app do that processing
3. Only one app must process one concrete message
4. We can have one, two or more apps in a moment.
   In Kafka it realized with "consumer group" feature.

[derekcollison]

Yes pull consumers will allow that behavior.

[ruslan528]

Please, describe in short hand how to do that with pull subscribers.

Or you meaning that in future? You wrote this comment nats-io/jetstream#103 (comment) 4 years ago. Is it stil not implemented? :(

[derekcollison]

You can add pull consumers for all messages or any subset that can be expressed by a subject (wildcard). You then run as many application binding to the same consumer.

When scaling back down we recommend draining the subscriptions.

https://natsbyexample.com/examples/jetstream/pull-consumer/go