Refresh coordinator in consumer group

[muirdm]

Now if the consumer group gets ErrNotCoordinatorForConsumer when
starting to consume it will refresh the coordinator instead of trying
to use the wrong/stale coordinator forever.

[varun06]

Looks good. But consumer group functionality has very few tests :(

[muirdm]

Yes, I think we need tests that run against a multi-node cluster so we can test all the interesting things that happen when you restart nodes. I would be happy to add coverage to that type of test suite, but I'm not prepared to set all that up right now.

[bai]

I could help with multi-node cluster infra via docker-compose on Monday.

[varun06]

@bai I am trying to setup one locally on my mac, man it is hard on mac, specially SR and REST-PROXY part.

[bai]

@varun06 Curious - have you checked https://github.com/confluentinc/cp-docker-images/tree/master/examples? Those are working ok for me locally generally.

[varun06]

@bai I am using same, but their cluster ones don't have Schema registry and rest proxy.

[bai]

Oh well ¯_(ツ)_/¯ I'll spare some time on Monday to unblock this.

[varun06]

I am making some advances, if I can get it going today, I will send docker-compose.yml your way.

[varun06]

@bai https://gist.github.com/varun06/7346ed726a1531022a85fd162af4e402

This is a working copy on my local mac machine. I had some trouble making multi zk works, so I only have 1 zk and 3 kafka brokers with SR and Kafka-rest. hope it will be helpful.

[varun06]

@muirrn What's the status on this?

[muirdm]

If I remember, I was waiting for a multi-node test suite to be in place so I could add my test coverage. Are there tests now that use your docker compose setup?

[varun06]

I believe not, @bai what do we need to do for a multi node setup?

[dnwe]

@muirrn happened to see this old PR and I think the fix from this PR was eventually covered by a change in PR #1231 so this one can probably be closed now

[muirdm]

@dnwe Thanks. It does seem to address the same issue, although hard to be sure of anything without multinode tests.

[dnwe]

What do you mean by multi node tests? Afaik the vagrant cluster that is spun up for Travis is a 3 broker kafka cluster?

[muirdm]

Afaik the vagrant cluster that is spun up for Travis is a 3 broker kafka cluster

Oh, if there are tests that exercise multi-node cluster behavior then that is great. I assumed there wasn't any based on this PR still being in limbo.