Silence WARNs during rebalancing
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- Dominant language
- Java
- Stars
- 373
- Forks
- 61
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Description
On decaton 6, observing the following WARNs, when
- cooperating rebalancing is ON
- a node joins the consumer group
```
com.linecorp.decaton.processor.runtime.internal.CommitManager:131
Offset commit failed asynchronously
org.apache.kafka.common.errors.RebalanceInProgressException: Offset commit cannot be completed since the consumer is undergoing a rebalance for auto partition assignment. You can try completing the rebalance by calling poll() and then retry the operation.
```
I don't think the end-user needs to know about this, since `poll()` is soon going to be called again in `ProcessorSubscription.consumeLoop`
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start in CommitManager around line 131 and trace how ProcessorSubscription.consumeLoop handles polling during cooperative rebalancing. Reproduce the described node-join scenario and verify that the expected RebalanceInProgressException no longer produces a user-facing WARN while other asynchronous commit failures remain visible.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java, kafka
- Domain
- stream-processing
- Issue type
- Bug
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100