showuon commented on pull request #9733: URL: https://github.com/apache/kafka/pull/9733#issuecomment-748849742
@mjsax , as mentioned in https://github.com/apache/kafka/pull/9690#issuecomment-747243284, I've updated the commit. What my change is: 1. Before my change, when we started a stream with the other one is running, we'll just `waitForRunning` for both streams. But we actually expect more than 1 rebalancing here (unstable + stable assignments), that would make us run the following tests under the wrong stream state. For example: When stream1 started, it might go through ``` [CREATED -> REBALANCING], [REBALANCING -> RUNNING](unstable), [RUNNING -> REBALANCING], [REBALANCING -> RUNNING](stable) ``` So, if we only `waitForRunning`, it might be just after the unstable rebalancing. Though we have `waitForStableAssignment`, it still doesn't guarantee it already completed the stable rebalacing. That is, we need to wait for the "specific number" of `[REBALANCING -> RUNNING]` state transition so that we can make sure it completes all necessary rebalancing. And the "specific number" can be counted by the `onAssignmentComplete` callback. Note: I only `waitForNumRebalancingToRunning` for the new started stream because I found sometimes if the stream runs fast enough, the already running stream might not have the expected number of `[REBALANCING -> RUNNING]` state transition. The reason is this line: ``` [appDir2-StreamThread-1] State transition from PARTITIONS_ASSIGNED to PARTITIONS_ASSIGNED ``` Basically, The already running stream thread should have the state change: `[RUNNING to PARTITIONS_REVOKED]`, `[PARTITIONS_REVOKED to PARTITIONS_ASSIGNED](unstable)`, `[PARTITIONS_ASSIGNED to RUNNING] + [RUNNING to PARTITIONS_ASSIGNED](stable)`, `[PARTITIONS_ASSIGNED to RUNNING]`. Because it needs one more PARTITIONS_REVOKED step, it might be under 2 PARTITIONS_ASSIGNED at the same time. 2. Fail the test when there are too many exception thrown or unexpected exception thrown by the `hasUnexpectedError` flag. Thank you. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
