Zakelly opened a new pull request, #25968: URL: https://github.com/apache/flink/pull/25968
## What is the purpose of the change In [FLINK-37089](https://issues.apache.org/jira/browse/FLINK-37089), we resolved the deadlock of derived requests waiting on draining current request, when user call `asyncProcessWithKey`. However, we also found the timer may also suffer from this problem. Thus I suggest a buffer overdraft for all those derived requests, to resolve the deadlock when there is a single hotspot key and all the requests queue in line while there comes a derived with same key, that cannot properly queue in a full buffer. ## Brief change log - Remove `BatchCallbackRunner`, as it is problematic by only leaving one mail in the mailbox, which may cause deadlock when `yield()`. - Add overdraft param for the `seizeCapacity` method of buffer. ## Verifying this change This change added tests `AsyncExecutionControllerTest#testSyncPointWithOverdraft` ## Does this pull request potentially affect one of the following parts: - Dependencies (does it add or upgrade a dependency): no - The public API, i.e., is any changed class annotated with `@Public(Evolving)`: no - The serializers: no - The runtime per-record code paths (performance sensitive): yes - Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no - The S3 file system connector: no ## Documentation - Does this pull request introduce a new feature? no - If yes, how is the feature documented? not applicable -- 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. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
