cshuo opened a new pull request, #20031: URL: https://github.com/apache/hudi/pull/20031
### Describe the issue this Pull Request addresses Related to #19902. Instant-time requests return `null` whenever the instant creation executor is busy, even if the requested checkpoint already has an instant. In blocking instant generation mode, creation for the next checkpoint can wait for the previous instant to commit while a slower writer needs that existing instant to finish its checkpoint. This circular wait can stall the job until timeout. ### Summary and Changelog - Look up the existing checkpoint-to-instant mapping before checking whether the creation executor is busy. Submit creation only when the mapping is absent and the executor is idle. - Add a regression test verifying that an existing instant remains available while another checkpoint's creation is blocked. Validation: 9 targeted tests passed with JDK 17 and the Flink 2.2 profile, using a Maven reactor build with `-am`. These cover the new regression, blocked-creation polling, executor task accounting, and correspondent polling/error handling. `git diff --check` also passed. ### Impact Allows writers to retrieve existing instants while another instant is being created, preventing this circular wait. No public API or configuration changes. ### Risk Level Low. The change only adjusts the lookup and submission condition; the worker-side mapping recheck and single-threaded creation executor are retained. The regression test and existing polling tests pass. ### Documentation Update None. ### Contributor's checklist - [ ] Read through [contributor's guide](https://hudi.apache.org/contribute/how-to-contribute) - [x] Enough context is provided in the sections above - [x] Adequate tests were added if 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
