Hi everyone, I would like to discuss a new Apache Flink 2.3.1 patch release. I can volunteer as the release manager.
Since the Apache Flink 2.3.0 release on June 25, 2026 [1], the release-2.3 branch has accumulated these notable fixes: - FLINK-39964 [2] - Restored jobs can produce checkpoints that cannot be recovered. - FLINK-40475 [3] - Event-time processing can stall. - FLINK-40335 [4] - Hybrid Shuffle jobs can fail because of corrupted index files. - FLINK-40539 [5] - SQL Gateway responses can expose sensitive configuration values. - FLINK-40727 [6] - Internal SSL connections can fail hostname verification. The branch comparison [7] and Jira 2.3.1 issue list [8] provide the full scope. Before cutting a release candidate, please advise whether these items need action for this release: - FLINK-38770 [9] - Kubernetes Operator autoscaling can fail in Application Mode. - FLINK-40648 [10] - Prometheus can drop all metrics from a Flink process. - FLINK-40883 [11] - Some SQL OVER window queries can fail. - FLINK-40657 [12][13] - Source jobs can leak memory over time. - FLINK-39924 [14] - TaskManagers can be OOM-killed despite having unused memory. - CI [15] - AdaptiveScheduler / Test (module: misc): two Kubernetes tests errored, including EnvSecretsDecoratorTest.testWhetherPodOrContainerIsDecorated. Please let me know if there are any other issues we should consider before cutting a release candidate. Best, Rui Fan [1] https://flink.apache.org/2026/06/25/apache-flink-2.3.0-release-announcement/ [2] https://issues.apache.org/jira/browse/FLINK-39964 [3] https://issues.apache.org/jira/browse/FLINK-40475 [4] https://issues.apache.org/jira/browse/FLINK-40335 [5] https://issues.apache.org/jira/browse/FLINK-40539 [6] https://issues.apache.org/jira/browse/FLINK-40727 [7] https://github.com/apache/flink/compare/release-2.3.0...release-2.3 [8] https://issues.apache.org/jira/issues/?jql=project%20%3D%20FLINK%20AND%20fixVersion%20%3D%202.3.1 [9] https://issues.apache.org/jira/browse/FLINK-38770 [10] https://issues.apache.org/jira/browse/FLINK-40648 [11] https://issues.apache.org/jira/browse/FLINK-40883 [12] https://issues.apache.org/jira/browse/FLINK-40657 [13] https://github.com/apache/flink/pull/29387 [14] https://issues.apache.org/jira/browse/FLINK-39924 [15] https://github.com/apache/flink/actions/runs/38016043060/job/114116637876
