joseluisll opened a new pull request, #8724: URL: https://github.com/apache/hadoop/pull/8724
### Description of PR https://issues.apache.org/jira/browse/HADOOP-19987 `getHAServiceStateWithTimeout` catches `RejectedExecutionException` to fall back to the active NameNode, but that fallback is unreachable: the probing pool was a `BlockingThreadPoolExecutorService`, whose `submit()` blocks on a semaphore instead of rejecting. A caller that should have been shed onto the active NN is parked instead — while holding the provider's monitor, since the probe runs inside the `synchronized changeProxy()`. Latent today: the only production caller is inside `changeProxy()`, so there is at most one probe in flight per provider. Reaching saturation needs `dfs.client.failover.namenode.ha-state.probe.timeout` set above its `0` default plus probes that don't return on interrupt — but when it happens the monitor is held forever. Fix: use a plain `ThreadPoolExecutor` with the same shape (4 threads, 128-deep queue, 10s idle timeout, daemon threads) and the default `AbortPolicy`. Capacity is unchanged at 132; the field type widens to `ExecutorService`. Thread names keep the `nn-ha-state-probing-pool<N>-t<M>` shape, with the per-thread counter now starting at `t0` and `<N>` counting probing pools alone. ### How was this patch tested? Two new tests in `TestObserverReadProxyProvider`, each running the call under test on its own thread with an explicit deadline so a hang names the stuck call: - `testProbingPoolRejectsOnceSaturated` — `submit()` past capacity throws instead of blocking. - `testFallsBackToActiveWhenProbingPoolSaturated` — the HA-state probe returns and falls back to the active NN. Both fail against the old pool, blocking for the full 20s deadline. Full CI green on the fork (`common`, `hdfs - other`, `hdfs - slow`, `hdfs-rbf`, `mr`, `other`, `yarn-server-rm` on Java 17; build-only on Java 21 and 25): https://github.com/joseluisll/hadoop/actions/runs/34147776162 `common` needed a rerun for `TestZKDelegationTokenSecretManager#testNodesLoadedAfterRestart`, an unrelated pre-existing flake in `hadoop-common`; this patch only touches `hadoop-hdfs-client`. ### For code changes: - [x] Does the title of this PR start with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')? - [ ] Object storage: Have the integration tests been executed and the endpoint declared according to the connector-specific documentation? - [ ] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under [ASF 2.0](http://www.apache.org/legal/resolved.html#category-a)? - [ ] If applicable, have you updated the `LICENSE`, `LICENSE-binary`, `NOTICE-binary` files? ### AI Tooling Contains content generated by Claude Code. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
