0xffff-zhiyan opened a new pull request, #20481: URL: https://github.com/apache/kafka/pull/20481
This PR implements [KIP-1207](https://cwiki.apache.org/confluence/display/KAFKA/KIP-1207%3A+Fix+anomaly+of+JMX+metrics+RequestHandlerAvgIdlePercent+in+kraft+combined+mode) This PR implements a global shared thread counter mechanism to properly calculate the `RequestHandlerAvgIdlePercent` metric across all `KafkaRequestHandlerPool` instances within the same JVM process in Kraft combined mode. This ensures accurate idle percentage calculations, especially in combined KRaft mode where both broker and controller request handler pools coexist. Previously, each `KafkaRequestHandlerPool` calculated idle percentages independently using only its own thread count as the denominator. In combined KRaft mode, this led to: - Inaccurate aggregate idle percentage calculations - Potential metric values exceeding 100% (values > 1.0) - Inconsistent behavior between isolated and combined modes **Core Changes** 1. Global Thread Counter: `Added sharedAggregateTotalThreads` as a global AtomicInteger in `KafkaRequestHandlerPool ` 2. Modified KafkaRequestHandler to calculate two idle metrics: Per-pool metric: Uses local thread count (totalHandlerThreads.get) Aggregate metric: Uses global thread count (sharedAggregateTotalThreads.get) **Test** Added perPoolIdleMeter parameter to all KafkaRequestHandler instantiations Added global counter initialization: KafkaRequestHandlerPool.sharedAggregateTotalThreads.set(1) in test class setup Added new unit test verifies: 1.Global counter accumulation across multiple pools 2.Proper idle percentage calculation within [0, 1.05] range 3.Counter cleanup after pool shutdown POC locally: <img width="648" height="270" alt="Screenshot 2025-09-04 at 15 32 32" src="https://github.com/user-attachments/assets/6fe03ff5-3cb2-4a6d-af2b-097017c0aadd"; /> <img width="651" height="275" alt="Screenshot 2025-09-04 at 15 34 26" src="https://github.com/user-attachments/assets/b64a0713-6c99-4997-bebd-f93c634f2242"; /> -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
