BackendArchitectX opened a new pull request, #19915: URL: https://github.com/apache/pinot/pull/19915
## Summary Fixes #19852. The replica-group instance selector previously used `Set<String>` as a `HashMap` key when tracking unavailable instances. Server instance names with similar numeric suffixes could produce excessive hash collisions and slow down routing-map updates. This change: - Introduces an immutable `InstanceSetKey` with sorted instance names and improved hashing. - Updates unavailable-instance lookups to use the new key. - Adds regression tests for hash collisions, routing isolation, recovery and hash distribution. ## Validation - `InstanceSelectorTest`: 95 tests passed, 0 failures. - Maven reactor build: 29 modules successful. - Targeted Checkstyle: 0 violations. - Git whitespace validation passed. ## Notes The hash-distribution test covers 100,000 instance combinations. A production-scale routing rebuild benchmark has not yet been performed. Assisted-by: GPT-6 (ChatGPT). -- 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]
