[CASSJAVA-41] Reduce lock held duration in ConcurrencyLimitingRequestThrottler

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 4.19.0
• Assignee: Jason Koch
• Reporter: Andy Tolbert

Authors

Jason Koch

• Created: 13/Sep/24 15:05
• Updated: 06/Nov/24 23:14
• Resolved: 13/Sep/24 16:39

Description

This JIRA covers the java driver PR: https://github.com/apache/cassandra-java-driver/pull/1957

via: jasonkoch:

It might take some (small) time for callback handling when the throttler request proceeds to submission.

Before this change, the throttler proceed request will happen while holding the lock, preventing other tasks from proceeding when there is spare capacity and even preventing tasks from enqueuing until the callback completes.

By tracking the expected outcome, we can perform the callback outside of the lock. This means that request registration and submission can proceed even when a long callback is being processed.

Issue Links

• links to: GitHub Pull Request #1957