[SOLR-17277] Circuit Breakers should support a "Warn-only" mode

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: main (10.0)
• Fix Version/s: main (10.0), 9.7
• Component/s: Circuit Breakers
• Labels: newdev
• Assignee: Jason Gerlowski
• Reporter: Jason Gerlowski
• Created: 06/May/24 17:06
• Updated: 25/Oct/24 17:18
• Resolved: 28/May/24 16:42

Description

The threshold values used when configuring Circuit Breakers are incredibly important. Identifying when load begins to get "dangerous" is tricky: too stringent and users will get 429s unnecessarily, too lax and the circuit breakers won't be effective at preventing crashes.

Conservative users may wish to evaluate potential thresholds without actually blocking traffic. Could Circuit Breakers offer some sort of "Dry Run" capability - where a request that would otherwise have been blocked merely logs a message? This would allow users to get feedback on their thresholds before they actually start sending CB-based 429s to users.

Issue Links

• links to: GitHub Pull Request #2476