[CASSANDRA-9872] only check KeyCache when it is enabled

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.1.10, 2.2.2, 3.0 beta 2
• Labels: cache metrics
• Severity: Low
• Assignee: Chris Burroughs
• Reporter: Chris Burroughs

Authors

Chris Burroughs

Reviewers

Robert Stupp

• Created: 22/Jul/15 20:33
• Updated: 16/Apr/19 09:31
• Resolved: 31/Aug/15 09:09

Description

If the KeyCache exists (because at least one column family is using it) we currenlty check the key cache even for requests to column families where the key cache is disabled. I think it would be better to only check the cache if entries could be there.

• This will align the key cache with how the row cache behaves.
• This makes the key cache metrics much more useful. For example, 'requests' becomes 'requests to things that could be in the key cache' and not just 'total requests'.
• This migh be a micro-optimization saving a few metric update.

Issue Links

• links to: Cassci (CI)