[10.2.x] Backport #13234: Fix LRU RAM cache seen filter never engaging below 100% full#13317
Open
phongn wants to merge 1 commit into
Open
Conversation
…13234) proxy.config.cache.ram_cache.use_seen_filter values above 1 are documented to turn on the seen filter once the cache is (N-1)/N full (2 = 50%, 3 = 67%, ... 9 = 90%). The threshold was written as bytes >= max_bytes * (1 - (1 / N)) with N an int, so 1 / N is integer division and evaluates to 0 for every N > 1; the test became bytes >= max_bytes and the filter only engaged when completely full. A scan could therefore pollute a half-full cache. Rewrite the comparison as bytes * N >= max_bytes * (N - 1), which is exact in integer arithmetic and overflow-safe at realistic cache sizes. Add ram_cache_lru_seen_filter, which fails on the old form (20/20 unseen keys admitted at 60% full) and passes on the fix (0/20). Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Contributor
|
[approve ci autest 2] |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This is a cherry-pick backport of the fix resolving the issue where the LRU RAM cache seen filter never engaged below 100% full, originally in #13234 (see that PR for details).