sgup432 commented on issue #14028: URL: https://github.com/apache/lucene/issues/14028#issuecomment-2617663032
@kkewwei Great to see the improvement by changing the skip factor. I see there have been many discussions around finding the right value for `skip_factor` ([here](https://issues.apache.org/jira/browse/LUCENE-9002) and [here](https://github.com/apache/lucene/issues/11081)), mostly the concern being that caching large query clauses(as per their cost and eventually size) may not make much sense, considering they will make the overall query slow due to cache overhead(locks, eviction). As per your experiment, I see query cache was heavily underutilized and increasing skip factor caused more queries to be cached. However, the cache didn't reach the limit(3gb) and I assume there were no evictions. I wonder what happens when you start observing more evictions? I suspect the overall gains you got by increasing `skip_factor` would eventually fade away due to the overhead(caused by evictions/locks). Have you started noticing any evictions from the cache yet? But I certainly believe we should have the ability to set `skip_factor` dynamically within cache by having a simple setter method? Looks like a harmless change to me. >it will also not be cached because of the skipCacheFactor(100,000,000 / skipCacheFactor > 500). I believe you meant `500 / skipCacheFactor > 100,000,000` and not the other way around. -- 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: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
