pack-objects cache misses unexpectedly since Gitlab 15.11
Hey there,
we have upgraded to the most recent Gitlab 15.11.0 and apparently our pack-objects cache does not work as it did before. The cache is filled much more rapidly and requires more space now. After some manual testing, we found that the cache content would not be reused in certain scenarios in which we would expect it to be. This leads to more data being stored in the cache and higher CPU usage on the server.
Our findings:
- The cached contents are NOT reused if two users start identical fetch requests.
- The cached contents are NOT reused if se same user starts identical fetch requests on different machines.
- The cached contents ARE reused if the same user starts indentical fetch requests on the same machine.
This is not expected behaviour, is it? It seemed to work fine on previous 15.10.3.
We have noted the change to min_occurrences
, but don't think it's the reason. We had the cache enabled before and the previous behaviour was equal to "0". We had it at "1" and also tried "0" to get back to old behaviour. That changed observed behaviour only in the expected way (= the scenario with cache hits would need one more request to start caching).
We would appreciate any feedback on this. Regards Daniel