Michael Smith has posted comments on this change. ( http://gerrit.cloudera.org:8080/19863 )
Change subject: IMPALA-11941: Support Java 17 in Impala ...................................................................... Patch Set 27: > Patch Set 26: > > (1 comment) > > > I also added metrics and compared jamm vs ehcache for a few > > operations after running > https://github.com/apache/impala/blob/master/tests/custom_cluster/test_local_catalog.py#L472-L518. > > They're almost identical: > > > > Jamm: > > catalog.cache.entry-99th-size 14.10 KB 99th percentile size of > > Impalad Catalog cache entries. > > catalog.cache.entry-median-size 376.00 B Median size of Impalad > > Catalog cache entries. > > catalog.cache.entry-stddev-size 2648.229397 Standard deviation for > > size of Impalad Catalog cache entries. > > > > Ehcache: > > catalog.cache.entry-99th-size 14.10 KB 99th percentile size of > > Impalad Catalog cache entries. > > catalog.cache.entry-median-size 376.00 B Median size of Impalad > > Catalog cache entries. > > catalog.cache.entry-stddev-size 2639.141904 Standard deviation for > > size of Impalad Catalog cache entries. > > > > I can push up the additional changes to allow switching back to > > ehcache and adding these metrics (not sure stddev is worth it when > > 99th percentile is more readable). > > I agree that stddev might not be very useful. median and 99th percentile are > useful. Is max useful? max feels like marginal additional utility. It might be useful if something really weird's going on with memory use in the cache, but it has a limit and 99th percentile would likely give a similar signal. -- To view, visit http://gerrit.cloudera.org:8080/19863 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ic378896f572e030a3a019646a96a32a07866a737 Gerrit-Change-Number: 19863 Gerrit-PatchSet: 27 Gerrit-Owner: Michael Smith <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Laszlo Gaal <[email protected]> Gerrit-Reviewer: Michael Smith <[email protected]> Gerrit-Reviewer: Quanlong Huang <[email protected]> Gerrit-Comment-Date: Thu, 22 Jun 2023 16:29:30 +0000 Gerrit-HasComments: No
