Joe McDonnell has posted comments on this change. ( http://gerrit.cloudera.org:8080/19863 )
Change subject: IMPALA-11941: Support Java 17 in Impala ...................................................................... Patch Set 23: > > Patch Set 23: > > > > Do we want a way to fall back to ehcache sizeof? In other words, > if we run with jamm and we suspect there is an issue, we could > restart with the option to use the old ehcache implementation. This > option is not useful for Java 17 and it would still need the > add-opens. jamm would be the default. > > > > I'm trying to think about ways to test. Here are random thoughts: > > 1. Start catalog, load a few tables, compare the size > measurements from jamm to what we get with ehcache. > > 2. Start catalog, take a measurement, load a text table (e.g. > tpcds.store_sales), take a measurement, then load the parquet > equivalent (tpcds_parquet.store_sales), take another measurement. > In theory, the size of the metadata for the text table should be > close to the same size as the metadata for the parquet table? > > I don't know if those metrics are easily accessible. > > > > It's not clear what level of testing we need for the accuracy of > jamm vs ehcache. Then again, we didn't put ehcache through that > level of scrutiny. > > That's a reasonable fallback, and would make running some of those > tests easier. I looked back at the original change that introduced ehcache (https://github.com/apache/impala/commit/078232112469c238d5332453627eb37dcb10eb97), and CatalogdMetaProviderTest::testWeights() sets some bounds on functional.alltypes, so that is a basic sanity check. -- 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: 23 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: Tue, 20 Jun 2023 21:30:52 +0000 Gerrit-HasComments: No
