On 10/11/11 4:18 AM, "Steve Loughran" <[email protected]> wrote:
>On 10/10/11 19:57, Scott Carey wrote: > >> What JRE (6 update ?) is planned to be used when testing 0.23 at scale? >> Should JRE 7u2 also be tested? Both a new update to JRE 6 and 7 is due >> out very soon. 0.23 will be code complete after that. If I had enough >> resources and time, I'd test both the latest JRE 6 and JRE 7. > >Makes sense. Ideally anyone planning to move to 0.23 should bring up >some kind of cluster running that code on their chosen JVM, with their >own algorithms, just to see what the outcome is. Too bad nobody has a >large idle cluster with data they don't care about. EMC have just >announced one though, and HortonWorks and Cloudera will also have >clusters. That doesn't mean you shouldn't test on your own >hardware/OS/network/application setup. > > >> >> A performance regression for Hadoop's pure java CRC32 happened in a >>recent >> JRE6 update, and a bug was filed, and they fixed it and now include that >> algorithm in their test suite. JVM releases don't include whole stacks, >> but someone could engage the OpenJDK developers to find out what kind of >> contributions OpenJDK can accept for test code -- I'm not sure how >> compatible it is with Apache. >> >>http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2011-July/005 >>97 >> 1.html >> >>http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2011-Septembe >>r/ >> 006289.html > >Thanks, Scott, that is really informative FYI, Java 7u1 fixes the lucene related loop predicate bugs: http://lucene.apache.org/solr/#26+October+2011+-+Java+7u1+fixes+index+corru ption+and+crash+bugs+in+Apache+Lucene+Core+and+Apache+Solr Java 6u29 fixes them as well (they are only exposed in Java 6 if you used +AggressiveOpts or the equivalent). 7u2 is relatively far along: http://jdk7.java.net/download.html > >> >>> >>> In the meantime, even if Oracle say Java6 is EOL, if people pay money >>>to >>> keep it alive -and they will have to in any project you don't want to >>> have to requalify for java7- then it may keep going for longer, except >>> the updates won't be so widely available. >> >> You can always keep running on the old JVM with the old version of >>Hadoop >> you have had in your cluster, but if you upgrade Hadoop to a new >>version, >> you might as well upgrade your JVM at the same time and pay the testing >> cost once. > >I have mixed feelings about that. You may be introducing too many >variables at once.
