Update: The ByteBuffer pread backport is under reviewing now. https://github.com/apache/hadoop/pull/997
As Hadoop team said, the Hadoop 2.8 will be EOL soon, so our HDFS team will backport this patch to branch-2 & branch-2.9, we may need to upgrade the hadoop dependencies from 2.8.5 to 2.9.3 in future. Thanks. On Wed, Jun 19, 2019 at 10:41 PM OpenInx <open...@gmail.com> wrote: > Thanks for your reviewing and flaky test checking, Duo. > Will file a separate issue to address your comment if necessary. > > Thanks. > > On Wed, Jun 19, 2019 at 9:55 PM 张铎(Duo Zhang) <palomino...@gmail.com> > wrote: > >> +1 from me. >> >> Left a few comments on github PR, not big problems. And the flaky >> dashboard >> is pretty good. >> >> >> https://builds.apache.org/job/HBASE-Find-Flaky-Tests/job/HBASE-21879/lastSuccessfulBuild/artifact/dashboard.html >> >> >> The TestConnectionImplementation was also failing on master, and was fixed >> after merging back HBASE-21512. >> >> 张铎(Duo Zhang) <palomino...@gmail.com> 于2019年6月18日周二 下午9:48写道： >> >> > Good. Will take a look soon. >> > >> > OpenInx <open...@gmail.com> 于2019年6月18日周二 下午9:41写道： >> > >> >> > Could please open a PR, just like what I have done for HBASE-21512, >> so >> >> that others could have a overall view on the modified code? >> >> >> >> OK, created a PR for this: https://github.com/apache/hbase/pull/320 >> >> Thanks for your suggestion, Duo. >> >> >> >> On Tue, Jun 18, 2019 at 9:24 PM 张铎(Duo Zhang) <palomino...@gmail.com> >> >> wrote: >> >> >> >> > The performance number is great. >> >> > >> >> > Could please open a PR, just like what I have done for HBASE-21512, >> so >> >> that >> >> > others could have a overall view on the modified code? >> >> > >> >> > Thanks. >> >> > >> >> > OpenInx <open...@gmail.com> 于2019年6月18日周二 下午6:58写道： >> >> > >> >> > > BTW, when testing this branch, we found some performance issues >> >> about >> >> > > HDFS Client: >> >> > > 1. we reduced the DFS client's heap allocation from 45% to 27% >> >> > > in HDFS-14535 [1]; >> >> > > 2. we also increased get throughput by 17.8% in disabled block >> cache >> >> > case >> >> > > in HDFS-14541[2]. >> >> > > In theory, it should also helps a lot (especially p99/p999) >> even >> >> if >> >> > RS >> >> > > has a high cacheHitRatio. >> >> > > >> >> > > I think the next HDFS 2.8 release will include those patches, >> they're >> >> > very >> >> > > good points for our >> >> > > HBase performance. >> >> > > >> >> > > [1]. https://issues.apache.org/jira/browse/HDFS-14535 >> >> > > [2]. >> >> > > >> >> > > >> >> > >> >> >> https://issues.apache.org/jira/browse/HDFS-14541?focusedCommentId=16866472&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16866472 >> >> > > >> >> > > Thanks. >> >> > > >> >> > > On Tue, Jun 18, 2019 at 12:05 PM OpenInx <open...@gmail.com> >> wrote: >> >> > > >> >> > > > The HBASE-21879 has lots of changes: 123 files changed, 5833 >> >> > > > insertions(+), 3015 deletions(-). >> >> > > > Currently we developed this issue based on master branch, and >> >> expect to >> >> > > > release it in future HBase3.x. >> >> > > > Of course, if branch-2 want this feature we can do the backport, >> >> should >> >> > > > have some conflicts now but I >> >> > > > don't think it would be hard to fix because I believe the >> branch-2 >> >> > > > shouldn't have so much diff with master now >> >> > > > (at least in read path). >> >> > > > The first priority thing for now, I think it would be merging >> the >> >> > > > HBASE-21879 branch to master branch >> >> > > > before diverging. After that, I can do the backport. >> >> > > > >> >> > > > Thanks for your suggestion, Guanghao ! >> >> > > > >> >> > > > >> >> > > > >> >> > > > On Tue, Jun 18, 2019 at 11:39 AM Guanghao Zhang < >> zghao...@gmail.com >> >> > >> >> > > > wrote: >> >> > > > >> >> > > >> This is a improvement not a new feature? So backport to >> branch-2, >> >> too? >> >> > > >> >> >> > > >> OpenInx <open...@gmail.com> 于2019年6月17日周一 下午2:45写道： >> >> > > >> >> >> > > >> > Dear HBase dev: >> >> > > >> > >> >> > > >> > In HBASE-21879[1], we redesigned the offheap read path: read >> the >> >> > > >> HFileBlock >> >> > > >> > from HDFS to pooled offheap >> >> > > >> > ByteBuffers directly, while before HBASE-21879 we just read >> the >> >> > > >> HFileBlock >> >> > > >> > to heap which would still lead >> >> > > >> > to high GC pressure. >> >> > > >> > >> >> > > >> > After few months of development and testing, all subtasks have >> >> been >> >> > > >> > resovled now except the HBASE-21946[2] >> >> > > >> > (It depends on HDFS-14483[3] and our HDFS teams are working on >> >> this, >> >> > > we >> >> > > >> > expect the HDFS-14483 to be included >> >> > > >> > in hadoop 2.8.6 and after that the HBASE-21946 will get >> >> resolved). >> >> > we >> >> > > >> think >> >> > > >> > the feature is stable enough now and it's >> >> > > >> > time to merge branch HBASE-21879 back to master now. >> >> > > >> > >> >> > > >> > We have designed 3 test cases to prove the performance >> improvment >> >> > with >> >> > > >> > HBASE-21879: >> >> > > >> > 1. Disabled BlockCache, which means the cacheHitRatio is 0%; >> >> > > >> > 2. CacheHitRatio~65%; >> >> > > >> > 3. CachehHitRatio~100%; >> >> > > >> > >> >> > > >> > In our performance results[4], we can see that: the case#1 >> have >> >> an >> >> > > great >> >> > > >> > performance improvement >> >> > > >> > ( >> >> > > >> > *throughput increased about 17%, heap allocation decreased >> about >> >> > 95%, >> >> > > >> Young >> >> > > >> > generaion size decreased about 81.7%*), that's because after >> >> > > HBASE-21879 >> >> > > >> > all reads will allocate from pooled offheap bytebuffers >> >> > > >> > and almost no heap allocation, while before HBASE-21879 the >> read >> >> > path >> >> > > >> will >> >> > > >> > create so many heap allocations. >> >> > > >> > On the other hand, from the testing results of case#2 and >> case#3 >> >> we >> >> > > can >> >> > > >> > also see that: >> >> > > >> > >> >> > > >> > *As the cacheHitRatioincreasing, the difference between >> >> > > >> before-HBASE-21879 >> >> > > >> > and after-HBASE-21879 will decrease, when cacheHitRatio is >> 100%, >> >> > they >> >> > > >> > almost have no much difference in both throughput and >> latency.* >> >> > > >> > >> >> > > >> > For more details please see the document[4]. Thanks >> >> > > >> > Anoop/Ram/DuoZhang/Stack/GuanghaoZhang very much >> >> > > >> > for your meticulous work (Suggession, discussion, patch >> >> reviewing, >> >> > doc >> >> > > >> > reviewing etc). >> >> > > >> > >> >> > > >> > Please vote >> >> > > >> > >> >> > > >> > [] +1 >> >> > > >> > [] +0/-0 >> >> > > >> > [] -1 Do not merge the branch back because... >> >> > > >> > >> >> > > >> > Thanks. Any suggestions are welcomed. >> >> > > >> > >> >> > > >> > [1] https://issues.apache.org/jira/browse/HBASE-21879 >> >> > > >> > [2] https://issues.apache.org/jira/browse/HBASE-21946 >> >> > > >> > [3] https://issues.apache.org/jira/browse/HDFS-14483 >> >> > > >> > [4] >> >> > > >> > >> >> > > >> > >> >> > > >> >> >> > > >> >> > >> >> >> https://docs.google.com/document/d/1xSy9axGxafoH-Qc17zbD2Bd--rWjjI00xTWQZ8ZwI_E >> >> > > >> > >> >> > > >> >> >> > > > >> >> > > >> >> > >> >> >> > >> >
