+1 for merge this to master. OpenInx <open...@gmail.com> 于2019年6月21日周五 下午2:56写道：
> 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 > >> >> > > >> > > >> >> > > >> > >> >> > > > > >> >> > > > >> >> > > >> >> > >> > > >> > > >
