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 > > > >> > > > > >> > > > > > > > > > >
