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 >
