[
https://issues.apache.org/jira/browse/FLINK-19710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17244935#comment-17244935
]
Brad Davis commented on FLINK-19710:
------------------------------------
The reason for my interest is that I'm working on a Flink application that will
run on an AWS EMR cluster and we wanted to use the new ARM64 based hosts.
Unfortunately the 5.x JNI library doesn't include an ARM64 binary, but the 6.x
series apparently does.
> Fix performance regression to rebase FRocksDB with higher version RocksDB
> -------------------------------------------------------------------------
>
> Key: FLINK-19710
> URL: https://issues.apache.org/jira/browse/FLINK-19710
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / State Backends
> Reporter: Yun Tang
> Assignee: Yun Tang
> Priority: Major
> Fix For: 1.13.0
>
>
> We planed to bump base rocksDB version from 5.17.2 to 6.11.x. However, we
> observed performance regression compared with 5.17.2 and 5.18.3 via our own
> flink-benchmarks, and reported to RocksDB community in
> [rocksdb#5774|https://github.com/facebook/rocksdb/issues/5774]. Since
> rocksDB-5.18.3 is a bit old for RocksDB community, and rocksDB built-in
> db_bench tool cannot easily reproduce this regression, we did not get any
> efficient help from RocksDB community.
> Since code freeze of Flink-release-1.12 is close, we have to figure it out by
> ourself. We try to use rocksDB built-in db_bench tool first to binary
> searching the 160 different commits between rocksDB 5.17.2 and 5.18.3.
> However, the performance regression is not so clear. And after using our own
> flink-benchmarks. We finally detect the commit which introduced the
> nearly-10% performance regression: [replaced __thread with thread_local
> keyword
> |https://github.com/facebook/rocksdb/commit/d6ec288703c8fc53b54be9e3e3f3ffd6a7487c63]
> .
> From existing knowledge, the performance regression of {{thread-local}} is
> known from [gcc-4.8 changes|https://gcc.gnu.org/gcc-4.8/changes.html#cxx] and
> become more serious in [dynamic modules usage
> |http://david-grs.github.io/tls_performance_overhead_cost_linux/] [[tls
> benchmark|https://testbit.eu/2015/thread-local-storage-benchmark]]]. That
> could explain why rocksDB built-in db_bench tool cannot reproduce this
> regression as it is complied in static mode by recommendation.
>
> We plan to fix this in our FRocksDB branch first to revert related changes.
> And from my current local experimental result, that revert proved to be
> effective to avoid that performance regression.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
