Hi Gary, + 1 to remove it for now. Actually some users are not aware of that it’s still experimental, and ask quite a lot about the problem it causes.
Best, Paul Lam > 在 2019年4月24日，14:49，Stephan Ewen <se...@apache.org> 写道： > > Sounds reasonable to me. If it is a broken feature, then there is not much > value in it. > > On Tue, Apr 23, 2019 at 7:50 PM Gary Yao <g...@ververica.com> wrote: > >> Hi all, >> >> As the subject states, I am proposing to temporarily remove support for >> changing the parallelism of a job via the following syntax [1]: >> >> ./bin/flink modify [job-id] -p [new-parallelism] >> >> This is an experimental feature that we introduced with the first rollout >> of >> FLIP-6 (Flink 1.5). However, this feature comes with a few caveats: >> >> * Rescaling does not work with HA enabled [2] >> * New parallelism is not persisted, i.e., after a JobManager restart, >> the job >> will be recovered with the initial parallelism >> >> Due to the above-mentioned issues, I believe that currently nobody uses >> "modify -p" to rescale their jobs in production. Moreover, the rescaling >> feature stands in the way of our current efforts to rework Flink's >> scheduling >> [3]. I therefore propose to remove the rescaling code for the time being. >> Note >> that it will still be possible to change the parallelism by taking a >> savepoint >> and restoring the job with a different parallelism [4]. >> >> Any comments and suggestions will be highly appreciated. >> >> Best, >> Gary >> >> [1] >> https://ci.apache.org/projects/flink/flink-docs-release-1.8/ops/cli.html >> [2] https://issues.apache.org/jira/browse/FLINK-8902 >> [3] https://issues.apache.org/jira/browse/FLINK-10429 >> [4] >> >> https://ci.apache.org/projects/flink/flink-docs-release-1.8/ops/state/savepoints.html#what-happens-when-i-change-the-parallelism-of-my-program-when-restoring >>
