Hi all, >From discussion at [1], I'd like to start a vote to merge feature branch YARN-5734 to trunk, branch-3.0, and branch-2. Vote will be 7 days, ending Monday Oct 9 at 11:00AM PDT.
This branch adds a framework to the scheduler to allow scheduler configuration mutation on the fly, including a REST and CLI interface, and an interface for the scheduler configuration backing store. Currently the capacity scheduler implements this framework. Umbrella is here (YARN-5734 <https://issues.apache.org/jira/browse/YARN-5734>), jenkins build is here ( YARN-7241 <https://issues.apache.org/jira/browse/YARN-7241>). All required tasks for this feature are committed. Since this feature changes RM only, we have tested this on a local RM setup with a suite of configuration changes with no issue so far. Key points: - The feature is turned off by default, and must be explicitly configured to turn on. When turned off, the behavior reverts back to the original file based mechanism for changing scheduler configuration (i.e. yarn rmadmin -refreshQueues). - The framework was designed in a way to be extendable to other schedulers (most notably FairScheduler). - A pluggable ACL policy (YARN-5949 <https://issues.apache.org/jira/browse/YARN-5949>) allows admins fine-grained control for who can change what configurations. - The configuration storage backend is also pluggable. Currently an in-memory, leveldb, and zookeeper implementation are supported. There were 15 subtasks completed for this feature. Huge thanks to everyone who helped with reviews, commits, guidance, and technical discussion/design, including Carlo Curino, Xuan Gong, Subru Krishnan, Min Shen, Konstantin Shvachko, Carl Steinbach, Wangda Tan, Vinod Kumar Vavilapalli, Suja Viswesan, Zhe Zhang, Ye Zhou. [1] http://mail-archives.apache.org/mod_mbox/hadoop-yarn-dev/201709.mbox/%3CCAHzWLgfEAgczjcEOUCg-03ma3ROtO=pkec9dpggyx9rzf3n...@mail.gmail.com%3E Jonathan Hung
