Thanks everyone for the thoughtful comments. We completed the last patch required (YARN-3659) for testing the YARN-2915 branch e2e yesterday. I'll go ahead and start a vote thread as soon as the validations are done as there were no blockers raised.
Cheers, Subru & Carlo On Fri, Jun 23, 2017 at 5:11 PM, Wangda Tan <[email protected]> wrote: > Thanks all for working on the feature, I'm in favor of moving forward as > well. > > Best, > Wangda > > On Fri, Jun 23, 2017 at 2:44 PM, Sangjin Lee <[email protected]> wrote: > >> Thanks for the clarification Subru. I am in favor of moving forward. >> >> >> Sangjin >> >> On Thu, Jun 22, 2017 at 6:21 PM, Karthik Shashank Kambatla < >> [email protected]> wrote: >> >> > Given RTC and the amount of production testing this feature has >> received, I >> > am totally in favor of this merge. >> > >> > >> > >> > On Tue, Jun 20, 2017 at 4:28 PM, Subru Krishnan <[email protected]> >> wrote: >> > >> > > Hi all, >> > > >> > > We would like to open a discussion on merging the YARN Federation >> > > (YARN-2915) [1] feature to trunk. We have been developing the feature >> > in a >> > > feature branch (YARN-2915 [2]) for a while, and we are reasonably >> > confident >> > > that the state of the feature meets the criteria to be merged onto >> trunk. >> > > >> > > *Key Ideas*: >> > > >> > > YARN’s centralized design allows strict enforcement of scheduling >> > > invariants and effective resource sharing, but becomes a scalability >> > > bottleneck (in number of jobs and nodes) well before reaching the >> scale >> > of >> > > our clusters (e.g., 20k-50k nodes). >> > > >> > > >> > > To address these limitations, we developed a scale-out, >> federation-based >> > > solution (YARN-2915). Our architecture scales near-linearly to >> datacenter >> > > sized clusters, by partitioning nodes across multiple sub-clusters >> (each >> > > running a YARN cluster of few thousands nodes). Applications can span >> > > multiple sub-clusters *transparently (i.e. no code change or >> > recompilation >> > > of existing apps)*, thanks to a layer of indirection that negotiates >> with >> > > multiple sub-clusters' Resource Managers on behalf of the application. >> > > >> > > >> > > This design is structurally scalable, as it bounds the number of nodes >> > each >> > > RM is responsible for. Appropriate policies ensure that the majority >> of >> > > applications reside within a single sub-cluster, thus further >> controlling >> > > the load on each RM. This provides near linear scale-out by simply >> adding >> > > more sub-clusters. The same mechanism enables pooling of resources >> from >> > > clusters owned and operated by different teams. >> > > >> > > Status: >> > > >> > > - The version we would like to merge to trunk is termed "MVP" >> (minimal >> > > viable product). The feature will have a complete end-to-end >> > application >> > > execution flow with the ability to span a single application across >> > > multiple YARN (sub) clusters. >> > > - There were 50+ sub-tasks that were that were completed as part of >> > this >> > > effort. Every patch has been reviewed and +1ed by a committer. >> Thanks >> > to >> > > Jian, Wangda, Karthik, Vinod, Varun & Arun for the thorough >> reviews! >> > > - Federation is designed to be built around YARN and consequently >> has >> > > minimal code changes to core YARN. The relevant JIRAs that modify >> > > existing >> > > YARN code base are YARN-3671 [7] & YARN-3673 [8]. We also paid >> close >> > > attention to ensure that if federation is disabled there is zero >> > impact >> > > to >> > > existing functionality (disabled by default). >> > > - We found a few bugs as we went along which we fixed directly >> > upstream >> > > in trunk and/or branch-2. >> > > - We have continuously rebasing the feature branch [2] so the merge >> > > should be a straightforward cherry-pick. >> > > - The current version has been rather thoroughly tested and is >> > currently >> > > deployed in a *10,000+ node federated YARN cluster that's running >> > > upwards of 50k jobs daily with a reliability of 99.9%*. >> > > - We have few ideas for follow-up extensions/improvements which are >> > > tracked in the umbrella JIRA YARN-5597[3]. >> > > >> > > >> > > Documentation: >> > > >> > > - Quick start guide (maven site) - YARN-6484[4]. >> > > - Overall design doc[5] and the slide-deck [6] we used for our >> talk at >> > > Hadoop Summit 2016 is available in the umbrella jira - YARN-2915. >> > > >> > > >> > > Credits: >> > > >> > > This is a group effort that could have not been possible without the >> > ideas >> > > and hard work of many other folks and we would like to specifically >> call >> > > out Giovanni, Botong & Ellen for their invaluable contributions. Also >> big >> > > thanks to the many folks in community (Sriram, Kishore, Sarvesh, >> Jian, >> > > Wangda, Karthik, Vinod, Varun, Inigo, Vrushali, Sangjin, Joep, Rohith >> and >> > > many more) that helped us shape our ideas and code with very >> insightful >> > > feedback and comments. >> > > >> > > We plan to start the merge vote in the next week or so. The branch is >> > close >> > > to complete (~5 patches before one can kick the tires on a running >> > > deployment). Please look through the branch; feedback is welcome. >> Thanks! >> > > >> > > Cheers, >> > > Subru & Carlo >> > > >> > > [1] YARN-2915: https://issues.apache.org/jira/browse/YARN-2915 >> > > [2] https://github.com/apache/hadoop/tree/YARN-2915 >> > > [3] YARN-5597: https://issues.apache.org/jira/browse/YARN-5597 >> > > [4] YARN-6484: https://issues.apache.org/jira/browse/YARN-6484 >> > > [5] https://issues.apache.org/jira/secure/attachment/12733292/ >> > > Yarn_federation_design_v1.pdf >> > > [6] https://issues.apache.org/jira/secure/attachment/1281922 >> > > 9/YARN-Federation-Hadoop-Summit_final.pptx >> > > [7] YARN-3671: https://issues.apache.org/jira/browse/YARN-3671 >> > > [8] YARN-3673: https://issues.apache.org/jira/browse/YARN-3673 >> > > >> > >> > >
