(Apologies if it is delivered twice.) YARN Devs,
We propose to merge YARN-1051 development branch into trunk. Key Idea: This work adds support for Reservations to YARN RM. The key idea is to allow users to request dedicated access to resources (a reservation), ahead of time. For example I can ask for "10 containers for 1 hour sometime between 4pm and 9pm today". The RM keeps track of the accepted reservation by means of a Plan (think it as an agenda on how the cluster resources will be used), and performs admission control to guarantee that if a reservation is accepted enough resources are set aside to satisfy it. We enforce the reservation promises by dynamically creating/resizing/removing queues at the right time. This allows us to leverage the existing schedulers for the actual container assignment and tracking. The key benefit is to expose to the scheduler flexibility of allocation, while guaranteeing users predictable resource allocation. Status * The work has been "broken down" into 14 subtasks (+3 patches already committed to trunk for move/kill of apps). All the issues have been resolved. * Jenkins +1 the patch (with the exception of one test failure which we did not introduce, which is tracked here: https://issues.apache.org/jira/browse/MAPREDUCE-6094) * Simple integration with MapReduce: https://issues.apache.org/jira/browse/MAPREDUCE-6103 * The broken-down patches have been reviewed and +1ed by Vinod Kumar Vavilapali, Jian He, Wangda Tan, Karthik Kambatla, and Chris Douglas. Thanks to all of you for the thorough reviews! * The current version has been rather thoroughly tested by running it on our 250 machines research cluster for months (first prototype was operational about a year ago) by: o Running hundreds of thousands of job generate by a modified version of gridmix that exercise the reservations mechanism side-by-side normal queues. o To support our integration with the resource estimation framework Perforator (http://research.microsoft.com/pubs/178971/perforator.pdf). Kaushik and Dharmesh have been pounding the reservation system for their research for 3-4 months now, and helped us spot few bugs and iron them out. o Code has been inspected/extended by 4-5 other researchers which are exploring integration with other systems and extensions of our algorithms for "reservation placement". * We have few ideas for follow-up extensions/improvements are tracked by the umbrella JIRA https://issues.apache.org/jira/browse/YARN-2572 Documents and Deliverables * This work was accepted for publication to SoCC 2014 (pre-camera ready version of the paper here): https://issues.apache.org/jira/secure/attachment/12671498/socc14-paper15.pdf * Shorter design doc: https://issues.apache.org/jira/secure/attachment/12628330/YARN-1051-design.pdf * Overall patch: https://issues.apache.org/jira/secure/attachment/12671361/YARN-1051.1.patch * Per Karthik request we are preparing a small how-to document and example code/configuration tracked by https://issues.apache.org/jira/browse/YARN-2609 Credits Myself and Subru did lots of the coding (hence the flow of patches from us), but this is a group effort that could have not been possible without the ideas and hard work of many other folks in our research group (Microsoft-CISL). Major kudos to: Chris Douglas, Sriram Rao, Raghu Ramakrishnan, and our intern Djellel Difallah. Also big thanks to the many folks in community (Arun, Vinod, Alejandro, Bikas, Karthik, Sandy, Hitesh, Jakob, Mohammad, Mayank, Jason, Bobby, and many more) that helped us shape our ideas and code with very insightful feedback and comments. We expect the vote to run for the usual 7 days and will expire at 12pm PDT on Oct 3. Please feel free to reach out to us if you have any questions/doubts. Cheers, Carlo & Subru
