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Wangda Tan commented on YARN-4333: ---------------------------------- [~Tao Jie], I've added you to contributor list and assigned the JIRA to you. > Fair scheduler should support preemption within queue > ----------------------------------------------------- > > Key: YARN-4333 > URL: https://issues.apache.org/jira/browse/YARN-4333 > Project: Hadoop YARN > Issue Type: Improvement > Components: fairscheduler > Affects Versions: 2.6.0 > Reporter: Tao Jie > Assignee: Tao Jie > Attachments: YARN-4333.001.patch > > > Now each app in fair scheduler is allocated its fairshare, however fairshare > resource is not ensured even if fairSharePreemption is enabled. > Consider: > 1, When the cluster is idle, we submit app1 to queueA,which takes maxResource > of queueA. > 2, Then the cluster becomes busy, but app1 does not release any resource, > queueA resource usage is over its fairshare > 3, Then we submit app2(maybe with higher priority) to queueA. Now app2 has > its own fairshare, but could not obtain any resource, since queueA is still > over its fairshare and resource will not assign to queueA anymore. Also, > preemption is not triggered in this case. > So we should allow preemption within queue, when app is starved for fairshare. -- This message was sent by Atlassian JIRA (v6.3.4#6332)