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Wangda Tan commented on YARN-3243: ---------------------------------- Javadoc warning are mis-reported by Jenkins, findbugs warnings are tracked by YARN-3204, test failures can pass locally. > CapacityScheduler should pass headroom from parent to children to make sure > ParentQueue obey its capacity limits. > ----------------------------------------------------------------------------------------------------------------- > > Key: YARN-3243 > URL: https://issues.apache.org/jira/browse/YARN-3243 > Project: Hadoop YARN > Issue Type: Bug > Components: capacityscheduler, resourcemanager > Reporter: Wangda Tan > Assignee: Wangda Tan > Attachments: YARN-3243.1.patch, YARN-3243.2.patch, YARN-3243.3.patch, > YARN-3243.4.patch > > > Now CapacityScheduler has some issues to make sure ParentQueue always obeys > its capacity limits, for example: > 1) When allocating container of a parent queue, it will only check > parentQueue.usage < parentQueue.max. If leaf queue allocated a container.size > > (parentQueue.max - parentQueue.usage), parent queue can excess its max > resource limit, as following example: > {code} > A (usage=54, max=55) > / \ > A1 A2 (usage=1, max=55) > (usage=53, max=53) > {code} > Queue-A2 is able to allocate container since its usage < max, but if we do > that, A's usage can excess A.max. > 2) When doing continous reservation check, parent queue will only tell > children "you need unreserve *some* resource, so that I will less than my > maximum resource", but it will not tell how many resource need to be > unreserved. This may lead to parent queue excesses configured maximum > capacity as well. > With YARN-3099/YARN-3124, now we have {{ResourceUsage}} class in each class, > *here is my proposal*: > - ParentQueue will set its children's ResourceUsage.headroom, which means, > *maximum resource its children can allocate*. > - ParentQueue will set its children's headroom to be (saying parent's name is > "qA"): min(qA.headroom, qA.max - qA.used). This will make sure qA's > ancestors' capacity will be enforced as well (qA.headroom is set by qA's > parent). > - {{needToUnReserve}} is not necessary, instead, children can get how much > resource need to be unreserved to keep its parent's resource limit. > - More over, with this, YARN-3026 will make a clear boundary between > LeafQueue and FiCaSchedulerApp, headroom will consider user-limit, etc. -- This message was sent by Atlassian JIRA (v6.3.4#6332)