[ https://issues.apache.org/jira/browse/MAPREDUCE-4922?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sandy Ryza resolved MAPREDUCE-4922. ----------------------------------- Resolution: Won't Fix This is the expected behavior > Request with multiple data local nodes can cause NPE in AppSchedulingInfo > ------------------------------------------------------------------------- > > Key: MAPREDUCE-4922 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-4922 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: applicationmaster, mr-am, mrv2, scheduler > Affects Versions: 2.0.2-alpha > Reporter: Sandy Ryza > Assignee: Sandy Ryza > > With the way that the schedulers work, each request for a container on a node > must consist of 3 ResourceRequests - one on the node, one on the rack, and > one with *. > AppSchedulingInfo tracks the outstanding requests. When a node is assigned a > node-local container, allocateNodeLocal decrements the outstanding requests > at each level - node, rack, and *. If the rack requests reach 0, it removes > the mapping. > A mapreduce task with multiple data local nodes submits multiple container > requests, one for each node. It also submits one for each unique rack, and > one for *. If there are fewer unique racks than data local nodes, this means > that fewer rack-local ResourceRequests will be submitted than node-local > ResourceRequests, so the rack-local mapping will be deleted before all the > node-local requests are allocated and an NPE will come up the next time a > node-local request from that rack is allocated. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira