[ https://issues.apache.org/jira/browse/YARN-1662?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sunil G resolved YARN-1662. --------------------------- Resolution: Invalid > Capacity Scheduler reservation issue cause Job Hang > --------------------------------------------------- > > Key: YARN-1662 > URL: https://issues.apache.org/jira/browse/YARN-1662 > Project: Hadoop YARN > Issue Type: Bug > Components: resourcemanager, scheduler > Affects Versions: 2.2.0 > Environment: Suse 11 SP1 + Linux > Reporter: Sunil G > > There are 2 node managers in my cluster. > NM1 with 8GB > NM2 with 8GB > I am submitting a Job with below details: > AM with 2GB > Map needs 5GB > Reducer needs 3GB > slowstart is enabled with 0.5 > 10maps and 50reducers are assigned. > 5maps are completed. Now few reducers got scheduled. > Now NM1 has 2GB AM and 3Gb Reducer_1 [Used 5GB] > NM2 has 3Gb Reducer_2 [Used 3GB] > A Map has now reserved(5GB) in NM1 which has only 3Gb free. > It hangs forever. > Potential issue is, reservation is now blocked in NM1 for a Map which needs > 5GB. > But the Reducer_1 hangs by waiting for few map ouputs. > Reducer side preemption also not happened as few headroom is still available. -- This message was sent by Atlassian JIRA (v6.3.4#6332)