[
https://issues.apache.org/jira/browse/YARN-1662?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Sunil G updated YARN-1662:
--------------------------
Attachment: (was: Yarn-1.2.patch)
> 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
> 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
(v6.2#6252)
