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Posted to yarn-issues@hadoop.apache.org by "Zhankun Tang (JIRA)" <ji...@apache.org> on 2019/02/13 04:17:00 UTC

[jira] [Comment Edited] (YARN-9294) Potential race condition in setting GPU cgroups & execute command in the selected cgroup

    [ https://issues.apache.org/jira/browse/YARN-9294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16766760#comment-16766760 ] 

Zhankun Tang edited comment on YARN-9294 at 2/13/19 4:16 AM:
-------------------------------------------------------------

[~oliverhuhuhu@gmail.com] , Yeah. Agree with the plan. And to find the stable reproducing steps seems a good start to me. We can write a script to create sub device cgroups and use "container-executor" to set parameter and then attach the running processes to verify if anyone sees the denied devices.


was (Author: tangzhankun):
[~oliverhuhuhu@gmail.com] , Yeah. Agree with the plan. And to find the stable reproducing steps seems a good start to me. We can write a script to create sub device cgroups and use "container-executor" to set parameter and then attach the processes repeatedly to verify if someone sees denied devices.

> Potential race condition in setting GPU cgroups & execute command in the selected cgroup
> ----------------------------------------------------------------------------------------
>
>                 Key: YARN-9294
>                 URL: https://issues.apache.org/jira/browse/YARN-9294
>             Project: Hadoop YARN
>          Issue Type: Bug
>          Components: yarn
>    Affects Versions: 2.10.0
>            Reporter: Keqiu Hu
>            Assignee: Keqiu Hu
>            Priority: Critical
>
> Environment is latest branch-2 head
> OS: RHEL 7.4
> *Observation*
> Out of ~10 container allocations with GPU requirement, at least 1 of the allocated containers would lose GPU isolation. Even if I asked for 1 GPU, I could still have visibility to all GPUs on the same machine when running nvidia-smi.
> The funny thing is even though I have visibility to all GPUs at the moment of executing container-executor (say ordinal 0,1,2,3), but cgroups jailed the process's access to only that single GPU after sometime. 
> The underlying process trying to access GPU would take the initial information as source of truth and try to access physical 0 GPU which is not really available to the process. This results in a [CUDA_ERROR_INVALID_DEVICE: invalid device ordinal] error.
> Validated the container-executor commands are correct:
> {code:java}
> PrivilegedOperationExecutor command: [/export/apps/hadoop/nodemanager/latest/bin/container-executor, --module-gpu, --container_id, container_e22_1549663278916_0249_01_000001, --excluded_gpus, 0,1,2,3]
> PrivilegedOperationExecutor command: 
> [/export/apps/hadoop/nodemanager/latest/bin/container-executor, khu, khu, 0, application_1549663278916_0249, /grid/a/tmp/yarn/nmPrivate/container_e22_1549663278916_0249_01_000001.tokens, /grid/a/tmp/yarn, /grid/a/tmp/userlogs, /export/apps/jdk/JDK-1_8_0_172/jre/bin/java, -classpath, ..., -Xmx256m, org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer, khu, application_1549663278916_0249, container_e22_1549663278916_0249_01_000001, ltx1-hcl7552.grid.linkedin.com, 8040, /grid/a/tmp/yarn]
> {code}
> So most likely a race condition between these two operations? 
> cc [~jhung]
> Another potential theory is the cgroups creation for the container actually failed but the error was swallowed silently.



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