hadoop-yarn-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Robert Evans <ev...@yahoo-inc.com>
Subject Re: About the cpu-cores and CPU usage
Date Fri, 31 May 2013 15:45:12 GMT
The CPU config is not for physical cores it is for "virtual" cores, an
abstract concept that is not very well documented.  More accurately it is
dividing the CPU on the box into 8 schedule-able chunks. The current Linux
implementation does not limit the utilization within the box.  If there is
a single container that asked for 1 core running on a box it can use all
16 cores with no restrictions.  If there were two 1 core containers
running on the node, then both of them would be limited to about 8
physical cores each.  If you want to reserve CPU specifically for other
processes running on the same box, I don't think that we currently support
that.  You probably want to file a JIRA against YARN describing your use
case.

--Bobby

On 5/31/13 6:05 AM, "Li Shengmei" <lishengmei@ict.ac.cn> wrote:

>Hi, all
>
>         I modify the yarn-site.xml of nodemanager and set
>yarn.nodemanager.resource.cpu-cores as "8". There are "16" cores in
>nodemanager. I use "top" command to monitor the CPU usage while running
>application. I found that all 16 cores are in using. Can anyone explain
>the
>case?
>
> 
>
>Thanks
>
>May
>


Mime
View raw message