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" <[email protected]> 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 >
