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https://issues.apache.org/jira/browse/MESOS-458?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13695993#comment-13695993
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Ian Downes commented on MESOS-458:
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Regarding the last example, I don't think that 1024 == 1 cpu, rather (say) the
system would get 1024 / (1024 + 1024 + sum(mesos*)), i.e. it's a weighted
fraction. Am I interpreting this incorrectly?
> Current cgroups layout does not ensure the slave gets a fair share of the CPU
> resources.
> ----------------------------------------------------------------------------------------
>
> Key: MESOS-458
> URL: https://issues.apache.org/jira/browse/MESOS-458
> Project: Mesos
> Issue Type: Improvement
> Reporter: Benjamin Mahler
>
> We currently have the following layout when there is no system cgroup present
> on a machine:
> /cgroup: (system processes, including the mesos-slave) 1024 shares
> /cgroup/mesos: (no processes) 1024 shares
> /cgroup/mesos/executor1: X shares
> ...
> /cgroup/mesos/executorN: X shares
> This does not ensure the slave gets a fair share of the cpu, especially when
> there is load inside the root cgroup. This is because the slave is contending
> with other processes inside the root cgroup. If the administrators set up a
> system cgroup, the layout looks as follows:
> /cgroup: (no processes)
> /cgroup/system: (system processes, including the mesos-slave) 1024 shares
> /cgroup/mesos: (no processes) 1024 shares
> /cgroup/mesos/executor1: X shares
> ...
> /cgroup/mesos/executorN: X shares
> This still does not ensure the slave gets a fair share for the same reasons.
> However, if we create a cgroup to hold only the slave:
> /cgroup: (no processes)
> /cgroup/system: (system processes) 1024 shares
> /cgroup/mesos-slave: (mesos-slave process) 1024 shares
> /cgroup/mesos: (no processes) 1024 shares
> /cgroup/mesos/executor1: X shares
> ...
> /cgroup/mesos/executorN: X shares
> With the above configuration, the slave will get 1 cpu, system processes will
> get 1 cpu, and the executors will get the rest.
> See the following link for sharing behavior in the root cgroup:
> https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Resource_Management_Guide/process_behavior.html
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