Re: Review Request 22980: Enable support for existing cgroups, don't always try to create.

["Timothy St. Clair" <ts...@redhat.com>]

> On June 25, 2014, 10:09 p.m., Ian Downes wrote:
> > src/slave/containerizer/isolators/cgroups/cpushare.cpp, line 236
> > <https://reviews.apache.org/r/22980/diff/1/?file=617510#file617510line236>
> >
> >     Why would the cgroup already exist? The cgroup is based on the containerId which should be unique.
> >     
> >     Is this so the isolator can be re-used for controlling a cgroup added by something like Docker?
> 
> Timothy St. Clair wrote:
>     It's the mounted controller at the root.  
>     
>     export MESOS_isolation='cgroups/cpu,cgroups/mem'
>     export MESOS_cgroups_root='system.slice/mesos-slave.service'
>     export MESOS_hierarchy=/sys/fs/cgroup
>     
>     If you try just starting, it will fail on the exists lines mentioned prior.
> 
> Timothy St. Clair wrote:
>     To elaborate - 
>     
>     $ pwd 
>     /sys/fs/cgroup
>     
>     $ find . | grep mesos
>     ./memory/system.slice/mesos-slave.service
>     ...
>     
>     fails on 'memory'
> 
> Timothy St. Clair wrote:
>     & systemd creates the structure below prior to running the daemon.
> 
> Vinod Kone wrote:
>     I'm still confused. That exists() check is for the particular container's cgroup (e.g. /sys/fs/cgroup/memory/system.slice/mesos-slave.service/84a3b905-5ccc-4b4a-af07-ecf5be88fe53) which should not exist whether we are using systemd or not.

It cascades from the initial create->prepare calls.  Jie was actually the person who helped point this out to me.  Without the modifications slave simply falls over given the predefined input parameters. 


- Timothy


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On June 25, 2014, 7:52 p.m., Timothy St. Clair wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/22980/
> -----------------------------------------------------------
> 
> (Updated June 25, 2014, 7:52 p.m.)
> 
> 
> Review request for mesos, Benjamin Hindman and Vinod Kone.
> 
> 
> Bugs: MESOS-1195
>     https://issues.apache.org/jira/browse/MESOS-1195
> 
> 
> Repository: mesos-git
> 
> 
> Description
> -------
> 
> Currently if a controller is mounted outside of mesos perview it errors out.  This fixes that issue. 
> 
> 
> Diffs
> -----
> 
>   src/slave/containerizer/isolators/cgroups/cpushare.cpp 3265a80 
>   src/slave/containerizer/isolators/cgroups/mem.cpp e8d1e35 
> 
> Diff: https://reviews.apache.org/r/22980/diff/
> 
> 
> Testing
> -------
> 
> make check
> 
> 
> Thanks,
> 
> Timothy St. Clair
> 
>