Hi Whitney,

As Vinod said, 0.18.0 will ensure the kernel is set handle OOM
conditions. The patches you linked are refactors that should not have
changed the behavior since 0.18.0. Could you please double check that
/sys/fs/cgroup/memory/memory.oom.control has "oom_kill_disable 0"?

Can you attempt to reproduce this outside of Mesos by running a
process inside a manually created memory cgroup. Something like the dd
command in the thread you linked should trigger the OOM handler to run
and probably kill processes. Or, perhaps run your java process with a
much lower memory limit.

>From the trace you provided I see mention of ext4 write so it looks
like the OOM handler is indeed trying to flush dirty pages to disk.
Are you running this on EBS? If so, there could be timing issues here
that the kernel isn't handling well; can you test using just the
ephemeral disk(s)?

Please do let us know how this goes!

Ian

On Tue, Jul 1, 2014 at 10:17 AM, Vinod Kone <[email protected]> wrote:
> Hey Whitney,
>
> I'll let Ian Downes comment on the specific patches you linked, but at a
> high level the bug in MESOS-662 was due to Mesos trying to handle OOM
> situations in user space instead of letting kernel handle it. We have since
> then changed the behavior to let Kernel handle the OOM. You can confirm this
> by checking "oom.control" file in the cgroup of your container (it should
> say 'oom_kill_disable 0').
>
>
> On Tue, Jul 1, 2014 at 9:12 AM, Whitney Sorenson <[email protected]>
> wrote:
>>
>> We've been running a few clusters on Amazon EC2 with mesos 0.18.0 on the
>> new generation C3 machines (generally c3.8xl) and have been experiencing
>> frequent system reboots.
>>
>> Due to this issue
>> (http://mail-archives.apache.org/mod_mbox/mesos-user/201406.mbox/%3CCAJRB3TEj%2Bx4VRYicJM7aj7avcjr6QeXR8BmSUehrc6_tV62DLw%40mail.gmail.com%3E)
>> we have been experimenting with some 3.10.25-1.el6.elrepo.x86_64 kernel
>> machines (the rest of the cluster is 2.6.32-431.el6.x86_64). Both sets of
>> machines seem equally likely to experience reboots, although the 3.10
>> machines do not come back unaided.
>>
>> It seems that the kernel runs into problems in the OOM handler, and we see
>> traces such as:
>>
>> [378328.089052] BUG: soft lockup - CPU#17 stuck for 22s! [java7:23300]
>> (https://gist.github.com/wsorenson/d2a12f1892b43aa28936)
>>
>> Is this possibly related to
>> https://issues.apache.org/jira/browse/MESOS-662 ?
>>
>> Any guidance on how to debug further or if this is a known issue with
>> certain mesos versions? Some sleuthing indicates that a patch for the above
>> may have been added, removed, and added again later.
>>
>> Amazon has suggested using 3.10.45-1.el6.elrepo.x86_64 since they report
>> some cgroup deadlock fixes. We are testing this out asap.
>>
>> Thanks,
>>
>> -Whitney
>
>

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