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Hi, Francisco,<br>
<br>
<div class="moz-cite-prefix">On 04.09.15 02:05, Francisco Tolmasky
wrote:<br>
</div>
<blockquote
cite="mid:CADRmq79Q_y2A1D1q12Asm4v9291wqA+GbPRAJPvmgeV4kn8jXA@mail.gmail.com"
type="cite">
<div dir="ltr">So I have been tracking a bug in tonic (related to
this logging issue, and general “breaking” of pipes/streams),
and I have narrowed part of the problem to the fact that we
restore multiple containers simultaneously from the same source
run. We do this to have them “warm” and ready in case the user
wants to go back to a previous checkpoint. So something along
these lines happens:
<div><br>
</div>
<div>Program is running -> Checkpoint -> immediate restore
IN PARALLEL to original program/restore from previous
checkpoint IN PARALLEL as well.</div>
<div><br>
</div>
<div>So, you can end up with up to 3 copies of the same program
running. Eventually that original one will die and we will
choose one of the two “waiting” copies to pick up from.</div>
<div><br>
</div>
<div>So, my first question is whether you would expect things to
start breaking in this scenario (they seem to work a lot of
times, again, we see occasional failures over time in the form
of stream breakages possibly, or just getting “stuck” (I
believe it gets stuck waiting on a pipe though)). </div>
<div><br>
</div>
</div>
</blockquote>
<br>
Could you provide some logs, please?<br>
<br>
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cite="mid:CADRmq79Q_y2A1D1q12Asm4v9291wqA+GbPRAJPvmgeV4kn8jXA@mail.gmail.com"
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<div dir="ltr">
<div>My second question is, if this is in fact not expected to
work well, would it be possible to “Restore” a container but
not “start” it. That is, load up the memory get everything
ready but have it waiting for a signal to actually kick off
and get going. That way we can get most the benefit of
pre-warming these restores, without having them all actually
running at once.</div>
<div><br>
</div>
</div>
</blockquote>
<br>
That's a great question. I've been thinking about implementing
--leave-stopped for restore, but never actually came to that. I've
tried just adding || opts.final_state == TASK_STOPPED to
<a class="moz-txt-link-freetext" href="https://github.com/xemul/criu/blob/master/cr-restore.c#L1715">https://github.com/xemul/criu/blob/master/cr-restore.c#L1715</a> and it
seems to work just fine with a test loop, though I'm not sure that
it will always work in more complicated scenarios.<br>
<br>
Also added this task to TODO list[1].<br>
<br>
[1] <a class="moz-txt-link-freetext" href="http://criu.org/Todo">http://criu.org/Todo</a><br>
<br>
<blockquote
cite="mid:CADRmq79Q_y2A1D1q12Asm4v9291wqA+GbPRAJPvmgeV4kn8jXA@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>Thanks,</div>
<div><br>
</div>
<div>Francisco<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature">Francisco Tolmasky<br>
<a moz-do-not-send="true" href="http://www.tolmasky.com"
target="_blank">www.tolmasky.com</a><br>
<a moz-do-not-send="true" href="mailto:tolmasky@gmail.com"
target="_blank">tolmasky@gmail.com</a></div>
</div>
</div>
<br>
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