Strange load issue with 2.4.17

[Simon Matter]

> Hi,
>
> for the last week we have seen strange load issues on our Cyrus server.
> All
> of a sudden the load increases to several thousands, user CPU goes down to
> basically zero, system CPU spikes. In the past we've had trouble with poor
> I/O performance, but that went along with an increase in Wait I/O. We
> don't
> see that now. vmstat shows a massive increase in context switches. When
> the
> system reaches this state, all we can do is restart Cyrus or reboot the
> machine if that doesn't work anymore.
>
> I'm attaching a Ganglia screenshot that shows the problem clearly. When
> the
> problem exists, there's not much we can do to analyze it. A colleague
> suggested that what we see could be related to this bug:
>
> https://bugzilla.cyrusimap.org/show_bug.cgi?id=3744
>
> It was reported for 2.4.16, and it sounds as if it has been fixed, but is
> that fix really part of 2.4.17? Any other ideas?

Is this a physical host or running virtualized?

Simon