Varnish 2.1 + kswapd0 freak out

[Michael Fischer]

+1

Add some swap.  And be sure to watch your swap paging activity.

--Michael

On Fri, May 21, 2010 at 3:30 PM, Ken Brownfield <kb+varnish at slide.com> wrote:
> This happens when there is significant memory pressure (heavy network or block I/O exacerbates it) when you have swap disabled.  This is a long-standing kernel behavior issue, from my experience.  I've seen it with MySQL and other servers, in addition to Varnish.
>
> That being said, perhaps Varnish is initiating a huge object expiry pass that's triggering this problem.  If you increase the cli_timeout, it may help prevent the child from being reaped, to probably dubious benefit.
>
> Increasing /proc/sys/vm/min_free_kbytes (by 2-3x) may also help, but it's a dangerous beast.  I use 131072 for all of my Varnish instances, for this reason (16-64GB boxes).
>
> You may also find that adding a few hundred meg of swap is the lesser of two evils.
>
> Hope it helps,
> --
> Ken
>
> On May 20, 2010, at 3:45 PM, Augusto Becciu wrote:
>
>> We don't have swap enabled on these servers.
>
>
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