varnish is using all file descriptors

Vince cooltechemail at
Mon Jun 20 22:08:35 CEST 2011

We are using CentOS 5.6 64-bit

I'll try set it to a higher number. Do we need to turn any kernel parameters
if we set it to a really high number, say 1M, on CentOS?

However, a higher number doesn't mean we have found the problem. Our varnish
server is serving about 300-400 requests per second. When it runs ok we
checked /proc/PID/fd and it uses less than 100 file descriptors. But when it
goes wrong all 65536 file descriptors have been used. Is this normal?

Thank you!

On Tue, Jun 21, 2011 at 4:02 AM, Per Buer <perbu at>wrote:

> On Mon, Jun 20, 2011 at 9:31 PM, Vince <cooltechemail at> wrote
> > Hi,
> > We had a problem with our varnish server recently that sometimes the
> server
> > will use all file descriptors available to it, which is set to 65536, and
> > start refusing connections. I am wondering how to find out what's the
> real
> > problem behind it.
> Why the insanely low number? Out of the box my laptop has over half a
> million. With 2minutes timeout for reuse on a tcp socket you would run
> of sockets in a jiffie - oh, wait, that's what happening. :-)
> I would set up waaaay up. FD's are really cheap. You could start to
> tune your TCP stack and/or reduce the number of Varnish threads but
> unless you are on a embedded system I wouldn't do it.
> --
> Per Buer, CEO
> Phone: +47 21 98 92 61 / Mobile: +47 958 39 117 / Skype: per.buer
> Varnish makes websites fly!
> Whitepapers | Video | Twitter
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the varnish-misc mailing list