Re: [vserver] squid in a vserver

From: Art -kwaak- van Breemen <>
Date: Tue 02 Jul 2013 - 11:43:04 BST
Message-ID: <>


On Tue, Jul 02, 2013 at 10:11:05AM +0200, Christian Recktenwald wrote:
> On Mon, Jul 01, 2013 at 08:40:04PM +0200, Christoph Pleger wrote:
> > Hello,
> >
> > We are running squid in a vserver, but this does not work very reliably,
> > because the squid process crashes quite often. It seems that this happens
> > every time when squid is using more than 256 MB of cache memory - the
> > limit is set to a very high value in squid.conf, 24 GB.
> >
> > Do vservers have a memory limit for processes so that a process that needs
> > more is killed?
> first shot: take a look at ulimits (vserver root user
> is not allowed to raise them) and see

Actually memory is not limited usually. Filedescriptors are, and
not by the util-vserver, but by pam. Indeed you can not raise
them and pam lowers them when you log in.
We have mysql servers using 34G of ram, and everything is
We do set limits but those are container group limits.
Christoph: your problem might be that you have turned on
transparent hugetable support. Transparent hugetables and memory
container groups are a continuous cause for OOM's.
Make sure you have that turned off.
Anyway: have something like this in your configuration:

ard@pidsley:/etc/vservers/avserver$ grep . cgroup/* cflags

the cflags are important so the vserver knows what its limits are.

ard@pidsley:/sys/kernel/mm/transparent_hugepage$ cat enabled
[always] madvise never

This should read never, unless you are really really sure you have only one
vserver with one process that uses a lot of memory.

We used squid in a lot of places, but that has been replaced by varnish. Squid
is now only used as an outbound proxy.
If it's necessary I would put a varnish in front of squid, squid has a good
persistent cache, but it's slow compared to varnish. Varnish doesn't have any
persistence, but is amazingly fast. Put a haproxy in front of it for url based
hashing and you have yourself a high performance cache cluster.
Received on Tue Jul 2 11:43:11 2013

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