Re: [squid-users] CPU saturation?

On Wed, 2005-11-16 at 12:41 +0000, James Vanns wrote:
> <snip>
> > > With approximately 3000 open file descriptors (configured at compile
> > > time and set at runtime with ulimit -HSn 16384) and an equivalent no. of
> > > client/server TCP connections we see a constant CPU usage of ~95-100%.
> > > Is this normal!? The hardware is as follows:
> >
> > I don't think so. Try strace and ltrace on running squid.
>
> Yeah I have actually run squid through strace and the only alarming
> thing is the huge amount of bind() calls on 0.0.0.0 and port htons (0).
> And by huge amount I mean practically every lookup (I guess somehow this
> is related to the internal DNS lookups).

Sorry I should have said 'squid's internal resolver' to avoid
confusion ;)

> Surely you don't need to call
> bind() for every query!? Or am I missing something here? Admittedly I
> didn't spend much time analysing the strace output.
>
> > > Dual Intel(R) Xeon(TM) CPU 3.20GHz (Linux of course manages the CPU
> > > affinity as we know squid isn't multi-threaded)
> > > 6G of memory
> >
> > IIUC one squid will load only one CPU, how do you get "95-100%" load
> > on both?
>
> You misunderstand (I think). That percentage I gave was per CPU e.g.
> 95-100% usage on CPU0 not across all (0-3) processors.
>
> Jim
>
> > --
> > vda
> --
> James Vanns BSc (Hons) MCP
> Canterbury Christ Church University
> Senior Systems Programmer (Linux / C & C++)
> Encryption Key: http://keys.se.linux.org/pks/lookup?op=get&search=0x3B09EE224A653EA9
> Signature Verification Key: http://keys.se.linux.org/pks/lookup?op=get&search=0x47FF170724959054
>

-- 
James Vanns BSc (Hons) MCP
Canterbury Christ Church University
Senior Systems Programmer (Linux / C & C++)
Encryption Key: http://keys.se.linux.org/pks/lookup?op=get&search=0x3B09EE224A653EA9
Signature Verification Key: http://keys.se.linux.org/pks/lookup?op=get&search=0x47FF170724959054