Re: [squid-users] Re: should squid crash when ulimit reached?

On Monday 15 August 2005 15:30, Henrik Nordstrom wrote:

> On Fri, 12 Aug 2005, joaoBR wrote:
> > anyway the squid restart under this circunstancies depending on
> > cache size is what is the handicap.
> >
> > what then is very strange for my understandings that when the OS
> > hardcoded limit is not altered then squid crashs soon it reach
> > the limit but when I set it lets say 100MB higher then squid do
> > not crash anymore and stays using memory up at the limit (even
> > when it would use more if available)
>
> It's only a matter of time. See the FAQ on how Squid uses memory.
>

Sorry, what is a matter of time?

> Squid does not care what the limit is, only how it is configured in
> squid.conf which indirectly translates to how much memory Squid
> uses (see FAQ). Your OS limit should be considerably higher than
> this to allow for temporary spikes in memory usage.
>

sure it does not care but crashes when coming to the limit so it got
worse now, it does not care and can not handle it either.

Imagin if common internet aplications, like squid, crash only because
they come temporary to the ulimit. Zillions of sql or apache server
go out of service? Any of them you stress to the limits and when
memory is out, including swap, the server may be rendered or gets
[extremly] slow but the service normally do not crash.

Certainly swap space is exactly for that purpose, holding data when
the RAM is out but squid do not know how to do that exactly and that
is not so good.

It simply crashes and all active connections are dropped, the
cashe_dirs go dirty and often files are damaged and depending on your
cash size your stay long time out of service.

Common sense certainly is to put more RAM in the box and it is beeing
used by applications.

Squid does not. It use max ulimit and crash. That is somewhat hard to
understand. This is only my opinion but new users or not
OS-tweak-skilled people can not understand this issue and may be they
do never get really something out of squid. Ok, you may say with
default cache_mem 8Mb this never happens but with this setting squid
does not give me any benefit either.

This behaviour some years ago when most people still used dialup and
the ISPs had low-BW-Uplinks then it was not an issue.

Todays high bandwidth requirements for ADSL and wireless ISPs are
demanding more stable services and really high network peaks are very
usual and common and often unpredictable. I think squid needs to be
reviewed on this issue because the ulimit crash is a serious problem
I think.

Hans
Received on Tue Aug 16 2005 - 03:59:57 MDT