Re: [squid-users] How to determine the number of file descriptors for Squid?

Mark,

1024 file descriptors were fine until few days ago when the warning
messages started appearing in the cache.log file. I had to reboot the
machine to reset the file descriptors.

We are still investigating the issue but I believe the cause of it was in
changing the caching policy for Squid. Not all of the content served by
Squid had proper HTTP headers to direct Squid how to cache it. When we
discovered that some of the content was stale and not refreshed we decided
to cache only part of the application content until we fine tune the
caching strategy in our application. This created different traffic
pattern. Squid forwarded most of the request to the application and cached
only a fraction of the content.

I believe this change in the configuration increased the number of
simultaneously opened file handlers in Squid.

Thanks for the suggestions.

Dimitar

Mark Elsen <mark.elsen@gmail.com>
09/18/2005 11:48 AM
Please respond to
mark.elsen@gmail.com

To
"DGeorgie@wiley.com" <DGeorgie@wiley.com>
cc
squid-users@squid-cache.org
Subject
Re: [squid-users] How to determine the number of file descriptors for
Squid?

> Hi,
>
> We are running Squid 2.5.STABLE3 version in http accelerator mode on a
> dedicated Red Hat EL 3.0 server.
>
> These are the settings for the size of the cache on the disk and in the
> memory:
>
> cache_dir ufs /spare/squid 7000 16 256
> cache_mem 2 GB
>
> The number of users at the pick is around 2000. We expect the number of
> the users is going to increase in the future significantly.
>
> I wonder if there is any way to estimate the number of file descriptors
> for Squid based on the number mentioned above.
>
> Also, I checked /usr/include/bits/types.h file looking for the
definition
>
> of __FD_SETSIZE. I could not find it. I assume I would need to define
this
>
> variable before compiling Squid. Am I right?
>
> Thanks,
>

  The default (1024 fd´s) should be enough for 2000 users.
  Check cachemgr -> General Runtime Information on info regarding
fd-usage
  and the nuber of spare fd´s.

  If you get lot´s of :

   Warning : Your cache is running out of file descriptors !

 in cache.log. Then you may need to increase them. Check the Squid FAQ
 on how todo this.

 ps: install and use the latest STABLE release.

 M.
Received on Mon Sep 19 2005 - 07:56:07 MDT