Re: FreeBSD 2.1.7.1 and FD_SETSIZE

On Wed 9 Jul, 1997, Richard Preen <rik@netspace.net.au> wrote:
>> Does this mean squid can't use more than 256 FD on a FreeBSD 2.1.7.1 system?
>
>No it doesn't, we are using Squid on FreeBSD 2.1.6 with more than 256 FDs.
>Squid 1.1.8 was changed to stop versions < 2.2 from increasing FD_SETSIZE
>for some unknown reason. You need to modify squid to stop it from doing this.

it was done because, whilst a stock system < 2.2 (and the same applies to most
BSD systems of around that vintage) will allow a large number of file
descriptors per process, select() won't work with larger than 256 (exactly as
the comment said) and Squid will break quite spectacularly.

To fix it, you need to rebuild your *kernel* with a larger FD_SETSIZE in
operation, and then modify that part of the configure script (or diddle the
value in autoconf.h afterwards). It's not the per-process file descriptor
limit that is the problem (if you increase MAXUSERS, you get numbers far in
excess of 1000, anyway.)

James.
Received on Wed Jul 09 1997 - 00:55:20 MDT