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Date: Mon, 9 Dec 1996 03:42:25 +1100
From: davidn@sdev.usn.blaze.net.au (David Nugent)
To: angio@aros.net (Dave Andersen)
Cc: mbarkah@hemi.com (Ade Barkah), imb@scgt.oz.au (michael butler),
        jfesler@calweb.com, hackers@FreeBSD.ORG
Subject: Re: Apache and huge numbers of IP's..
References: <199612080242.TAA01291@hemi.com> <199612080408.VAA07389@fluffy.aros.net>
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Dave Andersen writes:
> > > options		"CHILD_MAX=512"
> > > options		"OPEN_MAX=512"
> > 
> > Is this sufficient ? You still have:
> > 
> > #ifndef FD_SETSIZE
> > #define FD_SETSIZE      256
> > #endif
> > 
> > in /usr/include/sys/types.h. FD_SETSIZE ultimately limits the
> 
>    At the beginning of your program, before ALL other #includes, say:
> 
> #define FD_SETSIZE 512

Examining the source for the kernel implementation of select(2)
in sys/kern/sys_generic.c suggests that this won't help. The
kernel would also needs to understand the new FD_SETSIZE for
fd's >= FD_SETSIZE to be seen at that level.

Modifying the define in sys/sys/types.h directly would seem to
be the only way, after which a kernel build/install and make
world would be necessary. And probably rebuild any ports and
extras that use select() as well.

Perhaps FD_SETSIZE should be set higher by default? I'm also
wondering if this might cause transition problems. :-( A more
reasonable default would be 1024 (imho) - this is after all
only 128 bytes in an fd_set block. The problem with virtual
domains is becoming increasingly common and 256 is definitely
too small a value.

Regards,

David Nugent, Unique Computing Pty Ltd - Melbourne, Australia
Voice +61-3-9791-9547 Data/BBS +61-3-9792-3507 3:632/348@fidonet
davidn@blaze.net.au http://www.blaze.net.au/~davidn