On Fri, 16 Apr 1999, Cacophonix Gaul wrote:

> I'd like some help with optimizing linux (and apache) 
> for a web benchmark. I understand many of the tunables 
> in /proc/sys,

I've recently updated the documentation for the sysctl
files:
	http://www.nl.linux.org/~riel/patches/

> What should I change at 2.2.5 compile time?

If you want to do an honest benchmark, you should (IMHO)
compile a mostly vanilla kernel...

> Does anyone have any empirical ideas about 
> _specific_ values that would work well for:
> inode-max

Large, really large (like, 8192 or slightly above that)

> bdflush

Set a low number of max dirty percentage and
high syncing times...

> buffermem
> pagecache

Forget these two files, they really don't do much
anymore (or need to, with the new algorithms).

> freepages
> kswapd

Leave at standard value.

> Any other I'm missing ?

If you plan on going into swap, set page-cluster to 5;
if you do a lot of fork()s / exit()s, set pagetable_cache
to something higher...

> I'm using many of the common apache 1.4.3 
> optimizations. Is there anything I can do to improve 
> SMP performance, to help the built in affinity-scheme 
> of linux?

If you're running with 50+ apache processes, processor
affininity isn't going to buy you much. Better make
sure that each Apache child can serve a lot of processes.

And don't do reverse IP lookups with the standard named :)

> The benchmark itself is specweb96, so the files are 
> distributed over a large range of sizes. I expect to 
> see 10K-20K simultaneous active connections.

10k active connections?  Have you found a way to run
this many processes simultaneously?
(is it included in the kernel and did I miss that event
or isn't it integrated yet?)

Rik -- Open Source: you deserve to be in control of your data.
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