Benchmarks

[Chris Davies]

On Fri, 2004-04-30 at 12:31, William Lovaton wrote:
> Hi Chris,
> 
> El vie, 30-04-2004 a las 10:42, Chris Davies escribió:
> > > My load average is between 6 and 20 (25 under xtreme load)
> > 
> > load is the average number of jobs in the queue over the last minute,
> > five minutes and 15 minutes.  I have never seen my tux machine get over
> > .8 -- even when serving 60mb/sec.
> > 
> > I don't really think load average is a very good number other than a
> > rough generalization.  I've been on machines where the average is at 1.5
> Load average is a good number to look at.  The thing is that a 1.5 load
> means there are almost 2 processes in execution state.  It doesn't mean

Right, but you can have a low load and be io bound and have a system
that is slow.  or cpu bound and have a system that is relatively
responsive and a high load.

It is one of a few factors to take into consideration.

> > However, hearing that your load is that high, I would say that something
> > is causing you to fork processes frequently.  Does the machine run heavy
> > cgi?
> 
> It runs PHP as an Apache module _not_ as an CGI.  But yeah, it could be
> considered heavy due to the number of users.

then where is the bottleneck?   Something is keeping processes in the
run queue.  IO? VM? 

> > > This is a big enterprise app, highly trasactional.  Right now is serving
> > > 550 concurrent users.
> > Not too bad.  I've got a few machines that apache claims it needs more
> > than MaxClients 1500 -- and no, I don't run keepalive.
> 
> I have MaxClientes 100, very low I know but I dont seem to need more.

that's what tuning is all about.  Finding the right config for each
machine.  We've got a bunch of machines that we manage, and short of a
few defaults to get them started, we spend time watching and figuring
out the traffic to tune them.  

Some of our clients have machines where apache with keepalive would bog
down the machine.  When you have 30-40 images + 1 html + CSS + an
included javascript, you have generally 5x as many connections as actual
users.  Tux handles this incredibly.  Dreamweaver creates quite a need
for Tux on busy sites. haha.

For us, now that I figured out the apache 1.3 problem I was having, it
is a simple drop-in solution.

I'm curious, have you gotten the php4-tux sapi to work?  I've not gotten
the CGI to work, but I think if I can get both CGI and PHP to work with
tux, there won't be much that apache needs to do.