Benchmarks

[William Lovaton]

Hi Chris,

El vie, 30-04-2004 a las 14:09, Chris Davies escribió:
> > > 
> > > 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.

Exactly... once you are cpu bound and have low response under high load
then, your bottleneck is the CPU. You will need more MHz.

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

VM is not a problem for me, with 2GB in RAM and almost 2 months of
uptime it never touched the swap.

The problem seems to be specially network I/O between the web server and
the database server, it seems that there is a little glitch in transfer
speed.  A few months ago we had a serious slowness problem and it was
because de NIC that connects to the DB (for some reason) changed to work
Half Duplex. We were crazy trying to find the problem.

But right now I guess the problem starts to be CPU power.  I'm really
looking forward to Fedora Core 2 and try the new kernel.

I already tried Mandrake 10 in production environtment with a spare
server.  It worked really well from the average load point of view. 
While RH9 2.4.20 was between 12 - 30, Kernel 2.6.3 was between 3 - 9 and
this without TUX. (MDK doesnt ship tux)

The only problem I had was that for some reason network transfer speed
was really really slow and I don't know why.  It was 100Mbps Full Duplex
like the other server.  At the end it didn't work and I had to go back
with the old server.

I was reading the docs in the new TUX version (FC2T2) and saw something
related to network cards.  I posted this mail to the list but I got no
answer:

[] https://www.redhat.com/archives/tux-list/2004-April/msg00012.html

I would be very grateful if you give me some info about that mail.

> 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.

I haven't try that.  I guess that way TUX could be a replacement for
apache.  But not for me, TUX is a threaded web server and that doesn't
make a good combination with PHP if you are using database connections
or some other kind of shared resource.  Besides, some PHP libraries or
modules are not thread safe.


-William