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From "Henri Gomez" <henri.go...@gmail.com>
Subject Re: mod_proxy_balancer/mod_proxy_ajp TODO
Date Thu, 22 Jun 2006 10:02:14 GMT
2006/6/20, Mladen Turk <mturk@apache.org>:
>
> Henri Gomez wrote:
> > Important point in load balancing will be to collect CPU load (job
> > load) from the remote.
> > We often make the mistake to split requests between servers as if it
> > cost the same CPU power (or cpu load) for each of them, but in Java /
> > J2EE some requests could be more CPU/IO/DB consuming than others.
> >
>
> Well, I'm not sure that having the CPU load would mean something.
> For example you might have P3/1GHz and P66/100GHz with the
> same load (close to 80%), and that info in that case would be
> actually misleading. It might help only if your hardware topology
> is exactly the same for all backend servers.
>
> The bussines method OTOH will favor the 100GHz box over 1GHz one,
> thus giving more sense. Even with the same hardware topology,
> it is presumable that the shorter reply timeout would mean less
> CPU cycles used.


Well you we always indicate some sort of CPU power for a remote (a sort of
bogomips) and use this in computation.

But even if your distant box have 10 times more processing power it could
host 20 instances of Tomcats, so the 'TomcatoMips' indicator couldn't be
determined from hardware information collect but should be set and updated
by site admins as they create / remove instances or OS services since if
when you add an SQL server, you loose cpu/io power for your Tomcat
instances)

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