Re: how much cpu on a database rac cluster

From: Jack <>
Date: Wed, 5 Sep 2012 08:59:07 +0300
Message-ID: <MSB1s.26027$>

"Mladen Gogala" <> wrote in message
> On Sun, 26 Aug 2012 17:49:25 -0700, dshproperty wrote:
> and we said...
> o do I support this
> nope, not at all. One machine, one host - ONE INSTANCE
> --
> Mladen Gogala

Well, I must say I totally disagree.

One machine, one host -TEN INSTANCE

That is called consolidating. (I am not talking about RAC).

When you have ten systems in ten host the next step is colsolidate those into one host.
CPU consumption is quite similar with ten or one instance (the work does not disabear), and you know cpu-power is cheaper than dedicated manpower. Surely you will need more memory with ten than with one instance, but hardware is very cheap,
 comparing what it is used to be some years(decades) ago. And very other there is different instance for very good reason. We have been running single host with ten intance (very mission critical/operational, but not vldb) many, many years. Management is also simple/better when having control for one business-system per instance.

And into first question:
>Our 3 nodes RAC cluster (Dell, 32 core, hosting 6 databases) is using about
>10 percent cpu during normal business hour. At peak, it use about 30% cpu.
>Did we allocate too much CPU on this box? We are investigating whether it
>is worth the risk of reducing CPU to save money

If your numbers are correct, you could easily test it shutting down one node. See what happens, if about 50% cpu load go for it. Received on Wed Sep 05 2012 - 00:59:07 CDT

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