Re: [GENERAL] Amazon EC2 CPU Utilization - Mailing list pgsql-bugs

From John R Pierce
Subject Re: [GENERAL] Amazon EC2 CPU Utilization
Date
Msg-id 4B633D24.6010407@hogranch.com
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Responses Re: [GENERAL] Amazon EC2 CPU Utilization  (John R Pierce <pierce@hogranch.com>)
List pgsql-bugs
> top is not the be-all and end-all of analysis tools.  I'm sure you
> know that, but it bears repeating.
>
> More importantly, in a virtualised environment the tools on the inside
> of the guest don't have a full picture of what's really going on.


Indeed, you have hit the nail on the head.

does anyone know what the ACTUAL hardware ec2 is using is?   and, does
anyone know how much over-subscribing they do?   eg, if you're paying
for 8 cores, do you actually have 8 dedicated cores, or will they put
several "8 virtual core" domU's on the same physical cores?

OOOOH.... I'm reading http://aws.amazon.com/ec2/instance-types/

As I'm interpreting that, an "XL" instance is FOUR /virtual/ cores,
allocated the horsepower equivalent of 2 1.0 Ghz core2duo style cores
each, or 1.7Ghz P4 style processors.

So we've been WAY off base here, the XL is *FOUR*, not EIGHT cores.
This XL is nominally equivalent to a dual socket dual core 2Ghz Xeon
3050 "Conroe".

Does this better fit the observations?

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