Sizing Openbravo: EC2 cost calculation and experimenting with around 270 concurrent users

To help Openbravo partners and users we have extended our Sizing Tool Guidelines to include some more facts and findings.

"As more the better" --Harpreet Singh ;-)
Same has been proved by the new Amazon Cluster Compute Instance (cc1.4xlarge).

Amazon recently anounced the availability of it's biggest Instance, ideal for cluster infrastructure, as it promises high connectivity between cluster instances (as high as 10 Gigabit Ethernet).
But we tested this instance for the standalone test with Oracle DB and Openbravo on same instance.
The results were realy exciting as it was able to handle around 270 concurrent users.

Now truely speaking "Thats what I call results."
And the same results have been added to our Sizing Tool Results.

"There is no such thing as a free lunch." --Milton Friedman
This instance also has some drawbacks:
- It costs a lot (almost $1.60 per hour)
- Till now it is only available in US (N Virginia) region.
- And is only available with CentOS.

Now here comes another one.
As cost is the biggest concern when we think of any new infrastructure. For example: Running an instance (which can support 10 concurrent users) for 3 (THREE!!!) years on Amazon EC2 would cost only $1217.60, I think these figures can help one think about on-site and in-cloud (EC2) deployments.
So we extended our Sizing Guidelines to help you choose your Amazon Instance.

In the last section of the Guidelines we have added:
- Steps you can follow to calculate your yearly cost with Amazon cost calculator.
- As Amazon calculator is a bit complex so we created simple calculator to help you out.
- And pre calculated cost for most common scenarios.