AT: Moving Ahead With Amazon EC2 (Intro)

ATAcceptance Testing
I’ve got ten hosts, but their capacity is almost 100% in use by virtual machines. Many of the hosts are obsolete and do not support new configurations. But I am against requesting new hosts.

If you’re part of a big company and need additional IT resources, you probably find you’re required to navigate through a process that includes a substantial amount of person-to-person communication and negotiation. Perhaps you send emails, create an online order or ticket, or simply pick up the phone and discuss your resource requirements. At the other end of the system there’s some manual work involved to approve the request; locate, allocate, and configure the hardware; deal with cables, routers, and firewalls; and so forth. It is not unheard of for this process to take 12–18 months in some organizations! – Host Your Web Site in the Cloud: Amazon Web Services Made Easy by Jeff Barr

To give you an approximate estimation, screwing around with setting up hosts and VMs takes about 40% of development. This is true, of course, if you yourselves are responsible for the quality of what you develop (can there be another way?). I’d like to keep this 40% to play with the test environment, after removing everything supporting virtualization hosts, VMs setup. I mean, I’d like to concentrate solely on research and development, not on virtualization management. Everything in our agile process is good and satisfying, except for this archaic approach to using virtualization. I’ve decided to try using Amazon EC2 as an option to set up the product testing environment…

Amazon EC2 Spot Instances for Acceptance Testing

Using Spot Instances can reduce costs by at least two times as compared with On-Demand instances.
Example:
On-Demand (Large): $0.48 per hour
Spot Instances (Large): $0.20 per hour

Set your maximum price near to the current Spot Price. If the Spot Price goes above your maximum price and your instance is terminated by Amazon EC2, you will not be charged for any partial hour of usage. Just imagin, you have completed the tests in 30 minutes and the instances are termintaed by Amazon EC2. You will get testing for free.

BTW: Do not tell anyone about this;)
Spot Instance
Have requested the large instanse for maximum bid price $0.250. You will often pay less per hour than your maximum bid price. The Spot Price is adjusted periodically as requests come in and available supply changes. Everyone pays that same Spot Price for that period regardless of whether their maximum bid price was higher. You will never pay more than your maximum bid price per hour.