Over the past few years, our research group at the
St Andrews Cloud Computing Co-Laboratory (StACC) has carried out several case studies looking at the adoption of cloud computing in various organisations.
It seems that the general benefits of using the cloud are well understood by most businesses, however, the costs are much less understood. One reason for this is that the self-service pay-as-you-go pricing models offered by cloud providers is very different to the traditional up-front hardware purchasing options, or the hardware leasing contracts offered by IT vendors.
A problem faced by many businesses is therefore, how do we calculate the costs of using the cloud? What tools are there to help us? To answer these questions, lets take a look at the cloud cost calculators from a few popular cloud providers: Rackspace, Microsoft and Amazon Web Services:
- Rackspace Cost Calculator: A very primitive looking webpage with a slider at the top to resemble memory capacity and a few boxes allowing us to enter the number of servers, running hours, incoming and outgoing bandwidth. A single figure is then displayed at the bottom of the page showing the total cost.
- Microsoft Azure Cost Calculator: A nice looking site with sliders that users can slide up and down to resemble virtual machine instances, databases, storage, bandwidth etc. This results in a single monthly cost figure to go up and down on the right of the screen.
- AWS Simple Monthly Calculator: A more comprehensive calculator that breaks down user requirements into different AWS offerings (on the left) and some example pre-defined deployments (on the right). Once we've entered our requirements, a single figure at the top of the page provides the estimated monthly costs.
So, what is the problem with these tools? Well, a number of problems:
- One of the key benefits of using the cloud is elasticity (AWS named their main offering Elastic Compute Cloud or EC2). However, these calculators completely ignore elasticity during their calculations. We've created the notion of patterns to enable you to see the effects of elasticity on your costs.
- Different providers charge for slightly different things so you have to describe your system in the cloud provider's terms when using their calculator - a major pain.
- You can't easily get the cost of one deployment option, then clone the
deployment, tweak it and compare the costs of the two deployment options.
- Each
cloud provider has its own calculator showing prices in the provider's billing currency, so you'd have to calculate your costs manually if you wanted to use multiple
providers (e.g., deploy your system on AWS EU but backup to Rackspace UK). We've brought the prices from various cloud providers into PlanForCloud and convert them to your preferred currency using live exchange rates.
We believe
PlanForCloud offers a better way of doing cloud cost forecasting. Log in as a guest through
PlanForCloud now.
-- Hassan
