Q. How much will it cost me to run my application in the Windows Azure cloud platform?

A. The anwer, of course, depends on what you are doing. Official pricing information is available on the Windows Azure Pricing site, and to help you model pricing for your application you can check out the latest Windows Azure Pricing Calculator. Also, the Microsoft Assessment and Planning (MAP) Toolkit is now in beta.

Simple cost example: Running One Instance of a Small Compute Role costs 12¢ per hour, which is around $1052 per year. A SQL Azure instance that holds up to 1 GB costs $9.99 per month. If you have Two Small Compute Instances & 1 GB of SQL Azure storage, plus throwing in some bandwidth use, a dash of Content Delivery Network (CDN) use, and your baseline cost might start at around $2,225.

Update 22-June-2011: The pricing calculators may not reflect this interesting development: data transfer into the Azure Data Centers becomes free on July 1, 2011. See: https://blog.codingoutloud.com/2011/06/22/free-data-transfer-into-azure-datacenters-is-a-big-deal/ and http://blogs.msdn.com/b/windowsazure/archive/2011/06/22/announcing-free-ingress-for-all-windows-azure-customers-starting-july-1st-2011.aspx

But it is not always that simple: this is just the simplest, pay-as-you-go model! In the short term, there are many deals, offers, and trials – some free. There are Azure benefits included with MSDN. And long term there are ways to get better rates if you have an Enterprise Agreement with Microsoft, or by selecting a more predictable baseline than pay-as-you-go. See the Windows Azure Pricing site for current options.

Further, when comparing costs with other options, consider a few factors:

• The SQL Azure storage is really a SQL Azure cluster of three instances giving you storage redundancy (3 copies of every byte), high availability (with automagic failover), high performance, and other advanced capabilities.
• Similarly, every byte written to Windows Azure Storage (blobs, tables, and queues) is stored as three copies.
• Running two Small Compute instances of a role comes with a 99.9% uptime Service Level Agreement (SLA), and a 99.95% connectivity SLA. Read more about the Compute, SQL Azure, and other Windows Azure Platform SLAs here.
• Since Windows Azure is Platform as a Service (PaaS), be careful to also consider that you may have fewer hassles and lower engineering and operational costs – these are lower staff-time costs – if you are comparing to an Infrastructure as a Service (IaaS) offering.

While you are at it, consider checking out some of these related third-party offerings:

• CloudValue – A whole company dedicated to understanding and optimizing costs in moving to the cloud. I saw them at TechEd Atlanta in May 2011. They (a) presented a generally useful talk on Cost-Oriented Development (not specific to their technology, though we saw a glimpse of their Visual Studio integrated cost analyzer); and they (b) had a booth so people could check out their CloudValue Online Service Tracking (COST) service which provides ongoing analysis of your costs in the Windows Azure cloud. I am trying out the COST product now that my beta request has been approved!
• CloudTally – A service offering from Red Gate Software – currently in beta, and currently free – will keep an eye on your SQL Azure database instance and based on how much data you have in it over time, it will report your daily storage costs via email. I’ve been using this for a few months. The data isn’t very sophisticated – of the “you spent $3.21 yesterday” variety – but I think they are considering some enhancements (I even sent them some suggestions).
• Windows Azure Migration Scanner – An open source tool created by Neudesic to help you identify changes your application might require in order to make it ready for Azure. This is not specifically a cost-analysis tool, but is useful from a cost-analysis point of view since it can help you predict operational costs of the Azure-ready version of your application – for example if you will make changes to leverage the reliable queue service in Windows Azure Storage, you will know enough to model this. Read David Pallmann’s introduction to the scanner, where he also mentions some other tools.
• Greybox – While not a core tool for calculating costs, it is a interesting open source utility to help you avoid the “I-deployed-to-Azure-for-testing-purposes-but-forgot-all-about-it” memory lapse. (If deployed, you pay – whether you are using it or not. Like an apartment – you pay for it, even while you are at work – though Azure has awesome capabilities for you to “move out of your cloud apartment” during times when you don’t need it!) You may not need it, but its existance illustrates an important lesson!

Credit: I discovered the new Windows Azure Pricing Calcular from http://twitter.com/#!/dhamdhere/status/73056679599677440.

Is this useful? Did I leave out something interesting or get something wrong? Please let me know in the comments! Think other people might be interested? Spread the word!