What is the relationship between service-oriented architecture and cloud computing? Close siblings, or estranged relatives? As discussed here at this blogsite, some analysts, such as David Mitchell Smith, say SOA isn't necessarily cloud, while others such as Dave Linthicum say a service-oriented foundation is essential for cloud.
SOA-inspired best practices lead to profitable cloud consumption
About the same time, ZapThink's Jason Bloomberg penned this insightful analysis of what is needed to make cloud function profitably, also pointing to the need for architecture. He observes that while IT executives are on board with the promise of cloud computing, they "find themselves lost in the complexities of deployment in a cloud environment." This results in over-reliance on vendors, and you know where that leads.
Architecture is the missing ingredient needed to help cloud computing deliver to the business -- but to date, "cloud architecture" has meant building or buying clouds, not leveraging them. Jason urges moving forward with "Enterprise Cloud Architecture" or "Cloud Consumption Architecture" to achieve business value.
For example, there are three main options for dealing with an existing application that is being considering for a cloud migration: 1) leave the existing app where it is, but extend it by adding new capabilities in the Cloud; 2) migrate the existing app to the cloud, eventually retiring the existing app altogether; or 3) expose the existing app as loosely coupled services, and compose them with cloud-based services that are either already available to you or that you’ve built or purchased for this purpose.
Which is the SOA-ish option? The third one definitely has an SOA-ish ring to it. But the fact of the matter is all three options are part of an SOA approach, Jason points out. SOA practices lay the groundwork for dealing with such issues:
"If your organization has already gone through the rigors of SOA, establishing a governance framework and a business Services abstraction layer, then cloud consumption naturally follows from the best practices you have already been following. Is what you’re doing still SOA? It doesn’t matter."
Jason doesn't see the difference between SOA and cloud implementations, and ultimately, the business doesn't either. Both are about delivering services in a uniform, robust, secure fashion where the enterprise needs them. SOA-enabled services can come from outside or within, so can cloud services.