Creating an SOA infrastructure for the cloud is a far different challenge than that presented by traditional IT
architectures. No surprises there. But which architectural aspects are most important in defining, modeling, and designing the new SOA infrastructure?
Dr. Chris Harding, Forum Director at The Open Group, says there are two basic vantage points on cloud architecture – that of the cloud supplier and that of the cloud user.
The cloud supplier must determine how to organize its systems to deliver a good cloud service. They must be concerned with things like optimizing the way that different users from the same enterprise actually use the same system. They must also optimize their virtual environment. “Since you are presumably in the cloud business, whether public or private, to make a profit, you can’t afford to have masses of systems that are idle; you want to optimize the use of those systems and appropriately design your virtual environment,” he says.
The other vantage point is that of the enterprises that will use cloud services. Here the options are dizzying. You could use various software-as-a-service (SaaS) sources to meet your applications needs or use a cloud platform to house your own applications. You could also use cloud infrastructure to run both the operating system and the applications. You could have your enterprise IT in the cloud or run some of it in the cloud and some of it onsite.
Each of these options or combinations of options presents its own set of challenges. “It is an extension of the kinds of architectural problems that enterprises already have and discuss within The Open Group,” says Harding.
Service-orientation at work
For Michael Bell, the founder of Methodologies Corporation, a service-oriented architecture modeling firm, based in New Jersey, cloud computing clearly represents the service-oriented era, which has begun in the past decade and is an outgrowth of SOA best practices and standards.
Bell says the term “service” has had a major influence on driving new business initiatives, and galvanizing the development of innovative technologies, such as enterprise service bus (ESB), gateways, and adapters. “Unfortunately, many organizations have not yet recognized the term “service” as the chief contributor to business growth and the rise of institutional productivity,” says Bell. In fact, he suggests, the shift from object-oriented to service-oriented technologies represents a quantum leap in a company’s ability to adapt to change.
Bell says the core success of the cloud computing paradigm is affiliated with service virtualization. So the term “service” is not only affiliated with business imperatives, it is also a dominant part of today’s IT terminology. “Services drive enterprise architecture and application architecture initiatives. A service embodies business processes and yet represents a major change in the way we think about technology,” says Bell.
In addition, Bell notes that the term “service” has had a major influence on driving new business initiatives, and galvanizing the development of innovative technologies, such as the ESB, gateways, and adapters.
Indeed, Harding says the ESB is one of the most important specific components that designers can use in their enterprise architecture. Harding says that only a few years ago many people were questioning whether an ESB was essential to SOA. “In theory, the answer was no but in fact it does seem to be a very useful device and yes, I think it will be an important aspect of SOA-Cloud architecture going forward,” says Harding. Still, he says, there are a number of questions to be resolved as to how that will be done.
Cloud computing is really just starting to take off and in the year ahead I think we will see people trying a lot of different things, he adds.
For those wishing to be “cloud ready,” Harding suggests starting with adoption of SOA architecture and then moving on to develop a clear understanding of all the different aspects of cloud and the merits of each.
“It might be wise to do a pilot project right away but if you are planning to make it part of your architecture right off, you are putting a big part of your business at risk,” says Harding. What’s more, he notes, it is wise to continue to revisit your ROI expectations. “You can’t just assume that cloud is wonderful, you must calculate what it will cost,” he says.