The cloud-SOA connection

Cloud computing may have overtaken SOA as the trendy technology term du jour, but the two concepts can be paired to bolster service deployments, industry experts say. With cloud computing, enterprises can access services hosted on third-party servers over the Internet. In SOA, enterprises use integrated application services in a more lightweight fashion than traditional application platforms.

Recently, analyst Anne Thomas Manes of the Burton Group wrote a controversial “obituary” for SOA, panning the acronym, while still endorsing the need for service-oriented architecture. SOA, she said, was survived by “offspring,” including cloud computing, BPM, mashups, and SaaS.

“Certainly, the SOA conversation is starting to shift to the cloud,” says Steven Martin, senior director for developer platform technology at Microsoft. “The cloud is a logical hosting environment for services,” he says. “Service orientation is a way to build applications, whereas 'cloud' refers to the infrastructure as well as the delivery model for that application.”

“SOA is an architectural style for building applications, loosely coupled, allowing composition,” says Jerry Cuomo, CTO of IBM's WebSphere business. “Can we build a datacenter infrastructure on SOA principles? Yes, and that's the cloud, so it's a service-oriented infrastructure,” he adds. “It's taking that architectural principle of SOA and applying it to an infrastructure.”

Adopting SOA can prepare an enterprise for cloud computing, says Tim Hall, director of SOA products for Hewlett-Packard's software group, by showing what challenges an organization faces internally in supporting service components — challenges that using cloud services will exacerbate. The service orientation in SOA and the cloud make for similarities, he says, such as both concepts requiring a governance layer and a strong understanding of processes.

Both the cloud and SOA determine what are some of the major reusable components and what are the right technologies to run large-scale components over open networks, says Rob Helm, director of research at Directions on Microsoft. An organization that has moved toward SOA in a modular fashion is in a better position to move modules to the cloud, he notes.

The cloud serves as a good way to deploy services in an SOA environment, says Sanjiva Weerawarana, CEO of open source SOA software vendor WSO2. He notes that SOA and the cloud support each other, but are not based on the same ideas: “Cloud computing is a deployment architecture, not an architectural approach for how [to] architect your enterprise IT [as SOA is].”

SOA could have a role to play in the integration of cloud applications back into legacy systems, says Lew Tucker, Sun Microsystems' CTO for cloud computing. (Sun plans to unveil its cloud plans on March 18.)

Another connection between SOA and the cloud is the enhanced buildup of the terms, Hall says. “People overhype it and then it goes through [a period] of disillusionment,” he notes — something that has already happened to SOA. Afterward, a technology is used in a more pragmatic fashion.