Wednesday, March 26, 2008

TSSJS: SOA without the bus

As you can guess this talk kicks off with the benefits of WS and REST. Early on Brian Sletten states that an ESB (or rather Message bus) should not be used before your architecture is ready for it. I couldn’t agree more.

He then goes on to discuss other approaches. First is a “Pipe and Filters” approach to integration. I do see this style of topology being used with many Mule users.

Second, he talks about the “netpbm” way of integration. I have no idea what this is and preceded to muse over funny Simpson’s episodes. I may have laughed out loud, I can’t be sure. Clown Collage is a truly great episode. Mental note: lookup netpbm.

Next up is the Web and Resource Oriented Architecture (ROA). Rightly so, there is no ESB behind the web, but the web lacks many of the requirements of an ESB such as transactionality, routing (beyond simple forwarding), transformation and centralized management. I am a fan of ROA and REST and view these concepts as more great tools for the Architects toolbox.

The overall message of this presentation was

“hey, don’t forget if you are doing SOA you don’t always need an ESB.”

I do agree with this with the caveat that while you may not use the ESB topology (really, ESB is a deployment topology), but you still need the SOA platform that gives you a way to manage services, and a common set a functions for routing, transformation, management, security, scalability, concurrency, connectivity, etc. These are functions that are always required for any SOA.