Saturday, September 29, 2007

ESB diagramming

Bear with me on my first blog!

On my current project, I recently found myself having to diagram the architecture of an ESB to demonstrate how applications, our own included, would connect to existing services as well as expose services for others to consume. The diagrams were for both developers and managers to understand how the ESB was going to be the 'glue' that integrates existing systems and provide the ability to make composite applications by integrating services in ways only previously imagined.

Typically, I use Visio to diagram and was going to start using UML but felt that it just was too low level. Class diagrams would be way too low level giving a view into one application. Deployment diagrams are great but I don't feel they are able to depict an SOA/ESB environment very well, from a high level, showing multiple services across disparate, distributed systems.

After googling, I found another architect's SOA blog regarding ESB & SOA Visio Stencils. After trying the EAI stencils, I registered for Sonic's ESB Icon and Diagram library stencils. Having read David Chappell's book Enterprise Service Bus several years ago, the blog & Visio stencils re-opened some old, locked brain cells reminding me of how well the book and diagrams depict an ESB architecture. The icons are a little big but can be reduced in size (or the entire picture reduced). If you work with ESBs, in an SOA, or plan to, this book should definitely be part of your personal library!

When needing to drill down into the details of an implementation on the ESB, other diagrams may be better suited (i.e. UML, EAI, BPMN, etc).