In my opinion the rage against ESBs is directed more at the term "Enterprise Service Bus" than at the need for integration within an enterprise SOA. Few bloggers would publicly discredit integration infrastructure in the same way that they rebuke the term ESB. Corporate IT portfolios are ripe with IT systems needing to be integrated and line-of-business executives who remain disgruntled with the lack of agility shown by IT in response to their demand for business change. So, if you replace the label "ESB" with the word "integration", I expect that the vitriol would turn to sweet loving respect if not desire.
Integration infrastructure buyers ("ESB" buyers) are learning that most ESBs that come packaged with a platform are really unadorned web service brokers – allowing simple transformations of SOAP messages but little more. If they've done their homework, these same buyers have learned that many vendors re-label security appliances, EAI suites and even application servers as ESBs. So there is little surprise that the term "ESB" itself has become the object of such animosity.
Furthermore, most new SOA infrastructure applications don't need an ESB. ESBs are designed to provide integration between applications and are often overkill when put between services within a single development team. And when real integration projects do arise the complex nature of legacy IT infrastructure makes exceeds the capabilities of these one-size-fits-all service brokers.
Many of the clients with whom I've spoken about integration recognize the vitality of this solution and are on record with their satisfaction:
- Andy Edwardson, Vice President of information technology at FAMI, commented: "In addition to tackling internal integration challenges, our goal is to create a highly available environment in which we can more easily interact with business partners over the Web. Our desire is to develop an enterprise architecture that is less 'hard-wired' and more service-oriented, allowing us to create reusable business objects resulting in a more agile business environment. The Sonic ESB will facilitate such an environment."
- Bruce Hogg, Enterprise Architect for Pacific Blue Cross, commented: "Sonic ESB allows us to leave existing processes in place while layering new business functionality on top, and it allows us to implement a messaging-based distributed infrastructure for migrating to an SOA, step-by-step."
These supporting quotes suggest that some customers have come to draw their own conclusions about what an "ESB" is and as such, support the term - provided that the solution meets their needs (and perhaps is implemented in the right way). It's frustrating that the market has put them in a position where they have to go to such lengths – it makes their job of rationalizing the options available to them that much more difficult. Perhaps in the end, we should admit that the battle of defining ESB properly is a lost cause; rather vendors like Progress focus on SOA integration in general and the value of a robust solution to this age old IT challenge.