For people less acquainted with the Integration world, the word Bus in “Enterprise Service Bus” causes many to believe that an ESB is something distributed. But on the contrary, 95% of ESB deployments are hub and spoke. One or a few servers located centrally through which all the messages pass. Distributed execution of integration logic remains the exception.
Therefore, we should maybe introduce the “ESH“, the Enterprise Service Hub?
Notes:
- Older integration solutions often had their adapters running on the same servers as the back-end applications or database, so away from the central message broker. But nowadays, also all the adapter logic is put in to the central hub.
- Obviously, every ESB can deployed in a distributed manner, interconnected by some messaging solution. But that’s definitely not the standard approach.
- Why is integration logic put centrally? One justification is to avoid disturbing the servers on which the back-end applications are running.
- Maybe lighter-weight, open source ESB’s will make distributed execution of integration logic more popular. E.g. with such open source ESB’s deployed along with a J2EE application.