There's been plenty said over the years in favor of, or in disgust of, enterprise service buses (ESBs). Ganesh Prasad, software architect, Java devotee and Open Source aficionado, has come up with an interesting term for moving ESB approaches into the next decade -- to a new creature called the "enterprise service cloud."
'In the year 2010, we should be doing SOA, not EAI'
The ESC moniker moves with the times, but are we really talking about something more than an ESB? Yes, Ganesh says emphatically. The ESB, he says, "follows a hub-and-spokes model that is more suited to an EAI initiative of the 1990s. In the year 2010, we should be doing SOA, not EAI." That means following a federated approach, not the EAI brokered approach. Plus, it doesn't matter if we're talking about SOAP or REST -- it's all federated, Ganesh says.
The ESB, on the other hand, is tied to the brokered approach, which makes it costly to maintain:
"The ESB is a single point of failure and a performance bottleneck. The normal 'solution' is to beef up the ESB by providing for redundancy and high availability, but this costs a fair bit and only postpones the inevitable.... The correct solution would be to do away with the ESB altogether and embrace the inherently federated model of SOAP (or REST).... In the year 2010, when clouds are all the rage, we should recognize that what SOAP and REST give us are 'service clouds.'"
Ganesh's reasoning is interesting, though we need more details on what an ESC or "service cloud" would look like, how it would be managed and governed, and whether the it would represent a next-gen ESB, or something completely different. Ultimately, SOA is about business transformation by breaking down applications and systems into flexible component services that can be mapped to ever-changing processes. The ESC Ganesh alludes to could be a private or internal cloud that is built on SOA principles.