09.26.05
Where the Bus Stops
Who cares about the next big thing? The answer’s obvious, the IT infrastructure we have today will remain in place for a good long while. Paradoxically, that’s why a new technology, Services-Oriented Architectures (SOAs), is advancing past pilot stage across many organizations.
Services don’t replace legacy applications, they expose them and add value in new ways. Log onto FatLens, a concert tickets site, click on Coldplay, and you can find tickets available for the next concert in your area. Beneath the hood, FatLens is making a web services call to eBay for listings and buyer authentication. By contrast, traditional web applications would have forced you to manually navigate hit or miss through portals or search engines.
Services are evolving, just as web applications did a generation earlier.
Back then, Web apps moved from static to interactive. In the process, vendors had to make tough choices. IBM ditched the San Francisco framework once Sun’s J2EE gathered steam. Today IBM sells more J2EE than Sun.
Fast forward. Like FatLens, most services today are manual, where the end user is a human. On the horizon, organizations will find it profitable to daisy chain multiple processes into dynamic workflows where services consume each other. For instance, you might design an app that automatically requests a credit history service as a cost-cutting strategy. But if you’d like to make this a moneymaker, you might refine it to a process designed to stimulate business from your best customers. You would then orchestrate credit checks with policy-driven services also retrieving buying history and generating promotions.
But as you automate, familiar issues arise. Like whether the requestor is entitled to that service, their identity isn’t faked, and that their credit request message hasn’t been corrupted or falsely generated. And as you get serious, you will inevitably deal with quality of service issues, worrying about availability and reliability so your customers do not suffer service interruptions or broken transactions.
Web apps dealt with parallel issues. For them the answer was the appserver, which focused housekeeping in a central middleware stack. But is that the right solution for services which are more self-contained than web requests, where all the logic was deployed back on the server?
That’s where the debate over Enterprise Services Busses (ESBs) arises, because they provide a flatter, more distributed pipeline that can mediate, route, and transform messages – and depending on your viewpoint — orchestrate more complex workflows on demand. In other words, delivering many of the functions of appservers in an environment where services make logic portable and dynamic.
No, you probably won’t rip out your J2EE appservers for ESBs, but as you add services going forward, will you buy appservers or ESBs in the future?
Obviously, ESB pure plays have little to lose by promoting maximum functionality. Regarding incumbents, IBM is playing it both ways. Finally admitting that ESB’s are product (after several years of denial), they will let you buy simple or complex buses. By contrast, BEA is simply selling a simple ESB on the rationale that complex orchestrated actions are best handled by appservers. Our take? BEA is trying to protect its WebLogic business.
Yet, the march of technology could throw many of BEA’s rivals in the same position.
A few months back, Cisco unveiled “application-oriented routing,” moving functions like content routing and message or requestor authentication onto smart routers. It makes sense. As tasks get commoditized, commodity technologies emerge. There’s plenty of precedent: routers replacing custom gateways piles of simple Intel blades supplanting multi-processor servers, and the list goes on.
By that logic, ESBs could find themselves waystops as well, with network devices absorbing repetitive content routing, XML processing, authentication, authorization, and load balancing tasks, while higher-level process design and management devolve to application level. At that point, would the ESB folks be willing to eat their young?