Lots of distributed object, SOA, Web, Web services talk going on recently …
Dare Obasanjo on Web/SOA;
What Don and the folks on the Indigo team are trying to do is apply the lessons learned from the Web solving problems traditionally tackled by distributed object systems.
I know they’re trying to do that, but what they’ve (and most nearly everybody else) have missed, is that the Web is already a distributed object system; it has its own way of addressing most of the problems that previous attempts at distributed object infrastructures attempted to solve. For the things it doesn’t address, Web extensions like the Semantic Web and ARREST cover them … and then some.
James Robertson on HTTP, documents and coupling;
Here’s my point though. It’s magic thinking to say that you have looser coupling simply because you use Http transport and XML documents. It’s a fantasy. Why do I say that? Well, let’s posit a blog server that accepts XmlRpc formatted posts. There you go – http transport, xml documents.
HTTP isn’t a transport protocol. It’s not intended to send RPC messages, it’s intended to send real documents like images and resumes and letters and purchase orders and … anything that is serialized state. If you use it that way, then there is magic there, because it gets data into the hands of somebody else’s application code, rather than into the hands of some infrastructure code.
It’s actually no different than CORBA – except that maybe it’s slower. Either way, I have a server listening on a port, expecting data in a given form, and able to perform a constrained set of actions if I send it the right requests – and ready to send back errors if I don’t.
CORBA only tells you that objects have interfaces. HTTP tells you what that interface is.