Saturday, December 03, 2005

SCA and Location Coupling

For some reason, I'm fairly obsessed with coupling. I've written a few things on the subject: Dynamic Coupling and A Coupling Index.

I've been monitoring the progress of the IBM/BEA Service Component Architecture for quite some time now. One area of interest to me is the concept of 'spatial' or 'location' coupling (or decoupling, if you prefer).

On many occasions, developers create a model whereby they make an assumption about the caller:
  1. The caller will be local (not incurring network issues)

  2. The caller will be remote (incurring network issues)

In our quest to progress down the decoupling continuum, the issue of 'location assumption' must be addressed. Hence I was quite pleased to see the following text in the SCA whitepaper:

"Components and their service interfaces can be designed for purely local use by other components, or components can be designed for remote access, either from other parts of the business or from other businesses. Local components can use interfaces optimized to exploit the co-location of the service client and the service implementation. Services designed for remote use must take account of the potential for the client being connected over a remote link and so must offer interfaces that are compatible with this remoteness."

I've been wondering... what will end up being a bigger event, the release of SOAP/WSDL or the release of SCA/SDO. Only time will tell.

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