The emergence of Web services is forcing sites to substantially rethink how
existing applications can and should work together.
Previously, considerations about where certain functions should execute
focused principally on the tier. Should the client, the application server,
or the database management system perform this processing? Web services,
however, force the question in a horizontal direction: Which server on this
tier is best suited to handle this processing? And, even more frequently, how
can this application be partitioned intelligently so the right pieces are on
the correct servers? Design tools are responding to these changes with
model-driven architecture and services-oriented application development, two
approaches that capture and represent the salient factors in the design of
loosely coupled, distributed applications.
However, most sites that have co... (more)