Summary

You have walked through an introduction to resource oriented computing and NetKernel from a conceptual perspective.

The section started with a discussion about resources - abstract information that only becomes concrete when it is requested. You learned that resources are identified by logical URI addresses. They are logical because they do not refer to a specific physical location. Only when an address is used in a request is it resolved to a software endpoint. And, an address is resolved each and every time it is used. This means that the physical implementation of a resource can be changed at anytime while a system is running. This late-bound logical coupling permits incredibly flexible systems to be built and updated in running 24*7 installations.

You also learned that underneath the logical layer resides the physical level where actual computing occurs. For each request the URI address is resolved to an accessor which is the software endpoint. It calls on physical level data, objects and libraries to perform its work.

Logical URI addresses are resolved to software endpoints within an address space. NetKernel supports multiple address spaces and these may have relationships between each other.

The task of an architect is to define an application's resources, their address spaces and the transformations that can be applied to them in the business process. With the logical ROC model you focus on the composition of business resources and can step away from the detail of APIs and plumbing.