Most of today’s portal implementations provide a model that facilitates plugging various components (portlets) into the portal infrastructure. Portlets run locally on the portal server, process input data, and render output. A local portlet and a good caching strategy for the content improves the response times, performance, and scalability of portal systems. However, very often we need to access remote Web services. One solution is to use a local portlet to access a remote Web service via its interface, obtain the required results as a raw data stream, and locally render the results in a fragment. This approach is relevant for data-oriented Web services. An alternative solution is to equip the Web service with an additional interface in the form of a portlet. When the Web service is called, it returns the entire portlet instead of raw data. This approach is suitable for presentation-oriented Web services.
On the Properties of a Tree-Structured Server Process