What is CSA?
- Client-side aggregation (CSA) is a new method of rendering a WebSphere Portal page that moves the rendering workload from the server to the client. It is made possible with the Representational State Transfer (REST) services introduced in WebSphere Portal 6.1.
- In the traditional server-side aggregation (SSA) rendering, the page and each of the portlets is completely rendered on the server, using JSPs, and returned to the client in one big response.
- In contrast, in the CSA, we request only the pieces of information from the server that are required to update the page as a result of the user’s interactions with the page
- For example, if a page contains four portlets and the user clicks a link in one of the portlets, only that portlet is updated. This means the server must render only one portlet, instead of four portlets plus the theme for an interaction with a single portlet.
- The REST services also take greater advantage of caching. Since each individual artifact can be independently cache-able, the client ends up retrieving a greater number of responses directly out of cache, further reducing the server workload.
