The GlassFish Servlets Layer
The tests mapped to this layer monitors the ability of the GlassFish server to process requests for JSPs and servlets. In the event of a slowdown of one/more web applications deployed on the server, you can use these tests to figure out where the slowdown occurred - while processing requests for JSPs? or while processing servlets? - and also isolate the JSP/servlet that is delaying the processing.
Figure 1 : The tests mapped to the GlassFish Servlets layer