Architecture

An installation of an environment with CSP Mobile has the following structure for a JSP Web server:

Web Layer

The Web layer represents the interface between the Web server and the actual application. The JSP technology is used. The JSP files contain Java classes which, in turn, communicate with the application layer.

Each Web client runs in a separate session. The management of these sessions is the responsibility of the Web server. More detailed information on this can be found in the documentation for the appropriate Web server.

The files on the Web layer are very thin components that require very little memory capacity and very little CPU power. The input/output performance is, however, important because the components communicate a great deal.

Application Layer

The application layer is made up of three key components: the management instance (Mobile Engine), a number of work processes (the Mobile Worker processes) and the Chart Worker processes. For each new Web session, the Mobile Engine decides whether to use an existing Worker process or start a new one. The decision is made on the basis of the configuration files (see the section on Configuration).

As soon as the Worker process is running, the Web session connects to the Worker process.

One Chart Worker process is started for each Mobile Worker process. Dynamic charts in the application are generated using this process. A chart is created in the application layer in the Chart Worker process and read out by the servlet ChartReader.

This part requires a significant amount of CPU power, memory and input/output throughput.

Load Distribution

The Application layer can be installed as a master on one machine and also as a slave on any number of other machines. Each slave registers itself with the master. Depending on the settings (see under Configuration), the master decides where a session will be started and thus controls the load distribution.