Architecture

An installation of an environment with CSP Mobile has the following structure for Microsoft IIS:

Web Layer

The Web layer represents the interface between the Mobile server and the actual application. The technology used is ASP.NET. The ASPX pages conceal .NET code, which in turn communicates with CSP Mobile on the application layer.

Each Web client runs in a separate session. The management of these sessions is the responsibility of IIS. Detailed information on IIS can be found in the Microsoft IIS documentation.

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 Configuration for details).

As soon as the Worker process is running, the IIS 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.

The application layer requires a correspondingly large amount of CPU power, memory and input/output throughput.

Distributed Application

The adapter/engine concept enables the Web layer and the Application layer to be separated at the hardware level (multi server). In principle, however, both these instances can be installed on a single computer (single server). This variant should only be used after careful consideration, however (see Planning the Hardware).

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 Configuration), the master decides where a session will be started and thus controls the load distribution.