The following discussion provides a general overview of Host Integrator. For an overview of each component, see the Host Integrator Components Overview. For information about configuring Host Integrator, see the How To section.
Host Integrator Server consists of the following components:
These components can be used to create and manage custom client/server and web applications that access legacy host data. They communicate with one another over TCP/IP using the WRQ Communications Protocol (WCP).
The diagram below shows a Host Integrator installation in which users access legacy application data using a web browser. Although each component is represented as running on separate machines, more than one component can run on the same machine. It is important to note, however, that although it is possible to run all Host Integrator components on the same machine, this is usually only done for development and testing.
In this type of deployment, a user accesses a web server from a web browser, which in turn starts a script or spawns an application that contacts the Host Integrator Server, which connects to the host. If a change to the web application needs to be made, no change is required to the client. You only need to modify the web application and redeploy it on the server.
Note: In the web application diagram above, the data object is installed on the same machine as the web server and Administrative WebStation. This diagram represents one possible configuration; data objects can reside on separate machines.
Although web applications are the most common way to access Host Integrator Server, you can also create client/server applications. The diagram below shows an installation in which users access host data by running client applications that communicate directly with Host Integrator Server over WCP.
In this type of deployment, the client application on the PC must contain all the logic for accessing the host data, which includes connecting to the Host Integrator Server, requesting the model, providing the user interface between the model and the client, managing the session, and trapping and resolving errors.
In this documentation, the term "session" is a general term that describes a single session between a client or web application and the host. The term "host session" refers to the connection between a Host Integrator Server and the host; host sessions run over Telnet.