Cached clients

A Host On-Demand cached client is any Host On-Demand client whose components have been cached (stored locally for quick access) on the hard disk of a user's workstation. When a user first runs a cached client, the Host On-Demand startup code downloads the Host On-Demand client components and stores them on the hard disk of the user's workstation. This is called installing the cached client.

When the user then runs the cached client, the Host On-Demand startup code downloads only a small startup applet from the server. The startup applet in turn starts the Host On-Demand client from the cached components on the hard disk.

By using the cached client, the user avoids having to wait for the Host On-Demand client components to be downloaded because they are already immediately available on the workstation's hard disk. In addition, the cached client is persistent across operating system restarts and browser reloads. Even though the cached client was originally intended for users with slow connectivity, such as dial-up phone lines, where downloading a large applet would take a long time, many customers have preferred using the cached client even for high-speed lines.

Like all Host On-Demand clients, the cached client is started (both the first time and subsequently) by specifying the URL of a Host On-Demand HTML file in the Address field of a supported Web browser. IBM recommends that you create your own HTML file using the Deployment Wizard. However, you can also use one of the generic, predefined cached client HTML files included with Host On-Demand.

The applet that starts the cached client also determines whether the version number of any of the Host On-Demand client components on the Host On-Demand server is newer than the version number of the corresponding downloaded components. If so, then the applet upgrades the cached client by downloading and caching the newer component from the server before launching the cached client.

The user can install multiple types of a cached client on the same workstation. For example, an emulator cached client, a Database On-Demand cached client, and an administration cached client could all be installed on one workstation. Also, with the Java version of Host On-Demand, the user can install two versions of the same cached client: one with problem determination and one without problem determination.