LN hardware configurations

Several hardware configurations are supported for an LN implementation. These configurations include standalone mode and many variations of client/server mode. Available hardware, data storage requirements, and performance expectations determine the most appropriate hardware configuration.

Standalone mode refers to a configuration where all components of the LN architecture run on a single machine. In standalone mode, an end user can work from the host machine or from a thin client machine, such as an X-Terminal that runs BI. The following figure shows the standalone-mode configuration:

In a client/server configuration, the components of the LN architecture are distributed across two or more machines. Various client/server configurations exist; this section describes the most common configurations.

The simplest client/server configuration is a variation of standalone mode; in this configuration, the application tier, database driver, and RDBMS are on one machine, while the display drivers are distributed among the user workstations. An instance of the application virtual machine and at least one instance of the database driver starts for each user. All users have access to the same application objects and database servers; the following figure shows this configuration:

If two machines are available as servers, two configurations are commonly used. In both configurations, the display drivers reside on the user workstations. In the first configuration, the application tier is placed on one server, while the database driver and the database server are placed on another. As with the previous configuration, an instance of the application virtual machine and at least one instance of the database driver starts for each user.

All users have access to the same application objects and database servers; the following figure shows this client/server configuration. This configuration uses the LN method of client/server access between the application virtual machine and the database server.

An alternative configuration with two servers is to place the applications and the database driver on one server and the database server on another. End user workstations are linked to the machine with the application virtual machine. An instance of the application virtual machine and at least one instance of the database driver is started for each user. All users have access to the same application objects and database servers; the following figure shows this client/server configuration. This configuration uses the RDBMS’s ability to provide client/server access.

You can also use various other configurations of client/server systems, such as dividing the application logic among multiple servers or use multiple servers for distributing the database.