Application tier

The application tier includes the application objects and the LN application virtual machine; together, the application objects and the application virtual machine provide much of the functionality of LN.

The application objects include the compiled LN applications and the data dictionary. The LN applications provide the functionality needed to implement the LN Enterprise Resource Planning (ERP) system.

These applications are written in Baan 3GL or Baan 4GL programming languages supported by the LN Tools package.

The data dictionary defines the data models used by the applications; the data dictionary includes information about the domains, schemas, and referential integrity rules used by LN.

The LN application virtual machine schedules and runs the application objects, sends and receives information to and from the display server, and initiates an instance of the database driver necessary for communication with the database server. A running database driver can support multiple connections to a single RDBMS instance. If an LN installation stores data tables in multiple RDBMS products or instances, the application virtual machine must start one instance of the database driver for each RDBMS product or RDBMS instance with which it must communicate.

The LN application virtual machine is referred to as the LN shell or the bshell. Throughout this document, the virtual machine is referred to as the LN application virtual machine or the application virtual machine.