This chapter provides an overview of the architecture of the QAD user interfaces. It describes the various components you will install and configure and discusses issues you should understand as you begin to plan your installation.

QAD .NET UI Architecture summarizes the QAD .NET UI architecture:

The QAD .NET UI uses the Tomcat Servlet/JSP container to manage the communication between .NET UI client sessions and QAD Standard Edition. The QAD .NET UI media includes a customized version of Tomcat, which is the recommended version to use. It is installed as part of the installation script.

The QAD .NET UI is installed as a client application under Tomcat. After files are installed, you must configure the UI Connection Manager with installation-specific settings to control and manage the pool of telnet sessions on the telnet server.

Components of the Java Development Kit (JDK) are required by Tomcat.

In a multi-tier environment (see Multi-Tier Installation Overview), when Tomcat is on a different host than the WebSpeed server, you must install the WebSpeed Remote Messenger under Tomcat to support communication with WebSpeed. If you use multiple Tomcat servers, each should have the same version of Tomcat and JDK installed.

The QAD .NET UI provides a user interface for updating and viewing data in a QAD Standard Edition database. QAD Standard Edition must exist in your environment before you begin implementing a UI. This guide assumes you have already installed and configured it.

In addition to the Progress software required for QAD Standard Edition, the QAD .NET UI uses the Progress AppServer.

If you plan to use a UNIX machine for the telnet server, you can use the default telnet service provided with the operating system. If you plan to use a Windows machine for the telnet server, you must use the Georgia SoftWorks telnet server software. This software is included on the QAD UI installation media.

Before you begin, plan where each distributed component will be installed. Make sure that:

Installations are typically performed for multiple environments — pilot, production, training, development, and so on. Each QAD UI system has a unique name, which is reflected in the QAD Standard Edition and Tomcat directory structures:

A list of top-level directories created beneath these directories and a description of their content are found in Installed Components.

Single-Tier Configuration Work Flow summarizes the installation and configuration activities for a single-tier QAD UI environment.

Multi-Tier Configuration Work Flow summarizes the installation and configuration activities for a multi-tier QAD UI environment.

Several deployment options are possible. Two common scenarios are the standard two-tier installation and the isolated database installation.

In a standard two-tier installation, the QAD Standard Edition database server hosts most—if not all—of the system and Progress components. A second server hosts Tomcat and the UI Web application. WebSpeed Messenger must be installed on the Tomcat server.

Another type of two-tier deployment supports a dedicated database server. The installation, compile, and configuration occur on the Tomcat server. This two-tier deployment works well in regulated environments where any change to the database server configuration requires validation.

All user interface and related components are installed and configured on the Tomcat server. Communication between the servers occurs using client networking. A full Progress installation, including WebSpeed, is required on the Tomcat server.

In this arrangement, having the QAD Standard Edition code on the database server is not required, but increases performance for disk-intensive tasks such as MRP and batch processing.