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Product Overview

This chapter explains the role of Netscape Application Server (NAS) within the multitier enterprise environment. In addition, the chapter summarizes the main product components that come with NAS.

This chapter contains the following sections:


The Multitiered Environment
Netscape Application Server is the middleware between enterprise data sources and the clients that access those data sources. Business code is stored and processed on Netscape Application Server (NAS) rather than on clients. An application is deployed and managed in a single location, and the application is accessible to large numbers of heterogeneous clients.

NAS applications run in a distributed, multitiered environment. This means that an enterprise system might consist of several application servers (computers running the Netscape Application Server software), along with multiple database servers and web servers. Your application code can be distributed among the application servers.

Overall, the machines and software involved are divided into three tiers:

The following figure shows a multitiered environment:

End users interact with client software, typically a web browser, to use the application.

NAS handles requests by running the appropriate application code (and accessing data sources if needed). NAS returns the results to the web server, which in turn forwards the reply back to the client.

For more information about the components and interactions in the multitier environment, see the Programmer's Guide.


Product Components
This section describes the software and product components of NAS. This section consists of the following topics:

Programming APIs NAS supports several industry-standard Java APIs. In particular, NAS supports the APIs and technologies as defined by the following specifications:

Note that NAS 4.0 provides full support for JDBC 1.0 and partial support for JDBC 2.0. The supported JDBC 2.0 functionality is described in the Programmer's Guide (Java).

For building application components written in C++, NAS provides the Foundation Class Library. Java application developers can also use the NAS Foundation Class Library to leverage additional capabilities of NAS that are not supported through standard APIs.

For more information about the NAS Foundation Class Library, see the Programmer's Guide or the Netscape Application Server Foundation Class Reference. Both of these documents are available in Java or C++ versions.

For more information about the industry-standard Java APIs that are supported in NAS 4.0, see the appropriate API specification. All specifications are accessible from installdir/nas/docs/index.htm, where installdir is the location in which you installed NAS.

System Services and Application Services System and application services provide a variety of application-level capabilities and system-level capabilities. These services enable the development, deployment, and management of complex business-logic and transaction-based applications.

For more information about these services, see "System Components".

Sample Applications NAS includes sample web-based applications, enabling you to more quickly learn techniques for developing and deploying applications in a NAS environment.

One sample presents a bookstore application that simulates browsing, searching, and ordering books online. This Java application demonstrates the NAS application model that uses industry-standard components such as servlets, JavaServer Pages, Enterprise JavaBeans, and data access with JDBC. For information about installing or using the online bookstore application, see the Installation Guide or the Programmer's Guide (Java).

Another sample presents a banking application that simulates a user session with an online account. This sample demonstrates techniques for migrating existing applications to comply with the industry-standard Java application model. For information about installing the bank application, see the Installation Guide. For details about the application code, see the Migration Guide.

NAS Administrator NAS Administrator is a GUI tool that contains several smaller tools for managing one or more NAS machines or applications. For more information, see "Management Capabilities".For detailed information about using NAS Administrator, see the Administration Guide.

NAS Deployment Manager An application must be deployed before it can be used, and NAS Deployment Manager is a GUI tool that makes application deployment easier. You access this tool either from NAS Administrator or from Netscape Application Builder.

When you deploy an application, NAS Deployment Manager installs all the application's files and registers all of its components on the destination server (a server on which NAS has been installed).

For information about using NAS Deployment Manager to deploy applications, see the Administration Guide.

Netscape Directory Server Netscape Directory Server provides a comprehensive, enterprise-wide directory service for managing information about users, groups, and access control lists. NAS 4.0 includes Netscape Directory Server 4.0, which supports versions 2 and 3 of the Lightweight Directory Access Protocol (LDAP).

For more information, see the NAS Deployment Guide. In addition, consult the Installation Guide for Netscape Directory Server 4.0.

 

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