Web servers and architectures
Today's enterprise Web environments are much more sophisticated than the simple content-delivery model of a few years ago. Evolving Web software technologies and increasing connectivity between Web servers and other data resources continue to revolutionize what users can do from the Internet and the services that businesses can offer and use themselves over the Web.
Today's enterprise Web architectures use what are known as n-tier architectures that enable Web servers to connect to data sources beyond simple static content. To access remote data sources, these n-tier Web architectures typically use middleware, which is the term for software that connects other applications or services. The most powerful and flexible form of middleware is a Web application server, such as IBM WebSphere Application Server, that hosts the application program interfaces (APIs) required by enterprise Web applications. These Web applications implement the connectivity between applications and resources (business logic) required by Web-based implementations of various business processes.
In n-tier Web architectures, an application server can be running on the same system on which a Web server is running or on another system. The Web server acts as an intermediary between Web clients and the application server, just as the application server acts as an intermediary between application logic and remote data requirements.
IBM WebSphere Application Server is a Java application server that is built using open standards such as Java Platform, Enterprise Edition (Java EE), Extensible Markup Language (XML), and Hypertext Transfer Protocol (HTTP)-based Web services. WebSphere Application Server is typically used in conjunction with other IBM products, such as IBM HTTP Server, but can be used with most other Web servers including the standard Apache HTTP Server, Microsoft® Internet Information Services (IIS), and the Sun Java System Web Server. The IBM HTTP Server includes a WebSphere Application Server plug-in to simplify WebSphere configuration and administration.
WebSphere Application Server provides a robust, scalable environment for enterprise Web applications. Its architecture and the reuse and integration opportunities provided by other WebSphere products minimize runtime memory requirements and deliver a secure, standards-based infrastructure for Web-based application development and deployment. The wide range of existing WebSphere add-on products, supported development frameworks, and its support for new standards such as the Service Component Architecture (SCA) satisfy the requirements of today's enterprise applications while simplifying the development and integration of the new applications that will deliver tomorrow's solutions. See Resources for a link to the WebSphere Application and transaction infrastructure page, which provides information about many of the WebSphere add-on products that are currently available.
Both IBM WebSphere Application Server and IBM HTTP Server are supported on many platforms including Linux, IBM AIX®, HP-UX, IBM i (i5/OS, i6/OS, OS/400), IBM z/OS, Microsoft Windows®, and Solaris. See Supported platforms for more detailed information about hardware and software requirements.
See Resources for links to additional information on popular n-tier application servers.
This tutorial discusses installing and configuring IBM WebSphere Application Server 7.0. Version 7.0 is available for and supported on the following operating systems and associated hardware:
- HP-UX on IA64 and HP-UX PA-RISC
- Linux (32 bit)
- Linux for IBM i™, System p™, and System z™
- Sun Solaris on SPARC and x86-64
- Microsoft Windows 2000, Windows Server® 2003, and Microsoft Windows XP
WebSphere Application Server is officially supported on the Red Hat Enterprise Linux versions 4 and 5 and SUSE Enterprise Server versions 9 and 10 Linux distributions, but you should be able to install it cleanly on any Linux distribution. The Setting up unsupported Linux distributions section provides tips to enable you to install and run WebSphere Application Server on Linux distributions other than those that are officially supported.
Note: You can run the 32-bit Intel® architecture versions of WebSphere Application Server and HTTP Server on a 64-bit UNIX system as long as you have installed your UNIX system's 32-bit compatibility libraries on that system. The name of this package and the package management system used for its installation differs on various UNIX systems. On Linux systems, this is the ia32-libs package.
WebSphere Application Server is typically deployed in one of two basic ways:
- As stand-alone application servers that support specific business logic and related applications in single-server environments.
- In a network deployment scenario, where clusters of application servers deliver advanced capabilities for high-performance, high-availability environments. (See Resources for more information.)
As your business requirements and information technology (IT) infrastructure grow, a stand-alone WebSphere Application Server installation can be integrated into the clusters created in a network deployment scenario.
This tutorial focuses on installing a stand-alone application server because of the site-specific nature of network deployments.