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22 Web Hosting and Internet Servers
The last few years have been a wild ride in computing. UNIX was the amino acid-laden tidal pool that gave rise to modern client/server computing and the Internet itself. In the 1980s, UNIX established a reputation for providing a high-performance, production-quality networked environment on a variety of hardware platforms. When the World Wide Web appeared on the scene as the ultimate distributed client/server application in the early 1990s, UNIX was there as its ready-made platform, and a new era was born.
Today, there are a variety of Internet-centric services that you might want to “host,” either at your site or at one of the many colocation outsourcing providers.1
In this chapter, we address the three most common services: the web, FTP, and news.
1. The more modern term for a hosting provider is an Application Service Provider or ASP.
22.1 WEB HOSTING
In the early 1990s, UNIX was (literally) the only choice for serving content to the web. As the web’s popularity grew, an increasing number of parties—ranging from advertising agencies to zoos—developed an interest in having their own presence on the net. However, UNIX was a foreign culture to many of these folks.
Seizing the opportunity, companies large and small jumped into the ring with their own server solutions. In many cases, these solutions involved substantial reengineering of operating systems that, unlike UNIX, were not built from the ground up with true preemptive multitasking in mind. Nevertheless, a new industry segment known as “web hosting” or “Internet hosting” was born around the task of serving content to the web. Web hosting servers not only deliver raw web (HTML) pages but also provide supporting services such as FTP, SSL, and streaming audio or video.
These days we have a variety of web hosting platforms to choose from, and a number of specialized web servers have been developed to meet the needs of specific market channels. Microsoft’s once and future flagship product, Windows, has been widely marketed as a web hosting platform. But for folks looking for extreme reliability, maintainability, security, and performance, UNIX is still way ahead of the pack in the web hosting game.
The industry press has published countless articles that ask the question “Which web hosting platform is best?”, usually positioning Windows and UNIX at opposite corners of the ring. Although some of this brouhaha is akin to the “Less filling!” “Tastes great!” battle, there are concrete reasons why UNIX is usually a better choice for production sites.
The foremost advantages of UNIX are its maintainability and performance. UNIX was designed from the start as a multiuser, interactive operating system. On a UNIX box, one administrator can maintain a database while another looks at I/O performance and a third maintains the web server. Under Windows, the person in control of the console (either physically or remotely, using a tool such as PC-Anywhere) is the only one who can perform critical administration tasks. As for performance, a good administrator can tune UNIX to perform two to three times faster than Windows on identical hardware.
22.2 WEB HOSTING BASICS
Hosting a web site isn’t substantially different from providing any other network service. The foundation of the World Wide Web is the Hyper-Text Transfer Protocol (HTTP), a simple TCP-based protocol that’s used to format, transmit, and link documents containing a variety of media types, including text, pictures, sound, animation, and video. HTTP behaves much like the other client/server protocols used on the Internet, for example, SMTP (for email) and FTP (for file transfer).
A web