FRAMINGHAM (01/28/2000) - Definition
Web hosting involves providing, maintaining and managing hardware, applications, content integrity, security and the high-speed Internet connection for a Web site.
At its most basic level, a Web host is either a company that provides Web space for other firms or an organization that hosts its own site. It stores content on server hard drives and makes that content available to users over the Internet.
Users get to the content by entering a Web address, which instructs the underlying protocols of the Internet to find and fetch the home page. Hypertext links on the home page give the visitor passage to other pages within the same site or to other sites.
The two major elements in Web hosting are the network infrastructure and the applications used to operate the Web site, says Joel Yaffe, an analyst at Giga Information Group Inc. in Cambridge, Mass. Physical facilities, site management and security are also important factors, according to large hosting companies such as Digex Inc. in Beltsville, Md., and Exodus Communications Inc. in Santa Clara, Calif.
The core elements of a Web-hosting center include the server hardware, operating system and Web-server application.
Unix has been the preferred operating platform, but Windows NT is becoming increasingly popular, according to Yaffe. The Web sites for New York-based Barnesandnoble.com LLC and Round Rock, Texas-based Dell Computer Corp., which are both e-commerce operations, run on Windows NT. Exodus and others offer both Unix and Windows NT-based server setups.
According to experts, Unix has generally been considered more secure and reliable, but trust in Windows NT as a Web-sever platform has grown stronger during the past couple of years.
A network firewall - sometimes a PC running special firewall software, other times a special integrated hardware and software device - stands between the Web server and the Internet. Although a firewall permits normal traffic between the outside world and the Web server, it doesn't allow unauthorized users outside the firewall to access the content of the Web site.
Without a firewall, an intruder could rework content, steal data or even take up residence and establish a private site on the Web server.
Typically, a Web-hosting center will connect to the Internet via one or more high-speed phone lines, such as a DS3 line that accommodates data transfer rates of up to 45M bit/sec.
The Web server is just one application. Although it can maintain and serve up Web pages and limited amounts of data, it isn't built for handling data-intensive sites such as those with online catalogs containing thousands of model numbers, prices and photos. The same is true for conducting e-commerce or providing interactive chat or streaming audio and video.
In those situations, task-specific applications are required; they generally run on separate computers that are interconnected with the Web servers. The server passes the instructions from the user to the appropriate application.
For example, when a user requests the price of a product, the Web server takes the price that's extracted from the database and presents it as a component on the Web page.
Downtime isn't an option, especially for those who sell over the Web, according to Exodus. Most organizations need their Web sites up and running around the clock. That level of reliability calls for redundancy - Web and application servers that instantly take over should the primary ones fail. It also requires regular backups to ensure data integrity, battery-based uninterruptible power supplies that seamlessly compensate for power grid deviations or brief outages and on-site generators that automatically kick in during a sustained power outage.
But everything going full bore doesn't necessarily mean the Web site will quickly appear when a user enters the site address. When thousands of users simultaneously try to access the same site, it's not unusual for traffic to exceed the capabilities of the servers or the capacity of data lines connecting the servers to the Internet.
When this happens, users get stuck in a virtual queue, waiting for their browsers to download a Web page.
Managing the Site
According to Digex, many large companies outsource their Web sites to hosting companies because those companies offer management services, taking care of security, updating software and providing site-monitoring services.
However, as Web-based applications become increasingly important to a company's business, Yaffe says he expects more large organizations to do their own hosting.
-- Tutorials on how the Web works.www.webproforum.com-- Detailed information about networking and the Internet.www.pugettech.com-- An index and rankings of Web-hosting companies.www.hostindex.com-- Information on site security.www.icsa.net-- All about standards for the Web.www.w3.orgWeb Hosting ConsiderationsFor others to access your organization's Web site at any time, it has to be stored on a Web server that's always connected to the Internet, preferably by a high-speed link. Managing that server, however, involves a number of considerations and an impressive amount of planning and work, so many organizations will want to outsource that to a Web-hosting company. The following are some of the factors that a Web host must take into account:
-- Backup and standby power is needed to keep the site going in the event of a loss of electrical power.
-- Redundant, fault-tolerant servers ensure Web site continuity in the event of the failure of a server box or a hard drive.
-- Redundant telecommunications equipment with alternate communication lines keep your site active if a phone line or router goes down anywhere in the chain.
-- A firewall protects your site from malicious hacking and unauthorized access.