The 'Ins and Outs' of Virtual Domains
Most (if not all) of today's industrial-strength web servers boast the ability to serve "virtual domains," - or multiple domains and IP numbers - from a single computer.
Ordinarily, as explained in the July 2000 Active Insight article on DNS resolution, a single computer with a single IP address assigned to it uses a DNS (domain name system) server to associate a domain name (such as activeconcepts.com) with its IP number.
When that computer has a server program running, a particular directory on that computer's hard drive is designated as the server's "root."
When a user types the computer's domain name or IP number into their browser without specifying a sub-folder, they are directed to whatever files are contained in the root directory (normally a file named "index" or "default").
Thus, the computer's IP number (when it's acting as a web server) denotes not only a particular computer, but also a particular folder on that computer's hard drive.
Using a designated machine for a single web site is the simplest possible hosting arrangement. But if the need arises to host more than one web site on a single server (as is often the case in the web hosting industry), the server's administrator must adopt the use of virtual domains.
In doing this, he or she is effectively telling the server that specified sub-folders within the root should be treated as separate web sites and should respond to requests for their own unique domain names and IP numbers - numbers that differ from the server's true identity.
For example, let's say Bob had a web server which was hosting a single domain (bob.com) at a single IP address (123.456.789.12, which is also the computer's true IP address).
Bob's friend Fred asks Bob to host a web site for him (fred.com). Bob would create a folder inside his server's root called "fred." Without virtual domains, Fred's Internet address would be www.bob.com/fred. But Bob secures an additional IP number (210.987.654.321) and tells his server that requests to the new IP number and "fred.com" are equivalent to requests for Fred's existing address (www.bob.com/fred).
Thus, when a user types "fred.com" or Fred's IP number into their browser, they will be directed to the folder called "fred" in Bob's root folder.
As useful as virtual domains are, they present a unique problem when it comes to producing site usage statistics for a particular domain.
Though a small number of servers are capable of producing an individual log file for each virtual domain, most simply dump all data collected from all domains into a single file.
Without a powerful web analysis tool like Funnel Web, which is capable of splitting the data up by virtual domain and producing an individual report for each site hosted on the server, the data would all be combined in one large but meaningless report.
In the example above, requests for Bob's home page would be shown alongside requests for Fred's home page. Funnel Web, however, is able to automatically detect which requests in the log files pertain to each domain. In fact, it includes several useful options for determining how to classify each request.
You can use the "virtual host" option, which splits up domains based on the domain name referenced in the log file, or you can use "first-" or "second-level directory," which use the directory's position in the root's hierarchy to assign domains. If your server already produces a unique log for each domain it serves, Funnel Web can produce individual reports for each log file presented to it for analysis, sparing you the hassle of analyzing each log separately.
These individual reports can be placed in the appropriate user's domain folder for easy, private viewing inside their own domain by using Funnel Web's "mapping" feature.
For the server administrator, Funnel Web can produce a master report frame from which reports for each sub-domain can be viewed and compared at will. Funnel Web 4.0 can handle up to ten virtual domains per analysis. With Funnel Web Enterprise, the user is free to produce reports for an unlimited number of virtual domains.
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