Chapter 11: Logging

Overview

You may find it worthwhile to gather data and statistics about the people who visit your site. You can set up logging for your site to help you compile these statistics for your own use. Knowing which pages users visit most frequently can also allow you to customize your site to suit visitors’ needs. The pages used most often can be expanded and supported, while the less accessed pages can be modified to better support users. If a component on the web site is causing a problem, logging can help track it down. Logging also helps you track down malicious users, by logging what pages they access or what File Transfer Protocol (FTP) files they upload or download. IIS provides logging for all its main components: FTP sites, web sites, Simple Mail Transport Protocol (SMTP) virtual servers, and Network News Transfer Protocol (NNTP) virtual servers.

In this chapter, we’ll look at four different types of logging. We’ll cover how to configure logging for your IIS sites and some ways to crunch the data and put it in a meaningful format for your use in examining the who, what, when, and where about people accessing your web site. As for the why—well, you’ll have to get that on your own.

Although, each type of logging has favorable advantages, each does have some disadvantages, too. Both advantages and disadvantages are shown in Table 11-1.

Table 11-1: Log File Advantages and Disadvantages

Log Type	Advantages	Disadvantages
W3C Extended Log File Format	Most logging options and information, most common format. Logs substatus codes.	Can get unwieldy if you choose too many logging options.
Microsoft IIS Log File Format	Comma separated for easy import into other formats.	Non-customizable ASCII format, has only basic info.
NCSA Common Log File Format	Common file format that many web servers use. Compatible with non-Microsoft web server logs.	Non-customizable ASCII format; can't log FTP sites. Very basic information logged.
ODBC Logging	Log information written to database rather than flat file. Can generate reports from data.	Many third-party log file readers don't work with this logging. Doesn't log as much info as extended logging.