Log File

A log file is a file to which statistical data is logged. Most web servers are capable of producing statistics. This is usually limited to logging data to a log file. The log file is then analysed using a third-party statistics software package.

Log files are usually compliant with w3c standards. This means that the log files are written in comma-delimited format that can be read by all major statistics software packages. Log files can also be read using a normal text editor. However, this does normally not make much sense; since it is the aggregate information a webmaster would be most interested in, rather then the log file itself. Of course, there are some webmasters that have the habit of regularly looking at log files. This may be a good idea in order to detect potential problems with the web server early.

Log files are used to log a variety of data. Generally, log files log some data for each file request. The data logged by log files includes file type, data sizes, IP address of the requesting server, the exact file location of the file requested and more. Often, it is also useful for the log file to log the referrer of the request. This is the page that links to the website. A log file containing that data can prove invaluable for marketing purposes.

Log files can use up a considerable amount of space, particularly when the web server is very busy. Thus, webmasters often delete old log files after they have been analysed by the stats package. There is really no point in keeping old log files after the aggregate data has been calculated. It is better to keep the aggregate reports, rather than the original log files.