Any System Administrator will agree that the Internet Information Services log files are an invaluable resource for any Web Server machine, since they are the only built-in tool that allows to effectively keep track of what happens among the web sites and services configured within the system: who requests what, where they are from, and a lot of useful informations regarding our visitors and guests. To see a list of the available info we can collect with the help of this feature, we can visit this official page who documents the W3C Extended Log File Format, which Microsoft adopted since IIS 6.0.
Needless to say, we’re also free to choose what we want to track: we can enable or disable each one of the aforementioned fields by opening the IIS Manager, double-clicking on the Logging and act accordingly, as shown in the screenshot below:
Like we said above, activating the logging feature is not a choice: a good administrator should always keep it enabled for a number of good reasons, including – yet not limiting to – statistical purposes. Just to make a quick example, guess what it could happen if someone tries to use the “file upload” feature available through one of your websites to send banned, restricted, forbidden or copyrighted content: as a result of this the local authority could run an investigation out of your system, which you could easily pass by showing your IIS logs together with a proper explanation of what really happened… unless you turned that feature off to save HDD space!