Windows 7 : Controlling and Customizing Your Website (part 5) - Viewing the Server Logs

Viewing the Server Logs

After your web server is chugging along and serving pages to all and sundry, you might start to wonder which pages are popular with surfers and which ones are languishing. You might also want to know whether users are getting errors when they try to access your site.

You can tell all of this and more by working with the IIS logs. A log is a text file that records all the activity on your website, including the IP address and computer name (if applicable) of the surfer, the file that was served, the date and time the file was shipped to the browser, and the server return code (see the next Note box). For each server request, the log file writes a sequence of space-separated values, which makes it easy to import the file into a database or spreadsheet program for analysis.

The log files are stored in the \inetpub\logs\LogFiles\W3SVC1 folder of your Windows 7 system drive. (As you navigate to this folder, you may see one or two dialog boxes telling you that you don’t have permission to open a particular folder. In each case, click Continue and enter your UAC credentials.)

Each filename takes the form u_exyymmdd.log, where yy is the two-digit year, mm is the two-digit month, and dd is the two-digit day. For example, the log for August 23, 2008 would be stored in u_ex080823.log. Figure 8 shows a typical log file.

Figure 8. A typical IIS log file.

At first glance, an IIS log file appears to be nothing but a jumble of letters, numbers, and symbols. However, there’s a bit of method in the apparent madness. First, know that each line (that is, each line that doesn’t begin with #) represents an object that IIS served. This could be a file, and image, or some other content on the website. Second, remember that each field is separated by a space. Third, notice the #Fields line, which appears from time to time in the log:

#Fields: date time s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) sc-status sc-substatus sc-win32-status

					  

This line tells you the name of each log field. To help you make sense of what you’re looking at, Table 1 gives you a summary of what you see in each field.

Server Return Codes

A sc-status code of 200 means the document was sent successfully to the browser. For unsuccessful operations, here’s a summary of some of the return codes you’ll find in the log: