How do you use IIS Failed Request Tracing to identify the root cause of errors?

1 Enable Failed Request Tracing

Before you can use Failed Request Tracing, you need to enable it on your IIS server and on your web site or application. To enable it on your server, open the IIS Manager and select your server node. Then, double-click the Failed Request Tracing Rules icon in the Features View. Click the Enable link in the Actions pane. To enable it on your web site or application, select the site or application node in the IIS Manager and double-click the Failed Request Tracing Rules icon. Click the Enable link in the Actions pane.

2 Create Failed Request Tracing Rules

Once you have enabled Failed Request Tracing, you can create rules that define which requests to trace and what information to capture. To do this, select the site or application node in the IIS Manager and double-click the Failed Request Tracing Rules icon. Then click the Add link in the Actions pane to open the Add Failed Request Tracing Rule wizard. You can then specify options such as the content type, status code range, time taken, event severity, providers and areas, and verbosity level of the request. With these settings, you can ensure that you collect the right data for more effective troubleshooting.

3 View Failed Request Tracing Logs

After you have created one or more rules, IIS will start to generate log files for the requests that match your criteria. The log files are stored in the %SystemDrive%\inetpub\logs\FailedReqLogFiles folder by default. You can change the location and other settings by selecting the server node in the IIS Manager and double-clicking the Failed Request Tracing icon. To view a log file, open it with Internet Explorer or another XML viewer. You will see a summary of the request and a list of events that occurred during the request. Each event has a name, a source, a type, a time, and a data section. You can expand each event to see more details and trace messages.

4 Analyze Failed Request Tracing Logs

To identify the root cause of an error, you need to analyze the log file and look for clues that indicate where and why the error occurred. Check the status code and substatus code of the request to determine what kind of error it is. Additionally, you can check the time taken by the request to see if it was too slow or timed out. Moreover, consider the event severity and trace messages to see if there were any warnings or errors in the modules, handlers, filters, or rules that processed the request. Furthermore, examine the data section of each event to gain more information such as the URL, query string, headers, cookies, session state, or exception details.

5 Fix Failed Request Tracing Errors

Once you have identified the root cause of an error, you can take the necessary steps to correct it. Depending on the source and type of the error, you may need to modify your web.config file, adjust code or scripts for logic errors, install or update components or extensions, alter server resources or performance settings, or contact your hosting provider or network administrator. IIS Failed Request Tracing is a valuable tool that can provide insight into the events and processes that occur during a request. It can help you understand what went wrong and how to fix it, as well as customize it to your needs and preferences by creating and managing your own rules and log files.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?