Error-detection rules

Application-specific errors

Many application environments have their own error pages that handle problems gracefully.

For example, an application shows an error page when a user enters an invalid password. This page would return a normal HTTP status code of 200.

There is two ways to detect this error:

• Create a custom error condition that looks for the error page by matching its URI stem, because the page is being delivered correctly. You can create a custom error-detection rule to look for that error and measure it.
• Create a custom field that extracts content from the error page. Based on the value of this custom field, the error-detection rule triggers an error or not.

Built-in errors

You might only care about a 404 Page Not Found error only if it affects a container or a document but not a component of a page.

Turn off the system default "not found" error-detection rule and replace it with a more detailed one that looks for "not found" errors on certain types of objects.

Subjective or performance errors

If a PDF file takes more than 2 minutes to download, you might consider this a problem.

Create a custom rule that is triggered when objects ending with .pdf have an end-to-end time longer than 2 minutes.

Interesting events in your web traffic

You might consider a particular user's logging on to be important.

Define an error-detection rule that contains an informational condition to watch for this.