RegEx - using regular expressions

The following are examples of some of the regular expressions you can use throughout AppMon:

  • In Filters: Only show PurePaths that match a certain URI.
  • In Measures: Web request time for URIs matching a certain URI pattern.
  • In Sensor Rules: Instrument methods that match a certain method name.
  • As transformation of a Measure result.

Regular expressions are very powerful and more expensive to analyze than regular string comparisons such as Starts With, Contains, and Ends With. The AppMon Server needs extra CPU to analyze complex regular expressions. This particularly affects PurePath Measures that use RegEx, which can cause extra CPU overhead. A RegEx in a web request count Measure is evaluated for each web request.

Test regular expressions

To test your regular expressions, use the Test Regular Expression dialog box in the same dialog box where you define your regular expression.
Use this dialog box to define the regular expression and a test value, and to find out if the test value matches your regular expression.

Test Regular Expression dialog box
Test Regular Expression dialog box

Test regular group expressions

These are Measures that return a string value that is used as a split value in a business transaction. These provide an optional Transformational Regular expression. For example, if you want to split your user actions by page title, and all your application page titles start with easyTravel, you may want a transformation regular expression that removes the first part of the page title. AppMon requires that you specify a regular expression with a group matching. This returns the individual groups that match.

Use the following dialog box to ensure your transformation regex works as expected.

Test Regular Group Expression dialog box
Test Regular Group Expression dialog box

String comparison options

AppMon offers RegEx and other string comparison options. The following is an overview:

Starts With Matches strings that start with the given value (case sensitive).
Ends With Matches strings that end with the given value (case sensitive).
Match Allows you to use '*' as a placeholder similar to SQL For example, *TEST matches everything that ends with TEST (case sensitive).
Contains Matches strings that contain the given value (case sensitive).
Equals Matches strings that exactly match (are equal) to the given value (case sensitive).

AppMon uses the Java RegEx implementation internally. See the technical reference for more information.