Excluded Patterns are useful when it is necessary to disable one or several built-in correlation rules for all future test cases. Autocorrelation sometimes creates extractors for static values that are not required. Almost always, these extractors will not cause issues and, therefore, can be left alone. However, in some rare instances, one such extractor can cause verification failure, which must be disabled. In addition to that, to prevent this extractor from reappearing in future test cases, an excluded pattern has to be created.

Creating an excluded autocorrelation pattern

1. Identify and disable an extractor that is causing the issue.

2. Verify the test case to ensure the problem is fixed.

3. In the extractor tree or test case tree, double-click this extractor to open the extractor editor (a). It will be used to create an excluded pattern.

4. Every value that is matched to the exclusion pattern will be excluded from autocorrelation. Therefore, if the extractor is defined too broadly, some helpful extractors will be disabled. The extractor should be defined narrowly.


Example: The search pattern in the extractor that has to be removed is a regular expression (b) of a 3-rd instance (c) over a GUID (d). Because in future recordings, the response may have more or fewer GUIDs, the occurrence of the GUID that has to be excluded may vary. As a result, the incorrect extractor will be suppressed, which may break future test cases. To increase reliability, define the search pattern more narrowly to find the required value on the first find. In this case, a better approach is to modify the search pattern to extract the formid value (e). Change extractor type to text delimited (f) with text before '&formid=' and text after '&formts' (g).


5. Click the Exclude autocorrelation pattern (h) button to bring up the excluded pattern list (i). A new, excluded pattern (j) will be selected.

6. If necessary, adjust its properties: Name, Page, and Content-Type

7. Click OK to Save

After that, the built-in disabled extractor will be disabled in all future test cases.


Excluded Expressions

In some situations, it may be necessary to stop the auto-correlation of certain groups of values.

For example, all values that begin with "myprefix_" followed by one or more digits must not be autocorrelated.

To prevent StresStimulus from autocorrelation, add the regular expression ^mypref_\d+ to the Excluded Expressions box in Autocorrelation Pattern Editor.

Constant values

The Excluded Expressions box supports constant values (such as constant GUIDs), as well as regular expressions.


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