Extraction rules priorities

Priorities of extraction rules define which values from the extracted traffic the system uses to populate the fields and which values the system ignores. You can assign a certain priority to only one extraction rule — that is, several extraction rules cannot have the same priority.

Assign the highest priority to the extraction rule that monitors data source that can most reliably populate the field. For example, if user name parameter of the POST command is more authoritative than a cookie, configure the highest rule (ER1) to monitor the user name parameter of the POST command and ER2 rule to monitor cookies.

However, in the case illustrated in the following figure, user name parameter of the POST command does not apply to any object. The value that populates the field is c, which is derived by the ER2 extraction rule.

Applying extraction rules

Notice that c is not the first value that the system associates with the session or page. Values a and b are derived earlier.

Related topic

Verifying content extraction for a custom field