Property configuration in the Data Parser
Configure properties in the Data Parser to change the behavior of an overridden system property of a data source type.
When you override the behavior of a system property, you must provide a valid expression. The string in the Expression field is used to populate system properties by one or more values that are captured from events, and with more formatting characters or injected information. For example, you might want to parse an IP address and a port to combine them both into a string.