# Match and Update action

This action enables you to update a field based on the contents of other fields. You specify a set of input fields to evaluate. Each input has a corresponding regex tag and an output value. On the first match, the action copies the output value to the output field.

This action provides a simple way to normalize events that have inconsistent formats. Suppose you have multiple event sources that indicate the event class -- application, network, database, etc. -- using different strings in different fields. You can use this action to find a matching string and then update the event class consistently based on the results.

• Input fields

The set of input fields to search.

• Regex tags

Each input field has a corresponding regex tag and output string. On the first match, copy the corresponding output string to the output field.

• Output field

Apply the output string to this field.

## Example

You have two event sources. For one source, "ping" in the description field indicates a network event. For another source, "stored procedure" in the check field indicates a database event. You want to update the class field to either network or database.

Events Before:

{
"description":"ping to cntnr04 > 200ms",
"severity":4,
"source":"cntnr04",
"check":"rtt",
"service":[ "infraTestService"]
}

{
"severity": 5,
"source": "pd4058",
"service":[ "custService"]
}


You set up your action as follows:

• Input fields = description, check

• Regex tags and output strings:

• .*ping.* => network

• .*stored procedure.* => database

• Output field = class

Events After:

{
"description":"ping to cntnr04 > 200ms",
"severity":4,
"source":"cntnr04",
"check":"rtt",
"service":[ "infraTestService"],
"class" : "network"
}

{