Returns a list of the fields that are included in log events in the specified log group. Includes the percentage of log events that contain each field. The search is limited to a time period that you specify.

You can specify the log group to search by using either logGroupIdentifier or logGroupName. You must specify one of these parameters, but you can't specify both.

In the results, fields that start with @ are fields generated by CloudWatch Logs. For example, @timestamp is the timestamp of each log event. For more information about the fields that are generated by CloudWatch logs, see Supported Logs and Discovered Fields.

The response results are sorted by the frequency percentage, starting with the highest percentage.

If you are using CloudWatch cross-account observability, you can use this operation in a monitoring account and view data from the linked source accounts. For more information, see CloudWatch cross-account observability.