Field key in metrics passing the file name.

The field key in the metrics for the log entry content.

This field to store the timestampFromLogLine parsed from the log entry if the log entry has timestampFromLogLine associated.

Field key in metrics indicting if the line is the start of the multiline.If this key is not present, it means the multiline mode is not enabled, we set it to true, it indicates it is a real event, but not part of a mulltiple line.If this key is false, it means the line is not start line of multiline entry.If this key is true, it means the line is the start of multiline entry.

Field key in metrics passing the offset for the current input file.