The author of this post discusses how to handle multiline log messages in New Relic Logs using custom Fluent Bit configurations on Linux and Windows. The author explains that out-of-the-box functionality provided by the Infrastructure agent is limited, particularly when it comes to parsing and displaying multiline log messages. To overcome this limitation, the author creates a custom Fluent Bit configuration and parsers file to decorate the log with the source file name, output the parsed log with the key name, and use a Regex pattern to mark the timestamp, severity level, and message from the multiline input. The author provides a YAML configuration file that can be used on Linux and Windows platforms, noting that these configs have strict indentation requirements and require spaces instead of tabs. With this custom configuration in place, the author is able to see each multiline message displayed as a single entry in New Relic Logs.