Hi @Alex Ye I've just had same problem. My solution (a workaround would be more correct though) is following: 1. Create as "passthrough" appender: <appender name="PT"> <encoder> <pattern>%msg%n</pattern> </encoder> </appender> This appender would simply print any message as is without any timestamps or anything like that. 2. Make org.apache.nifi.StdOut and org.apache.nifi.StdErr use that appender like that: <logger name="org.apache.nifi.StdOut" level="INFO" additivity="false"> <appender-ref ref="PT" /> </logger> <logger name="org.apache.nifi.StdErr" level="ERROR" additivity="false"> <appender-ref ref="PT" /> </logger> I think the problem is in RunNiFi class. There is a method that would setup logging handler which would capture anything from System.out and System.err and log them into org.apache.nifi.StdOut/StdErr loggers. Not sure what purpose it has though and I found no way to disable it. ... View more