Logger options for rest_translation_server

Hi,
As we are deploying a chain of servers we want to see what input is actually reaching the xavante server (the ONMT stage of the process). If we add -log_file (path to log file) into the command and set the log level to INFO, the resulting log does not go beyond “Launch server”. I assume we need to insert a _G.logger: info command somewhere to pick up the input lines. Any ideas where?
Thanks.
Terence

We have resolved this with basic io code.