DC/OS Field Notes

When you’re running an app on your cluster and need your stdout and stderr files to be way larger than the standard 2MB, you can use the following lines of code in your JSON app definition file to achieve the larger files:

"env": {
    "CONTAINER_LOGGER_LOGROTATE_MAX_STDOUT_SIZE": "20MB",
    "CONTAINER_LOGGER_LOGROTATE_STDOUT_OPTIONS": "rotate 9",
    "CONTAINER_LOGGER_LOGROTATE_MAX_STDERR_SIZE": "20MB",
    "CONTAINER_LOGGER_LOGROTATE_STDERR_OPTIONS": "rotate 9"
  }

Creating your application/service with this addition will take care of always having tiny files when you actually need nice and big logfiles.

!!NOTE!! always be mindful of using this since it can fill up your filesystem if you don’t pay attention.

Another option would be to change the /opt/mesosphere/etc/mesos-slave-modules/journal_logger_modules.json file to change these settings on a system wide level. I wouldn’t recommend this due to the above risk to run out of diskspace and risking downtime.