Troubleshooting

When determining the source of an issue, there are a handful of avenues one can take while troubleshooting. The following are the most common and accessible options in Django.

DEBUG Mode

Django provides a DEBUG mode, where errors are displayed directly in the frontend (user facing web content) while browsing. This is helpful in that a developer is provided with the source of an error rather than a generic failure page. However, DEBUG mode consumes a significant amount of resources and the outputs publicly display secure information. It is not advised to use DEBUG mode on a production (live) server.

Within medna-metadata, Django’s DEBUG mode can be toggled on (True) or off (False) through the DJANGO_DEBUG environmental setting. For manual installations of medna-metadata, this setting will be set in bashrc and docker/gunicorn.env. For a docker-compose installation, this setting will be set in docker/medna.env.

Logging

Another common method to find the source of an issue that is separate from DEBUG mode, is through log files. medna-metadata stores logs in a few locations:

Django logs - /tmp/
Gunicorn access and error logs - /tmp/
Celery beat and worker logs - /var/log/celery/
PostgreSQL logs - /var/log/postgresql/
NGINX logs - /var/log/nginx/
RabbitMQ logs - /var/log/rabbitmq/

Manual Installation Logs

If services were daemonized during a manual installation, additional information may be available through system status and logs:

# show daemonization status - this shows if a service is running
sudo systemctl status gunicorn
sudo systemctl status nginx
sudo systemctl status celery.service
sudo systemctl status celerybeat.service

# show journal entries for each service
sudo journalctl -u gunicorn
sudo journalctl -u nginx
sudo journalctl -u celery.service
sudo journalctl -u celerybeat.service

# print system logs
sudo cat /var/log/syslog
sudo tail /var/log/syslog -n 40

Docker-Compose Installation Logs

For a docker-compose installation, log file directories are accessible after entering a docker container. To enter the medna-metadata docker container, use the following command:

sudo docker exec -it medna_metadata_web /bin/bash

To exit the docker container:

exit