As I understand it mod_wsgi with Apache will do a code reload when you either touch your WSGI file or do an apache2 reload (that is send it a SIGHUP). The big d

As I understand it mod_wsgi with Apache will do a code reload when you either touch your WSGI file or do an apache2 reload (that is send it a SIGHUP). The big downside there is having my Python code be re-loaded and re-parsed as the new processes get spun up. That usually results in the first few requests being really slow. But it is effectively a zero downtime system. In general, if the components of your stack support being reloaded via SIGHUP instead of having to be restarted, use that. If they do not, consider using different components. However, I'd say that this gets a whole lot easier as you add even a "local" load balancer: that is a load balancer that lives on the same box but does not require a restart during a deploy. In this case you can start up your gunicorn/apache2/uwsgi/whatever on a new internal port, then remap which port is "live" using your firewall or by updating your load balancer's config and reloading it. This is how dokku works with Docker containers and I love that I have zero downtime deploys with it out of the box.