Adding websites to nginx without restarting nginx

Question

There are many companies that load a web application for you on their servers like say wordpress etc., and since they have other customers on the same server I was curious how they do this w/o having to restart the web server?

If they do restart the web server, it would take down other client sites and that wouldn't be a good situation to be in.

Is it possible with nginx?

Answer 1

/etc/init.d/nginx reload

should reload your nginx config without restarting nginx or making current sites go down

that said, an nginx restart is normally a lot less than 30 seconds so I would be surprised if that was such a big problem

Answer 2

This isn't specific to nginx. You need to gracefully restart it, which means any new workers will use the new config while the running workers use the old config until they finish what they're doing and exit.

http://wiki.nginx.org/CommandLine

Answer 3

You can Load New Configuration Using Signals. It will

1. Read and test a new configuration. If the configuration invalid then do nothing.
2. When valid, start new processing workers with new configuration. Attach new workers to port listening, log, etc.
3. Detach old workers from listeners.
4. Gracefully shutdown old workers.

You can even Upgrade To a New Binary On The Fly. See the same doc.

To perform the reload, send the reload signal:

nginx -s reload