How you can reload the configuration whenever the configuration transformed in catalyst web framework and want to reload the configuration without having restarting the catalyst server.
You have to restart the fastcgi instance to reload the Catalyst configuration, because the config is used at startup time mostly.
For your own personel application level config, you may make it database based and write your personal routine that brings from a database periodically.
If you wish to restart Catalyst without down time, you are able to loadbalance between multiple boxes and restart the fastcgi processes per box (FastCGIExternalServer).
Another solution is always to launch the "new instance" before shutting lower that old one, so whatsoever occasions something accept()-s new demands.
These two solutions think that your configuration changes aren't drastic to avoid two cases of the applying running beside one another with two different designs throughout the upgrade.