How to reload the configuration when ever the configuration changed in catalyst web framework and need to reload the configuration with out restarting the catalyst server.
You need to restart the fastcgi instance to reload the Catalyst configuration, as the config is applied at startup time mostly.
For your own application level config, you can make it database based and write your own routine that fetches out of a database periodically.
If you want to restart Catalyst without downtime, you can loadbalance between multiple boxes and restart the fastcgi processes per box (FastCGIExternalServer).
Another solution would be to start up the "new instance" before shutting down the old one, so at all times something accept()-s new requests.
Both of these solutions assume that your configuration changes are not drastic to prevent two instances of the application running beside each other with two different configurations for the duration of the upgrade.