Exception Handling Framework Best Practice

Dear All,

I have got a requirement to build an exception handling framework.
Please suggest the best practices to used.

I was thinking of putting all the logging in a separate log file instead of server.log.
Also i will write only important transactions in db for which i will use UM to publish.

Thinking of using custom error codes as well in order to have a better visibility.

Any reply would be appreciated.

Syed Faraz Ahmed