Re:

> On Nov 5, 2018, at 11:25 AM, Pierre Ochsenbein  wrote:
> 
> but on your stdby you have configure a script to become the primary automatically?

Yes, as soon at the CARP address (i.e. the VIP) is migrated to the standby the database is promoted automatically.  All the existing TCP connections are reset/dropped and the clients reconnect to the new server within seconds. 

You have to researched the best solution for your given OS platform.  There are solutions that are platform agnostic too.  I don’t have a canned one to recommend though.