Changes

The proxy process is responsible for monitoring the health of these machines and sounding the alarm if something goes wrong. If the active master appears to be down, the proxy will transparently promote the hot standby and start sending queries to it. When the downed master comes back up, it is demoted to being the new standby.

'''TODO:''' We could use the standby as a read slave, but I don't see the point. In a failure scenario the master needs to be able to handle the entire read load on its own, so it might as well do that all the time.