Current state of this server.
up(1) - Server responding to requests
dead(2) - Server failed to respond
A server is marked dead if it does not respond after
maximum retransmissions.
A server is marked up again either after a waiting
period or if some response is received from it.
The initial value of casState is 'up(1)' at system
re-initialization. This will only transistion to 'dead(2)'
if an attempt to communicate fails.