I have two server in master-slave replication.
Yesterday I had a failover and the master-slave roles were reverted.
The new slave was still up and running even if "stale"
The master was definitly running.
The connections to the read-write filter resulted in error:
ERROR 1045 (28000): failed to create new session
In this situation I have no high-availability.
I would expect that in such situation all my connections should be redirected on the running master.