pgpool II, streaming replication and HA

Hi.

I'd like to setup HA PostgreSQL streaming replication cluster with two
nodes. The main issue which I'd like to protect from is HW node failure
or reboot. I supposed to use repmgr to control PostgreSQL cluster and
two pgpool instances as load balancers/DB proxies.

The issue which I still don't understand how to handle is temporary
master failure. Let's say, we have host A (master) and host B (slave).
Now A reboots. Pgpool (or repmgr, doesn't matter) promotes B to master.
Now A comes online (and still considers itself master). How can Pgpool
determine that A host is "bad one" and stop routing queries to A?
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Best regards,
Alexander Pyhalov,
system administrator of Southern Federal University IT department