Reg Automatic Fail over & Automatic Failback in Pgpool.

Dear group,

I have setup streaming replication setup with two postgresql 9.3
nodes(master-slave).

And also i have configured the pgpool on the two nodes for load balancing
and High availability.

If Primary node goes down then pgpool can able to make the secondry node as
a primary and that is working fine.

What happens after some point of time if the failed primary node comes
back.How can we manage the replication process with this two nodes.(new
primary node and old node primary node)

Can* Automatic failback *is possible in pgpool if yes please send the
scripts and step's required to setup.

Version of Postgres: 9.3

pgpool 3.3.6

What will be down time of database during this procedure?

Thanks For Your Time.

Thanks & Regards,
G V Gurunadh.