[pgpool-general: 2709] Using one pgpoll instance per app server?

[Juergen Brendel]

Hello!

I'm very new to pgpool, so please allow me to ask what is probably a
newby question.

I wish to use pgpool just for failover purposes: The DB loads are quite
light, so a single DB server could easily handle them.

However, I don't want pgpool to become a single point of failure. Please
note that I won't be able to do virtual IP address failover in my
particular server environment, so the usual approach (heartbeat + IP
failover) won't be applicable here.

Now I'm wondering whether I could just run one pgpool instance on each
of my appservers (there are 2 or 3 of those), with each appserver
connecting to their local pgpool instance. Each instance would be
configured the same way: Using the same DB server as master, for
example.

Then, if one of my DB servers fails, each pgpool instance would
eventually realize this and start to send their queries to the standby.
However, if one of my pgpool or appserver instances fails, that
appserver simply us out of rotation, which would be clean and neat.

So, I guess it boils down to this question: Can I have multiple pgpool
instances actively accessing the same database cluster (and the same
database) at the same time?

Thank you very much...

Juergen