I'm setting up a system with 1 App server and 1 DB server, I want to use pgpool's connection pooling features to help ensure site stability and reduce overhead. Should I have pgpool setup on the app or db server for maximum impact?
Depends on the load of each. If the app server has more load than the db then place it on the db server. If the database will be in hyperdrive while the app sits waiting for data, put it app-side.