I'd like to use pgbouncer as connection pooler in our productive environment, which consists of six master db server plus 6 slaves and many webserver and services. For example, I'd like to use it as a central point from where I can redirect client connections easily without changing the code on application side. Considering performance issues should I use pgbouncer on one central VM or put it closer to the db server? Do you have some experiences and some hints for a good set up?