>>> I'm wondering a bit about that as many frameworks/libraries that use Postgres already implement an internal connection pool. That's precisely the problem.

>>> I'm wondering a bit about that as many frameworks/libraries that use Postgres already implement an internal connection pool. That's precisely the problem. The usual misconfigured python/ruby application will throw 16 connections at the database. The model for these languages is to deploy one process per core, so there will be 8 concurrent processes running. 8 cores * 16 pool = 256 connections total. Multiply by N parallel servers and that's even more connections. There are issues with large amount of connections and postgresql, hence people decide to put pgbouncer in front of the database to mitigate.