Sometimes, Npgsql users receive errors when working with connection pooling. The problem appears when they try to open a new connection and receive the following message: "Timeout while getting a connection from pool." This is caused when an attempt is made to get a connection from a pool which has all its connections used. Most of the time this problem is a difficult one to track because it generally happens when the system is in production and not in the development phase. Of course. :) Some time ago, I received a report from Miłosz Kubański about such a problem. I told him I would work in a way to get more information so we could check what was happening. In order to help us find the problem, I added a little "hack" to Npgsql: Whenever an error while getting a connection from the pool occurs, Npgsql would log a stacktrace of the allocation of all the connections which were in the pool. Theoretically, those connections which were allocated sho