Kevin Murphy just posted Tip of the Day — max_connections and I thought it might be nice to know what people actually set this to so I’ve created a Survey “What’s your max_connections ” (totally anonymous).
For the record, while a consultant the record for a production system was 9,500. Yes you read right, and I might add the client was running a 32-bit OS as well, just to boot.
Apparently they had also tested they could get 9,500 connections, problem is they didn’t do anything with the connections, so didn’t see any per thread memory usage, and I did not get confirmation of how the actually system memory usage was used during the test.