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.
The largest I’ve seen is 16,000. And no, they didn’t need that many. They picked that because their application had to serve 10,000 concurrent connections, so they multiplied by “about” 1.5 “just in case”. And they did not listen when I tried to explain to them what a rational setting might be.
(failed the challenge before, 2+3=5, 9+9=eighteen, that failed too. This one is “What is the sum of 6 and 9?” and I put in 15 — let’s hope I’m right!
How this value should be calculated?