Amazon RDS - max_connections

My simple question: How can I increase the possible number of connections of my Amazon RDS Database? I used a parameter group where I set

max_connections = 30000

which seems to work on the first hand, as

SHOW VARIABLES LIKE 'max_connections';

returns the expected. But when I run a stress test the monitoring metrics always show a maximum number of 1200 connections. So obviously there have to be other limiting factors, I just don't know. Any help would be highly appreciated.

My test setup: 1 Load Balancer 8 fat EC2 instances (m4.4xlarge) (which is a bit overdimensioned, but I'm still testing) 1 DB: r3.4xlarge with 140 GB memory, 1 TB storage and 10.000 provisioned IOPS

Test: 30.000 virtual users in 10 minutes making 4 requests each (2 reading the DB, 1 writing it, 1 not using the DB). Fails after about two minutes because of too many errors (caused by DB timeouts).

Concerning the hardware this setup should be able to handle the test requests, shouldn't it? So I hope I'm just missing the obvious and there's a parameter which has to be adapted to make everything working.

via Chebli Mohamed