I am setting up a test environment to simulate a very high load. We have a server farm which is receiving data (cold be thousands of simultaneous users posting data). I currently have max_connections set to 500 and the server is starting ok. If I try to increase the max_connections to 1000, the server is unable to start. I am running a VM with 4GB RAM. Swap space is not being used, and the system is showing about 1.5GB of ram not being utilized.
Are there any other config setting which should be changed together with max_connections to successfully start the postmaster?