Increase TCP max connections on Mac OS X
Jul 19, 2012Reason
I was trying to benchmark a TCP based file server on Mac OS X. The server is running latest Node.js (0.8.2), while the client to push the server is written in go. ‘Go’ can start thousands of concurrent goroutines easily. I got error when there are hundreds of concurrent clients.
Steps
- increate max open files
$ sysctl -a | grep files kern.maxfiles = 12288 kern.maxfilesperproc = 10240
kern.maxfiles and kern.maxfilesperproc were small numbers, they need to be increased:$ sudo sysctl -w kern.maxfiles=12288 $ sudo sysctl -w kern.maxfilesperproc=10240
after this, you can increase your account’s limit by ulimit -n:$ ulimit -n 10240
- increate max sockets
$ sysctl -a | grep somax kern.ipc.somaxconn: 2048
It was a small number and need to be increased:$ sudo sysctl -w kern.ipc.somaxconn=2048