performance - node.js concurrent connection limit -


i wrote trivial node.js client/server pair test local limits on concurrent connections. no data sent between them: 10.000 clients connect, , wait.

each time run test, spawn server , 10 clients create 1000 connections each.

it takes little on 2 seconds reach ~8000 concurrent connections. stops. no errors happen (on 'error' callbacks don't fire, close doesn't fire either). connections "block", no result or timeout.

i've raised max file descriptor limit (ulimit -n), , allowed more read/write memory consumed tcp stack via sysctl (net.ipv4.tcp_rmem , wmem).

what's cap i'm hitting? how can lift it?

-- edit --

server program, logging code stripped:

clients = []  server = net.createserver()  server.on 'connection', (socket) ->     clients.push socket  server.listen 5050

client (this runs n times):

sockets = []  [1..num_sockets]     socket = new net.socket     sockets.push socket     socket.connect 5050

these system limits:

sysctl -w net.ipv4.ip_local_port_range="500 65535"   sysctl -w net.ipv4.tcp_tw_recycle="1"                sysctl -w net.ipv4.tcp_tw_reuse="1"                   sysctl -w net.ipv4.tcp_rmem="4096 87380 16777216"    sysctl -w net.ipv4.tcp_wmem="4096 16384 16777216"     sysctl -w fs.file-max="655300"                       sysctl -w fs.nr_open="3000000"                        ulimit -n 2000000


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