JAVASCRIPT

var socket = io(); reconnect

var socket = io({
  'reconnection': true,
  'reconnectionDelay': 1000,
  'reconnectionDelayMax' : 5000,
  'reconnectionAttempts': 5
});

socket.io reconnect example

io.connect('http://localhost', {
  'reconnection': true,
  'reconnectionDelay': 500,
  'reconnectionAttempts': 10
});