var ReplSet = require('./').ReplSet; var replSet = new ReplSet([ { host: '10.211.55.6', port: 31000 }, { host: '10.211.55.12', port: 31001 }, { host: '10.211.55.13', port: 31002 } ], { connectionTimeout: 10000, }); replSet.on('connect', function(_server) { setInterval(function() { _server.command('system.$cmd', { ping: 1 }, function(err, result) { if (err) { console.error(err); } else { console.log(result.result); } }); }, 1000); }); replSet.connect()