var cluster = require('cluster'), log4node = require('log4node'); if (cluster.isMaster) { for (var i = 0; i < 4; i++) { cluster.fork(); } var log = new log4node.Log4Node({level: 'warning', file: 'test.log'}); } else { var log = new log4node.Log4Node({level: 'warning', file: 'test.log'}); log.setPrefix("%l %p : "); log.error("Hello, I'm a worker"); setTimeout(function() { process.exit(); }, 100); }