nodejs emitter error

var config = require('./config')
var http = require('http'),
    format = require('util').format,
    url = require('url'),
    db = require('mongoskin').db(config.mongo['host'] + ':' + config.mongo['port'] + '/company_logs?auto_reconnect=true' , {safe:true});

//var emitter = require('events').EventEmitter();
//emitter.setMaxListeners(100);

process.on('uncaughtException', function(err) {
    console.log('Caught exception: ' + err);
    process.exit(1);
});

var UAParser = require('ua-parser-js');
var parser = new UAParser();

var logger = require('./logger');
 logger.debugLevel = 'warn';
 logger.log('info', 'Everything started properly.');
 logger.log('warn', 'Running out of memory...');
 logger.log('error', { error: 'flagrant'});

var handleFavicon = function (req, res) {
        res.writeHead(200, {'Content-Type': 'image/x-icon'} );
        res.end();
        console.log('favicon requested');
        return;
};

var insertErrorLog = function (req, res) {
        var pathname = url.parse(req.url).pathname;
        var ua = req.headers['user-agent'];     // user-agent header from an HTTP request
        var details = parser.setUA(ua).getResult();
        var params = url.parse(req.url,true).query;
        req.collection = db.collection('logs');
        req.collection.insert({
                'category' : params.category,
                'event' : params.event,
                'data' : params.data,
                'type': params.type,
                'timestamp': new Date(),
                'browserName': details.browser['name'],
                'browserVersion': details.browser['version'],
                'osName': details.os['name'],
                'osVersion': details.os['version'],
                'ip': req.connection.remoteAddress,
                'referer': req.headers['Referer'],
                'userAgent': ua
        }, function(err, doc){
                res.end('Data Inserted\n');
        });
};

var notFound = function (req, res) {
        res.writeHead(400, {});
        res.end("<h1>404 - Not Found</h1>");
        console.log('404 - Not Found');
        return;
};

// error_logs
var app = http.createServer(function (req, res) {
        res.writeHead(200, {'Content-Type': 'text/plain'});
        if (req.url === '/favicon.ico') {
                return  handleFavicon(req, res);
        }
        if (req.url.indexOf('/company_logs') >= 0) {
                return insertErrorLog(req, res);
        }
        return notFound(req, res);
}).listen(5000);
app.setMaxListeners(0);

console.log('Server running at localhost:5000/');