Mongoose запрос в цикле (Mongoose Trying to open unclosed connection) — как это исправить?

app.get("/dobavit/", function(req, res) {
    for(var i=50; i>0; i--)
{
                InsertAXIXA("analitika",i,function(data){
            });
}
    res.end();
});

function InsertAXIXA(qwerty,page,callback){
    mongoose.connect('mongodb://localhost/gazprom')
    var parsedResults = [];

    var req = request('http://xxx.ru/'+qwerty+"?page="+page, function (error, response, html) {
        if (!error && response.statusCode == 200) {
            //  str = iconv.decode(html, 'utf-8');
            var $ = cheerio.load(html);
            $('.col-1 .col-first').each(function(i, element){
                var buf = $(this);
                var zagolovok = buf.children(0).children().children().eq(0).text();
                var previewText = buf.children(2).children().eq(0).text();
                var url = buf.children(0).children().children().eq(0).attr('href');
                var picUrl = buf.children(1).children().eq(0).children().children().eq(0).attr('src');
          

                var metadata = {
                    zagolovok:zagolovok,
                    previewText:previewText,
                    url:url,
                    typeOfnews:qwerty,
                    picUrl:picUrl,
                    qwerty:qwerty
                };
                var news =new News({
                    zagolovok: zagolovok,
                    previewText: previewText,
                    url:url,
                    picUrl:picUrl,
                    qwerty:qwerty
                    // created_at:Date.today()

                });
                news.save(function(err, news,affected){
               });
                parsedResults.push(metadata);
            });
            callback(parsedResults);
      
        }
        mongoose.connection.close()
    });