request hangs somehow about connect-mongostore HOT 4 CLOSED

 ab -c 1 -n 100 -k http://localhost:3005/test.html

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// HERE comes the problem:
var session = require('express-session');
var MongoHttpSessionStore = require('connect-mongostore')(session);

var cookieParser = require('cookie-parser');
app.use(cookieParser());

app.use(session({
        secret: "x",
        //store: new MongoHttpSessionStore(
        //    {
        //        collection: "_sTEST_delete",
        //        db: "test"
        //    }
        //),
        cookie: {
            maxAge: 60000 * 30
        }, // in minute(s) from milliseconds-> *60000
        // the following are both default true
        resave: true,
        saveUninitialized: true
    }
));
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////