From http://stackoverflow.com/questions/10164312/node-js-express-js-passport-js-stay-authenticated-between-server-restart?rq=1

Store session between server restart

app.use(express.session({
    secret:'secret',
    maxAge: new Date(Date.now() + 3600000),
    store: new MongoStore(
        {db:mongoose.connection.db},
        function(err){
            console.log(err || 'connect-mongodb setup ok');
        })
}));