服务器（节点js）自动终止连接

Question

我正在使用（node js，express）开发一个Web应用程序。在我的本地计算机上，如果我的网站保持不活动状态/没有向服务器发送任何请求，则我保持登录状态。但是在在线部署此应用程序后，如果我没有向服务器发送任何请求，则服务器将在一分钟后终止连接。我已经在代码中尝试了maxage / expire，但是没有任何效果。

这是index.js文件

var express         = require('express'),
app                 = express(),
bodyParser          = require('body-parser'),
passport            = require('passport'),
flash               = require('connect-flash'),
session             = require('express-session'),
LocalStrategy       = require('passport-local').Strategy;

// For sql connection
var connection          = require('./database/connection.js');

// For routes
var loginRoute      = require('./routes/login.js'),
logOutRoute         = require('./routes/logOut.js'),
remainingRoutes     = require('./routes/remaining.js'),
adminRoutes         = require('./routes/adminRoutes.js');

app.use(bodyParser.json({limit: "50mb"}));
app.use(bodyParser.urlencoded({limit: "50mb", extended: true, 
parameterLimit:50000}));
app.use(express.static("public"));
app.set("view engine", "ejs" );
app.use(require('express-session')({
secret: 'sjnsjdcjds',
resave: false,
saveUninitialized: false,
}));
app.use(passport.initialize());
app.use(passport.session());
app.use(flash());


//=============================================
//          ROUTES
//=============================================

app.use(loginRoute);
app.use(logOutRoute);
app.use(remainingRoutes);
app.use(adminRoutes);


//=============================================
//                  SERVER    
//=============================================
app.listen(4000,function(){
    console.log("Welcome to land");
});
//====