Heroku 部署错误连接 ECONNREFUSED 127.0.0.1:27017

如何解决Heroku 部署错误连接 ECONNREFUSED 127.0.0.1:27017

这是我用于 mongodb atlas 连接的代码，它显示连接成功，但稍后当我单击某个选项卡时，应用程序崩溃了。我正在通过 heroku 部署应用程序，我给出了以下错误 .app 在 localhost 上运行良好，但在 heroku 网站上崩溃。它有时允许并打开一些页面，但在那之后立即崩溃，我曾尝试在 heroku 网站上修复环境变量，但这没有帮助，所以我切换到仅通过变量使用 mongo 连接链接。任何帮助表示赞赏。 我发现服务器在恰好 30 秒后抛出无法连接的错误，但仍然无法找到导致错误的原因

if (process.env.NODE_ENV !== "production") {
    require('dotenv').config();
}

const sanitize = require('express-mongo-sanitize');
// const dbURL = process.env.DB_URL;
const session = require('express-session');
const MongoStore = require('connect-mongodb-session')(session);
const dbURL = "mongodb+srv://RohanGupta:****************@*****.****.mongodb.net/oddevegame?retryWrites=true&w=majority";

mongoose.connect(dbURL,{
    useNewUrlParser: true,useCreateIndex: true,useUnifiedTopology: true,useFindAndModify: false
})
    .then(() => {
        console.log("Connected Mongo Successfully")
    })
    .catch(err => {
        console.log("Uh Oh Couldnt connect mongo!!")
        console.log(err);
    })


app.use(methodoverride('_method'));
app.use(express.urlencoded({ extended: true }));
app.use(express.static(path.join(__dirname,'/public')));
app.use(express.static(path.join(__dirname,'/resources')));



app.use(session({
    store: new MongoStore({
        url: dbURL,touchAfter: 24 * 3600
    }),name: "blah",secret: 'this is secret',resave: false,saveUninitialized: false,cookie: {
        httpOnly: true,// secure: true,expires: Date.Now() + 1000 * 60 * 60 * 24 * 7,maxAge: 1000 * 60 * 60 * 24 * 7
    }
}));

2021-06-20T07:27:23.462279+00:00 heroku[web.1]: State changed from starting to up
2021-06-20T07:27:23.230556+00:00 app[web.1]: Listening on PORT 4000
2021-06-20T07:27:23.502833+00:00 app[web.1]: Connected Mongo Successfully
2021-06-20T07:27:53.221633+00:00 app[web.1]: /app/node_modules/mongodb/lib/utils.js:698
2021-06-20T07:27:53.221654+00:00 app[web.1]:           throw error;
2021-06-20T07:27:53.221655+00:00 app[web.1]:           ^
2021-06-20T07:27:53.221655+00:00 app[web.1]: 
2021-06-20T07:27:53.221656+00:00 app[web.1]: Error: Error connecting to db: connect ECONNREFUSED 127.0.0.1:27017
2021-06-20T07:27:53.221656+00:00 app[web.1]:     at /app/node_modules/connect-mongodb-session/index.js:78:17