在 Heroku MongoDB 连接上部署应用程序时出错

Question

我使用 express 和 MongoDB 创建了应用程序。当我运行在本地应用程序时，它运行s perfectly.I 在 MongoDB atlas 上创建了一个 PostDB 数据库并生成并获得了连接 string.I 想使用 heroku 部署这个应用程序但我不明白为什么它会 error.Please 帮助我。提前致谢。

这是我的连接字符串：

mongoose.connect("\mongodb+srv://Admin:minnu@mongodb01.irdlb.mongodb.net/PostDB",{useNewUrlParser:true,useCreateIndex:true, useUnifiedTopology: true},function(err,db){
  if (err) {
      console.log('Unable to connect to the server. Please start the server. Error:', err);
  } else {
      console.log('Connected to Server successfully!');
  }});

这是我得到的错误：

2020-07-22T13:10:59.614060+00:00 app[web.1]: commonWireVersion: null
2020-07-22T13:10:59.614061+00:00 app[web.1]: }
2020-07-22T13:10:59.614061+00:00 app[web.1]: }
2020-07-22T13:10:59.631071+00:00 app[web.1]: Unable to connect to the server. Please start the server. Error: MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
2020-07-22T13:10:59.631074+00:00 app[web.1]: at NativeConnection.Connection.openUri (/app/node_modules/mongoose/lib/connection.js:828:32)
2020-07-22T13:10:59.631075+00:00 app[web.1]: at Mongoose.connect (/app/node_modules/mongoose/lib/index.js:335:15)
2020-07-22T13:10:59.631076+00:00 app[web.1]: at Object.<anonymous> (/app/Models/User.js:2:10)
2020-07-22T13:10:59.631076+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:1138:30)
2020-07-22T13:10:59.631077+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
2020-07-22T13:10:59.631077+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:986:32)
2020-07-22T13:10:59.631078+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:879:14)
2020-07-22T13:10:59.631078+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:1026:19)
2020-07-22T13:10:59.631079+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:72:18)
2020-07-22T13:10:59.631079+00:00 app[web.1]: at Object.<anonymous> (/app/Routes/Posts.js:6:12)
2020-07-22T13:10:59.631079+00:00 app[web.1]: at Module._compile (internal/modules/cjs/loader.js:1138:30)
2020-07-22T13:10:59.631080+00:00 app[web.1]: at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
2020-07-22T13:10:59.631080+00:00 app[web.1]: at Module.load (internal/modules/cjs/loader.js:986:32)
2020-07-22T13:10:59.631081+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:879:14)
2020-07-22T13:10:59.631081+00:00 app[web.1]: at Module.require (internal/modules/cjs/loader.js:1026:19)
2020-07-22T13:10:59.631081+00:00 app[web.1]: at require (internal/modules/cjs/helpers.js:72:18) {
2020-07-22T13:10:59.631082+00:00 app[web.1]: reason: TopologyDescription {
2020-07-22T13:10:59.631082+00:00 app[web.1]: type: 'Single',
2020-07-22T13:10:59.631083+00:00 app[web.1]: setName: null,
2020-07-22T13:10:59.631083+00:00 app[web.1]: maxSetVersion: null,
2020-07-22T13:10:59.631083+00:00 app[web.1]: maxElectionId: null,
2020-07-22T13:10:59.631084+00:00 app[web.1]: servers: Map { 'localhost:27017' => [ServerDescription] },
2020-07-22T13:10:59.631084+00:00 app[web.1]: stale: false,
2020-07-22T13:10:59.631085+00:00 app[web.1]: compatible: true,
2020-07-22T13:10:59.631085+00:00 app[web.1]: compatibilityError: null,
2020-07-22T13:10:59.631086+00:00 app[web.1]: logicalSessionTimeoutMinutes: null,
2020-07-22T13:10:59.631086+00:00 app[web.1]: heartbeatFrequencyMS: 10000,
2020-07-22T13:10:59.631086+00:00 app[web.1]: localThresholdMS: 15,
2020-07-22T13:10:59.631087+00:00 app[web.1]: commonWireVersion: null
2020-07-22T13:10:59.631087+00:00 app[web.1]: }
2020-07-22T13:10:59.631087+00:00 app[web.1]: }
2020-07-22T13:11:29.817201+00:00 heroku[web.1]: State changed from starting to up
2020-07-22T13:43:44.978055+00:00 heroku[web.1]: Idling
2020-07-22T13:43:44.980176+00:00 heroku[web.1]: State changed from up to down
2020-07-22T13:43:46.293776+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2020-07-22T13:43:46.385591+00:00 heroku[web.1]: Process exited with status 143
2020-07-22T15:23:20.000000+00:00 app[api]: Build started by user mamadgiaishwarya@gmail.com
2020-07-22T15:23:41.274124+00:00 app[api]: Deploy 9e2202b9 by user mamadgiaishwarya@gmail.com
2020-07-22T15:23:41.274124+00:00 app[api]: Release v9 created by user mamadgiaishwarya@gmail.com
2020-07-22T15:23:41.454375+00:00 heroku[web.1]: State changed from down to starting
2020-07-22T15:23:42.000000+00:00 app[api]: Build succeeded
2020-07-22T15:23:43.755247+00:00 heroku[web.1]: Starting process with command `npm start`
2020-07-22T15:23:46.020199+00:00 app[web.1]:
2020-07-22T15:23:46.020218+00:00 app[web.1]: > ejs-challenge@1.0.0 start /app
2020-07-22T15:23:46.020219+00:00 app[web.1]: > node app.js
2020-07-22T15:23:46.020219+00:00 app[web.1]:
2020-07-22T15:23:46.753513+00:00 app[web.1]: Warning: connect.session() MemoryStore is not
2020-07-22T15:23:46.753525+00:00 app[web.1]: designed for a production environment, as it will leak
2020-07-22T15:23:46.753554+00:00 app[web.1]: memory, and will not scale past a single process.
2020-07-22T15:23:46.770376+00:00 app[web.1]: Server started on port 3000
2020-07-22T15:23:47.305407+00:00 heroku[web.1]: State changed from starting to up
2020-07-22T15:23:48.056394+00:00 app[web.1]: Connected to Server successfully!
2020-07-22T15:23:48.059001+00:00 app[web.1]: Connected to Server successfully!
2020-07-22T15:24:25.538134+00:00 heroku[router]: at=info method=GET path="/" host=shielded-citadel-75286.herokuapp.com request_id=a2276768-c8b4-4937-a8f9-feb2e1cc9d00 fwd="106.200.146.62" dyno=web.1 connect=0ms service=1360ms status=200 bytes=4199 protocol=https
2020-07-22T15:24:26.201469+00:00 heroku[router]: at=info method=GET path="/css/styles.css" host=shielded-citadel-75286.herokuapp.com request_id=1d330f4c-66fd-407c-a8ed-57ba80507318 fwd="106.200.146.62" dyno=web.1 connect=1ms service=9ms status=200 bytes=2179 protocol=https
2020-07-22T15:24:26.284481+00:00 heroku[router]: at=info method=GET path="/images/logo.jpg" host=shielded-citadel-75286.herokuapp.com request_id=96a94f69-2984-4b7f-8e5e-1ae6f12493e6 fwd="106.200.146.62" dyno=web.1 connect=0ms service=11ms status=200 bytes=8897 protocol=https
2020-07-22T15:24:26.318935+00:00 heroku[router]: at=info method=GET path="/images/butterfly.gif" host=shielded-citadel-75286.herokuapp.com request_id=f54f11ef-31a4-4fdf-ad7f-c5d47c354afb fwd="106.200.146.62" dyno=web.1 connect=0ms service=45ms status=200 bytes=687572 protocol=https
2020-07-22T15:24:51.370552+00:00 heroku[router]: at=info method=GET path="/favicon.ico" host=shielded-citadel-75286.herokuapp.com request_id=396f3ab9-b44b-4432-888e-792eb45268e2 fwd="106.200.146.62" dyno=web.1 connect=0ms service=5ms status=404 bytes=394 protocol=https
2020-07-22T15:26:13.000000+00:00 app[api]: Build started by user mamadgiaishwarya@gmail.com
2020-07-22T15:26:35.089490+00:00 app[api]: Release v10 created by user mamadgiaishwarya@gmail.com
2020-07-22T15:26:35.089490+00:00 app[api]: Deploy 7fd231d2 by user mamadgiaishwarya@gmail.com
2020-07-22T15:26:36.000000+00:00 app[api]: Build succeeded
2020-07-22T15:26:36.726907+00:00 heroku[web.1]: Restarting
2020-07-22T15:26:36.741521+00:00 heroku[web.1]: State changed from up to starting
2020-07-22T15:26:37.654962+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2020-07-22T15:26:37.782161+00:00 heroku[web.1]: Process exited with status 143
2020-07-22T15:26:39.941929+00:00 heroku[web.1]: Starting process with command `npm start`
2020-07-22T15:26:42.451886+00:00 app[web.1]:
2020-07-22T15:26:42.451908+00:00 app[web.1]: > ejs-challenge@1.0.0 start /app
2020-07-22T15:26:42.451908+00:00 app[web.1]: > node app.js
2020-07-22T15:26:42.451909+00:00 app[web.1]:
2020-07-22T15:26:43.528332+00:00 app[web.1]: Warning: connect.session() MemoryStore is not
2020-07-22T15:26:43.528343+00:00 app[web.1]: designed for a production environment, as it will leak
2020-07-22T15:26:43.528344+00:00 app[web.1]: memory, and will not scale past a single process.
2020-07-22T15:26:43.537025+00:00 app[web.1]: Server started on port 3000
2020-07-22T15:26:43.977021+00:00 heroku[web.1]: State changed from starting to up
2020-07-22T15:26:44.829130+00:00 app[web.1]: Connected to Server successfully!
2020-07-22T15:26:44.831445+00:00 app[web.1]: Connected to Server successfully!
2020-07-22T15:28:23.000000+00:00 app[api]: Build started by user mamadgiaishwarya@gmail.com
2020-07-22T15:28:45.263212+00:00 app[api]: Deploy c7cbd9d0 by user mamadgiaishwarya@gmail.com
2020-07-22T15:28:45.263212+00:00 app[api]: Release v11 created by user mamadgiaishwarya@gmail.com
2020-07-22T15:28:45.446526+00:00 heroku[web.1]: Restarting
2020-07-22T15:28:45.448387+00:00 heroku[web.1]: State changed from up to starting
2020-07-22T15:28:46.000000+00:00 app[api]: Build succeeded
2020-07-22T15:28:46.651703+00:00 heroku[web.1]: Stopping all processes with SIGTERM
2020-07-22T15:28:46.746865+00:00 heroku[web.1]: Process exited with status 143
2020-07-22T15:28:49.098450+00:00 heroku[web.1]: Starting process with command `npm start`
2020-07-22T15:28:51.924571+00:00 app[web.1]:
2020-07-22T15:28:51.924589+00:00 app[web.1]: > ejs-challenge@1.0.0 start /app
2020-07-22T15:28:51.924589+00:00 app[web.1]: > node app.js
2020-07-22T15:28:51.924589+00:00 app[web.1]:
2020-07-22T15:28:52.898117+00:00 app[web.1]: Warning: connect.session() MemoryStore is not
2020-07-22T15:28:52.898161+00:00 app[web.1]: designed for a production environment, as it will leak
2020-07-22T15:28:52.898162+00:00 app[web.1]: memory, and will not scale past a single process.
2020-07-22T15:28:52.905188+00:00 app[web.1]: Server started on port 3000
2020-07-22T15:28:53.428020+00:00 heroku[web.1]: State changed from starting to up

Answer 1

我认为你的连接字符串有误。

根据 MongoDB docs，连接字符串应以 mongodb:// 开头，而不是前面的前导 \。

我还建议您使用 Promises 或 Async/Await 进行连接，例如下面的代码片段：

    // Start connection via Mongoose.
    mongoose
      .connect(YOUR_CONNECTION_STRING, {
        useNewUrlParser: true,
        useCreateIndex: true,
        useFindAndModify: false,
        useUnifiedTopology: true,
      })
      .then(() => {
        console.log('Database connected successfully!');
      })
      .catch((err) => {
        console.log('Error connecting with error code:', err);
      });
    
    app.listen(PORT, () => {
      console.log('Server starts at port...');
    }

它使代码更易于阅读。

或者，您是否有任何在连接到数据库之前没有捕捉到的异常？出于安全原因，它可能会冒泡并使您的数据库连接崩溃。

在 Heroku MongoDB 连接上部署应用程序时出错

Error while deploying app on Heroku MongoDB connection

node.js

mongodb

express

heroku

mongodb-atlas