MongoDB错误：连接ECONNREFUSED 35.156.235.216:27017

Question

试图将猫鼬连接到我的快速应用程序并出现此错误：

[nodemon] starting `node index.js`
Listening to the port 5000
connect ECONNREFUSED 35.156.235.216:27017

我将应用程序直接连接到MongoDB Atlas，昨天一切正常，但是今天早上我收到了此错误消息。这是数据库连接文件：

const mongoose = require("mongoose");

require("dotenv").config();

const connectDB = async () => {
  try {
    await mongoose.connect(process.env.MONGO_URI, {
      useNewUrlParser: true,
      useCreateIndex: true,
      useFindAndModify: false,
      useUnifiedTopology: true
    });
    console.log("connected to MongoDB..");
  } catch (err) {
    console.log(err.message);
  }
};