本地Mongoose连接超时和崩溃

Question

我正在着手建立一个非常简单的全堆栈web应用程序，可以处理用户注册和登录。为此，我使用mongoose作为本地数据库来存储用户注册后的信息。这是工作了很长一段时间，但我最近运行了我的应用程序，在一个星期后，它发生了这样的事情：

    MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
    at NativeConnection.Connection.openUri (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/connection.js:845:32)
    at /Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:345:10
    at /Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/helpers/promiseOrCallback.js:31:5
    at new Promise (<anonymous>)
    at promiseOrCallback (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/helpers/promiseOrCallback.js:30:10)
    at Mongoose._promiseOrCallback (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:1135:10)
    at Mongoose.connect (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:344:20)
    at Object.<anonymous> (/Users/hca/Desktop/fullstacksus/server.js:26:10)
    at Module._compile (node:internal/modules/cjs/loader:1102:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1131:10)
    at Module.load (node:internal/modules/cjs/loader:967:32)
    at Function.Module._load (node:internal/modules/cjs/loader:807:14)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:76:12)
    at node:internal/main/run_main_module:17:47 {
  reason: TopologyDescription {
    type: 'Unknown',
    setName: null,
    maxSetVersion: null,
    maxElectionId: null,
    servers: Map(1) { 'localhost:27017' => [ServerDescription] },
    stale: false,
    compatible: true,
    compatibilityError: null,
    logicalSessionTimeoutMinutes: null,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    commonWireVersion: null
  }
}
node:internal/process/promises:225
          triggerUncaughtException(err, true /* fromPromise */);
          ^

MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
    at NativeConnection.Connection.openUri (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/connection.js:845:32)
    at /Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:345:10
    at /Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/helpers/promiseOrCallback.js:31:5
    at new Promise (<anonymous>)
    at promiseOrCallback (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/helpers/promiseOrCallback.js:30:10)
    at Mongoose._promiseOrCallback (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:1135:10)
    at Mongoose.connect (/Users/hca/Desktop/fullstacksus/node_modules/mongoose/lib/index.js:344:20)
    at Object.<anonymous> (/Users/hca/Desktop/fullstacksus/server.js:26:10)
    at Module._compile (node:internal/modules/cjs/loader:1102:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1131:10)
    at Module.load (node:internal/modules/cjs/loader:967:32)
    at Function.Module._load (node:internal/modules/cjs/loader:807:14)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:76:12)
    at node:internal/main/run_main_module:17:47 {
  reason: TopologyDescription {
    type: 'Unknown',
    setName: null,
    maxSetVersion: null,
    maxElectionId: null,
    servers: Map(1) {
      'localhost:27017' => ServerDescription {
        address: 'localhost:27017',
        error: Error: connect ECONNREFUSED 127.0.0.1:27017
            at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1133:16) {
          name: 'MongoNetworkError'
        },
        roundTripTime: -1,
        lastUpdateTime: 57762916,
        lastWriteDate: null,
        opTime: null,
        type: 'Unknown',
        topologyVersion: undefined,
        minWireVersion: 0,
        maxWireVersion: 0,
        hosts: [],
        passives: [],
        arbiters: [],
        tags: []
      }
    },
    stale: false,
    compatible: true,
    compatibilityError: null,
    logicalSessionTimeoutMinutes: null,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    commonWireVersion: null
  }
}
[nodemon] app crashed - waiting for file changes before starting...

作为参考，这是我的server.js文件的一个非常精简的版本：

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

const express = require('express');
const mongoose = require('mongoose');
const app = express();

mongoose.connect(process.env.MONGO_URL, { useNewUrlParser: true, useUnifiedTopology: true, 'useCreateIndex': true });
mongoose.connection.on('error', error => console.log(error));
mongoose.connection.once('open', () => console.log("Connected To Database"));

const indexRouter = require('./routes/index');

app.use('/', indexRouter);

app.listen(3030);

这是我的.env文件:

MONGO_URL=mongodb://localhost/fullstacksus

非常简单，而且，一周前工作得很好。有人知道这是怎么回事吗？谢谢你的回答！

Answer 1

我认为在开始项目之前，您必须运行MongoDB服务器。您可以使用以下任一项（假设您已经在系统中安装了mongodb）。

我将建议您从以下链接https://docs.mongodb.com/manual/administration/install-community/安装mongodb community edition

然后安装后。只需通过以下命令在终端中启动服务

>

Ubuntu

• sudo systemctl start mongod

Windows将环境变量path设置为Mongod.exe后，在终端中运行以下命令。

• 蒙上帝