Node.js连接MongoDB报错connect ECONNREFUSED 127.0.0.1:27017求助

问题描述 #

我是MongoDB新手，尝试使用连接字符串mongodb://localhost:27017通过Node.js连接MongoDB时失败，但MongoDB Compass和mongosh命令行工具能正常连接。运行node app.js时出现的错误信息如下：

node app.js
node:internal/process/promises:288
triggerUncaughtException(err, true /* fromPromise */);
            ^

AssertionError [ERR_ASSERTION]: null == MongoServerSelectionError: connect ECONNREFUSED ::1:27017
at Timeout._onTimeout (C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\node_modules\mongodb\lib\sdam\topology.js:292:38)
at listOnTimeout (node:internal/timers:564:17)
at process.processTimers (node:internal/timers:507:7) {
[Symbol(errorLabels)]: Set(0) {},
code: undefined,
reason: TopologyDescription {
commonWireVersion: 0,
compatible: true,
heartbeatFrequencyM...
at C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\app.js:15:10
at C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\node_modules\mongodb\lib\utils.js:349:66 {
generatedMessage: true,
code: 'ERR_ASSERTION',
actual: null,
expected: MongoServerSelectionError: connect ECONNREFUSED ::1:27017
at Timeout._onTimeout (C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\node_modules\mongodb\lib\sdam\topology.js:292:38)
at listOnTimeout (node:internal/timers:564:17)
at process.processTimers (node:internal/timers:507:7) {
reason: TopologyDescription {
type: 'Unknown',
servers: Map(1) {
        'localhost:27017' => ServerDescription {
address: 'localhost:27017',
type: 'Unknown',
hosts: [],
passives: [],
arbiters: [],
tags: {},
minWireVersion: 0,
maxWireVersion: 0,
roundTripTime: -1,
lastUpdateTime: 2313988,
lastWriteDate: 0,
error: MongoNetworkError: connect ECONNREFUSED ::1:27017
at connectionFailureError (C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\node_modules\mongodb\lib\cmap\connect.js:387:20)
at Socket.<anonymous> (C:\Users\kokophone\Documents\MEGAsync\Mystudy\Web\Udemy\Angela Bootcamp\Mgphone One\MangoDB\FruitProject\node_modules\mongodb\lib\cmap\connect.js:310:22)
at Object.onceWrapper (node:events:628:26)
at Socket.emit (node:events:513:28)
at emitErrorNT (node:internal/streams/destroy:151:8)
at emitErrorCloseNT (node:internal/streams/destroy:116:3)
at process.processTicksAndRejections (node:internal/process/task_queues:82:21) {
cause: [Error],
[Symbol(errorLabels)]: [Set]
          },
topologyVersion: null,
setName: null,
setVersion: null,
electionId: null,
logicalSessionTimeoutMinutes: null,
primary: null,
me: null,
          '$clusterTime': null
        }
      },
stale: false,
compatible: true,
heartbeatFrequencyMS: 10000,
localThresholdMS: 15,
setName: null,
maxElectionId: null,
maxSetVersion: null,
commonWireVersion: 0,
logicalSessionTimeoutMinutes: null
    },
code: undefined,
[Symbol(errorLabels)]: Set(0) {}
  },
operator: '=='
}

Node.js v18.12.1

解决方案 #

1. 替换localhost为127.0.0.1 #

将连接字符串改为mongodb://127.0.0.1:27017。问题根源是Node.js的DNS解析优先把localhost映射到IPv6地址::1，但你的MongoDB服务可能只监听了IPv4的127.0.0.1端口，导致连接被拒绝。而Compass和mongosh默认优先使用IPv4，所以能正常连接。

2. 配置MongoDB同时监听IPv4和IPv6 #

找到MongoDB的配置文件（通常名为mongod.conf），修改net模块的配置：

net:
  bindIp: 127.0.0.1,::1
  port: 27017

修改后重启MongoDB服务，服务会同时监听IPv4和IPv6地址，此时用localhost也能正常连接。

3. 修复代码中的错误处理逻辑 #

错误信息里的AssertionError表明代码中可能使用了断言来处理连接错误，这不是标准的错误处理方式。改用try/catch捕获Promise异常：

const { MongoClient } = require('mongodb');

async function connectToMongoDB() {
  const uri = 'mongodb://127.0.0.1:27017';
  const client = new MongoClient(uri);

  try {
    await client.connect();
    console.log('成功连接到MongoDB');
    // 后续数据库操作
  } catch (error) {
    console.error('连接失败:', error);
  } finally {
    await client.close();
  }
}

connectToMongoDB();

4. 检查驱动与服务器版本兼容性 #

运行npm list mongodb查看当前使用的MongoDB驱动版本，确保其与你的MongoDB服务器版本兼容。如果版本不匹配，可通过npm install mongodb@<兼容版本>调整驱动版本。

内容的提问来源于stack exchange，提问作者mgphone