MongoDB持续出现连接超时错误，同款代码昨日可正常连接

针对你遇到的MongoServerSelectionError: connection <monitor> to 18.231.18.253:27017 closed且提示ReplicaSetNoPrimary的问题，结合代码昨日正常运行的情况，按以下步骤排查：

• 检查MongoDB Atlas IP白名单
  当前设备公网IP可能因重启路由器、切换网络等原因发生变化，不在Atlas白名单内。登录MongoDB Atlas控制台，进入对应集群的「Network Access」页面，添加当前设备公网IP，或临时设置0.0.0.0/0（仅测试用，生产环境禁用）后重试。

• 排查网络环境限制
  公司内网、校园网等环境可能屏蔽27017端口，或存在防火墙、代理拦截出站连接。切换到手机热点等不受限网络测试，或检查本地防火墙是否允许Node.js访问外部网络。

• 查看MongoDB Atlas集群状态
  Atlas集群可能临时维护或出现故障，导致无法找到主节点。登录Atlas控制台，查看集群「Overview」页面，确认是否有运行异常或告警。

• 调整连接字符串参数
  增加超时参数延长连接等待时间，同时确保用户名密码已正确替换：

  const uri = "mongodb+srv://<MyUser>:<MyPassword>@cluster0.ot7abmk.mongodb.net/?retryWrites=true&w=majority&connectTimeoutMS=30000&socketTimeoutMS=30000"
  

• 升级MongoDB驱动版本
  mongodb@5.0可能存在已知连接兼容性问题，尝试升级到同大版本的稳定版：

  npm install mongodb@5.9 --save
  

  （注意：5.x驱动要求Node.js版本≥14）

• 完善错误捕获
  在调用run函数时添加错误捕获，便于更清晰定位问题：

  run().catch(err => console.error("连接失败：", err));
  

你的代码片段 #

const uri = "mongodb+srv://<MyUser>:<MyPassword>@cluster0.ot7abmk.mongodb.net/?retryWrites=true&w=majority"
const client = new MongoClient(uri);

async function run(){
    try {
        await client.connect();
        console.log("Connected successfully to server");
      } finally {
        await client.close();
      }
}  

package.json配置 #

{
  "name": "controle-de-gastos-full-stack",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "type": "module",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/G4rutti/controle-de-gastos-full-stack.git"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/G4rutti/controle-de-gastos-full-stack/issues"
  },
  "homepage": "https://github.com/G4rutti/controle-de-gastos-full-stack#readme",
  "dependencies": {
    "mongodb": "5.0"
  }
} 

错误信息 #

MongoServerSelectionError: connection <monitor> to 18.231.18.253:27017 closed
    at Timeout._onTimeout (MyDir)
    at listOnTimeout (node:internal/timers:564:17)
    at process.processTimers (node:internal/timers:507:7) {
  reason: TopologyDescription {
    type: 'ReplicaSetNoPrimary',
    servers: Map(3) {
      'ac-kac6ni2-shard-00-02.ot7abmk.mongodb.net:27017' => [ServerDescription],
      'ac-kac6ni2-shard-00-00.ot7abmk.mongodb.net:27017' => [ServerDescription],
      'ac-kac6ni2-shard-00-01.ot7abmk.mongodb.net:27017' => [ServerDescription]
    },
    stale: false,
    compatible: true,
    heartbeatFrequencyMS: 10000,
    localThresholdMS: 15,
    setName: 'atlas-hqwzt1-shard-0',
    maxElectionId: null,
    maxSetVersion: null,
    commonWireVersion: 0,
    logicalSessionTimeoutMinutes: null
  },
  code: undefined,
  [Symbol(errorLabels)]: Set(0) {}
}

内容的提问来源于stack exchange，提问作者G4rutti