VPS环境下Node.js后端无法连接MySQL数据库求助

我正在开发一款基于Node.js后端+MySQL数据库的Flutter聊天应用，本地开发环境一切正常，但部署到VPS后，Node.js代码无法连接MySQL，报错ETIMEDOUT，服务器日志显示SequelizeConnectionError连接超时。以下是相关信息，恳请帮忙排查：

报错日志 #

Unable to connect to the database: { SequelizeConnectionError: connect ETIMEDOUT
    at ConnectionManager.connect (/data/Jasper/SERVER_BTN95/node_modules/sequelize/lib/dialects/mysql/connection-manager.js:102:17)
    at process._tickCallback (internal/process/next_tick.js:68:7)
  name: 'SequelizeConnectionError',
  parent:
   { Error: connect ETIMEDOUT
       at Connection._handleTimeoutError (/data/Jasper/SERVER_BTN95/node_modules/mysql2/lib/connection.js:189:17)
       at ontimeout (timers.js:436:11)
       at tryOnTimeout (timers.js:300:5)
       at listOnTimeout (timers.js:263:5)
       at Timer.processTimers (timers.js:223:10)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true },
  original:
   { Error: connect ETIMEDOUT
       at Connection._handleTimeoutError (/data/Jasper/SERVER_BTN95/node_modules/mysql2/lib/connection.js:189:17)
       at ontimeout (timers.js:436:11)
       at tryOnTimeout (timers.js:300:5)
       at listOnTimeout (timers.js:263:5)
       at Timer.processTimers (timers.js:223:10)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true } }
(node:3270005) UnhandledPromiseRejectionWarning: Error: SequelizeConnectionError: connect ETIMEDOUT
    at Server.<anonymous> (/data/Jasper/SERVER_BTN95/models/server.js:58:23)
    at Generator.throw (<anonymous>)
    at rejected (/data/Jasper/SERVER_BTN95/models/server.js:6:65)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:3270005) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:3270005) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

数据库连接代码 #

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const sequelize_1 = require("sequelize");


const db = new sequelize_1.Sequelize('cw', 'root', 'mypass', {
    dialect: 'mysql',
    host: '/*I put here my VPS IP but I don’t know if I have to put 10.0.0.2 or localhost*/',
    port: my_port,
        multipleStatements : true
});


db.authenticate()
        .then(() => {
            console.log('Connection has been established successfully.');
        })
        .catch((err) => {
            console.log('Unable to connect to the database:', err);
        });


process.on('unhandledRejection', function(err) {
    console.log(err);
    // sendInTheCalvary(err);
});


exports.default = db;

尝试过的无效Promise处理代码 #

const promise1 = new Promise(function(resolve, reject) {
    throw new Error('Promise 1 has tanked.');
});

const promise2 = new Promise(function(resolve, reject) {
    promise1.then();
});

(async function() {
    try {
        await promise2;
    } catch(err) {
        console.log(err);
    }
})();

排查方向 #

• MySQL绑定地址配置
  检查MySQL配置文件（通常为my.cnf或my.ini）中的bind-address项：

  • 默认可能是127.0.0.1，仅允许本地连接。若Node.js与MySQL在同一VPS，可改为0.0.0.0（允许所有IP）或内网IP10.0.0.2；若不在同一机器，必须设为0.0.0.0或VPS公网IP。
  • 修改后重启MySQL服务：sudo systemctl restart mysql

• 数据库用户权限
  默认root用户可能仅允许localhost连接，需授权允许Node.js所在IP访问：

  GRANT ALL PRIVILEGES ON cw.* TO 'root'@'你的Node.js所在IP' IDENTIFIED BY 'mypass';
  FLUSH PRIVILEGES;
  

  同VPS环境下也可使用'root'@'%'允许所有IP，但需注意安全风险。

• VPS防火墙与安全组

  • 检查VPS防火墙（如ufw、firewalld）是否开放MySQL端口（即配置中的my_port）：
    • ufw：sudo ufw allow 你的端口号/tcp
    • firewalld：sudo firewall-cmd --add-port=你的端口号/tcp --permanent && sudo firewall-cmd --reload
  • 若Node.js与MySQL不在同一VPS，需同时开放VPS安全组（如阿里云、AWS安全组）的对应端口。

• 连接地址正确性

  • 若Node.js与MySQL在同一VPS，直接使用localhost或127.0.0.1即可，无需公网IP，避免绕路或被防火墙拦截。
  • 若为跨机器连接，确认MySQL服务的公网IP可正常访问，且端口开放。

• Promise错误处理优化
  你添加的Promise代码与数据库连接无关，无需保留。日志中的未处理Promise来自/data/Jasper/SERVER_BTN95/models/server.js:58:23处的Server类代码，需找到对应async函数，添加try/catch或.catch()处理。

内容的提问来源于stack exchange，提问作者Jerandy Landín Llópiz