javascript - Node.js 应用程序中的 SequelizeConnectionError

Question

我遇到了奇怪的问题，不知道问题出在哪里。我将不胜感激任何帮助。

我有 Node.js 应用程序，它在本地 Windows 10 计算机上运行良好。我在 CentOS 服务器中的 Docker 中成功运行了这个应用程序。该应用程序适用于远程 MySQL 和 PostgreSQL 数据库。它工作正常几天，但昨天我注意到我有错误。应用程序无法再连接到远程 MySQL 数据库。同时，如果我在本地计算机上运行应用程序或通过 DBeaver/dbForge 工具连接，我可以毫无问题地连接到远程 MySQL 数据库。

MySQL.js:

const Sequelize = require('sequelize');

const sequelize = new Sequelize('database_name', 'username', 'password', {
    host: 'host',
    dialect: 'mysql'
});

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

module.exports = sequelize;

routes.js:

const express = require('express');

const router = express.Router();

const sequelize = require('../configurations/MySQL');
const Sequelize = require('sequelize');

const passport = require('passport');
require('../configurations/password')(passport);

router.post('/search_by_name', passport.authenticate('jwt', {session: false}, null), function(req, res) {
    const token = getToken(req.headers);
    if (token) {
        sequelize.query("LONG SQL QUERY", {
            replacements: {
                name: req.body.name,
            },
            type: Sequelize.QueryTypes.SELECT
        }).then((locations) => {
            res.status(200).send(locations)
        }).catch((error) => {
            res.status(400).send(error);
        });
    } else {
        return res.status(401).send({
            status: false,
            description: "Unauthorized"
        });
    }
});

如你所见，我使用 sequelize用于将应用程序连接到远程 MySQL 数据库的库。我用来连接远程 PostgreSQL 数据库的同一个库。正如我之前所说，仅当我尝试连接到 Docker 中的远程 MySQL 数据库时，才会发生错误。 Docker中的PostgreSQL连接没有错误。是否有可能是 Docker/网络内部出现问题？

依赖关系:

"sequelize": "^4.42.0"
"mysql2": "^1.6.4"

我还认为问题的原因可能是因为很多池/连接和 Sequelize 库不会自动关闭它们。这就是为什么我多次重新启动 docker сcontainer 希望证实这个理论。不幸的是，错误并没有消失。

你觉得怎么样，会发生什么？

错误:

Unable to connect to the database: { SequelizeConnectionError: connect ETIMEDOUT
    at Utils.Promise.tap.then.catch.err (/node_modules/sequelize/lib/dialects/mysql/connection-manager.js:149:19)
    at tryCatcher (/node_modules/bluebird/js/release/util.js:16:23)
    at Promise._settlePromiseFromHandler (/node_modules/bluebird/js/release/promise.js:512:31)
    at Promise._settlePromise (/node_modules/bluebird/js/release/promise.js:569:18)
    at Promise._settlePromise0 (/node_modules/bluebird/js/release/promise.js:614:10)
    at Promise._settlePromises (/node_modules/bluebird/js/release/promise.js:690:18)
    at _drainQueueStep (/node_modules/bluebird/js/release/async.js:138:12)
    at _drainQueue (/node_modules/bluebird/js/release/async.js:131:9)
    at Async._drainQueues (/node_modules/bluebird/js/release/async.js:147:5)
    at Immediate.Async.drainQueues [as _onImmediate] (/node_modules/bluebird/js/release/async.js:17:14)
    at processImmediate (timers.js:632:19)
  name: 'SequelizeConnectionError',
  parent:
   { Error: connect ETIMEDOUT
       at Connection._handleTimeoutError (/node_modules/mysql2/lib/connection.js:173:17)
       at listOnTimeout (timers.js:324:15)
       at processTimers (timers.js:268:5)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true },
  original:
   { Error: connect ETIMEDOUT
       at Connection._handleTimeoutError (/node_modules/mysql2/lib/connection.js:173:17)
       at listOnTimeout (timers.js:324:15)
       at processTimers (timers.js:268:5)
     errorno: 'ETIMEDOUT',
     code: 'ETIMEDOUT',
     syscall: 'connect',
     fatal: true }}

Answer 1

尝试在新 Sequelize 时添加池选项。引用document

Sequelize will setup a connection pool on initialization so you should ideally only ever create one instance per database if you're connecting to the DB from a single process. If you're connecting to the DB from multiple processes, you'll have to create one instance per process, but each instance should have a maximum connection pool size of "max connection pool size divided by number of instances". So, if you wanted a max connection pool size of 90 and you had 3 worker processes, each process's instance should have a max connection pool size of 30.

const Sequelize = require('sequelize');

const sequelize = new Sequelize('database_name', 'username', 'password', {
    host: 'host',
    dialect: 'mysql',
    pool: {
      max: 15,
      min: 5,
      idle: 20000,
      evict: 15000,
      acquire: 30000
    },
});

module.exports = sequelize;

此外，您可以在 here 查看更多选项

options.pool sequelize connection pool configuration

options.pool.max default: 5 Maximum number of connection in pool

options.pool.min default: 0 Minimum number of connection in pool

options.pool.idle default: 10000 The maximum time, in milliseconds, that a connection can be idle before being released. Use with combination of evict for proper working, for more details read https://github.com/coopernurse/node-pool/issues/178#issuecomment-327110870

options.pool.acquire default: 10000 The maximum time, in milliseconds, that pool will try to get connection before throwing error

options.pool.evict default: 10000 The time interval, in milliseconds, for evicting stale connections. Set it to 0 to disable this feature.

options.pool.handleDisconnects default: true Controls if pool should handle connection disconnect automatically without throwing errors

options.pool.validate A function that validates a connection. Called with client. The default function checks that client is an object, and that its state is not disconnected