ETIMEOUT error | Google Cloud SQL database with NodeJS

Question

I have created a mysql database on google cloud that I'd like to access from a separate node web application (also running on google cloud). I am testing the connection locally on my computer first, and when I run the following code locally I can successfully establish a connection to my database and see the data in it.

'use strict';

// [START app]
const express = require('express');
const bodyParser = require('body-parser');
const path = require('path');
const app = express();
const mysql      = require('mysql');

var connection = mysql.createConnection({
  host     : 'Cloud SQL IP',
  user      : 'username',
  password  : 'password',
  database  : 'db_name'
});



// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }))

// parse application/json
app.use(bodyParser.json())

// Make globals.js accessible
app.use(express.static(__dirname + '/'));


app.get('/', (req, res) => {
    connection.connect();

    connection.query('SELECT * FROM Users', function (error, results, fields) {
        if (error) throw error;
        console.log(results);
    });

    connection.end();
    res.status(200).send('Hello World!');
});

app.get('/login', (req, res) => {
    res.status(200).send();
});

// [START server]
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(`App listening on port ${PORT}`);
  console.log('Press Ctrl+C to quit.');
});
// [END app]

However when run this same code in my google app engine (for both debugging on port 8080 and fully deployed on https://myapp.appspot.com ) I get the following timeout error:

{ Error: connect ETIMEDOUT
    at Connection._handleConnectTimeout         (/home/megan_cooper2900/project/node_modules/mysql/lib/Connection.js:419:13)
at Socket.g (events.js:292:16)
at emitNone (events.js:86:13)
at Socket.emit (events.js:185:7)
at Socket._onTimeout (net.js:338:8)
at ontimeout (timers.js:386:14)
at tryOnTimeout (timers.js:250:5)
at Timer.listOnTimeout (timers.js:214:5)
--------------------
at Protocol._enqueue (/home/megan_cooper2900/project/node_modules/mysql/lib/protocol/Protocol.js:145:48)
at Protocol.handshake (/home/megan_cooper2900/project/node_modules/mysql/lib/protocol/Protocol.js:52:23)
at Connection.connect (/home/megan_cooper2900/project/node_modules/mysql/lib/Connection.js:130:18)
at app.get (/home/megan_cooper2900/journeyma/app.js:31:13)
at Layer.handle [as handle_request] (/home/megan_cooper2900/project/node_modules/express/lib/router/layer.js:95:5)
at next (/home/megan_cooper2900/project/node_modules/express/lib/router/route.js:137:13)
at Route.dispatch (/home/megan_cooper2900/project/node_modules/express/lib/router/route.js:112:3)
at Layer.handle [as handle_request] (/home/megan_cooper2900/project/node_modules/express/lib/router/layer.js:95:5)
at     /home/megan_cooper2900/project/node_modules/express/lib/router/index.js:281:22
    at Function.process_params         (/home/megan_cooper2900/project/node_modules/express/lib/router/index.js:335:12)
  errorno: 'ETIMEDOUT',
  code: 'ETIMEDOUT',
  syscall: 'connect',
  fatal: true }

Why is this not working on the Google App Engine application?

Answer 1

In your connection configuration for mysql, host does not work on App Engine. You have to use socketPath . socketPath is the path to a unix domain socket to connect to. When used host and port are ignored. (transferred knowledge from using Loopback on App Engine flex. it had me banging my head for days lol). It's value is your Cloud SQL Instance connection name

so in your case, it should look like this: /cloudsql/my-project-12345:us-central1:mydatabase

var connection = mysql.createConnection({
  socketPath     : '/cloudsql/my-project-12345:us-central1:mydatabase',
  user      : 'username',
  password  : 'password',
  database  : 'db_name'
});

It's a similar process if you're using Postgres on GCloud which is answered here

Answer 2

I also did faced the same issue and I was using Kubernetes pods to access my CloudSQL instance. I got a fix by increasing the timeout in the configuration.

cloudSqlConfig: {
    connectionLimit: 10,
    host: 'your-host-ip',
    user: process.env.DB_USERNAME,
    password: process.env.DB_PASSKEY,
    database: 'myDB',
    connectTimeout: 20000,
    waitForConnections: true,
    queueLimit: 0
},