I recently deployed my website using Netlify for front-end and Heroku back-end, with JawsDB to handle my MySQL database. I’m able to make GET requests to my server and receive data from my db, and information from the database renders on the front-end as intended, so I know I’m accessing the database correctly.
However, I have a route for authentication, when I try to access it, I get a 500 error with this response:
What might be causing this, and how can I resolve it?
I ran heroku logs --tail and got this when trying to authenticate:
[2024-10-17T02:06:59.520160+00:00 app[web.1]: Error: getaddrinfo ENOTFOUND jaxxxxxxxxxwe.qexxxxxxsf.us-east-1.rds.amazonaws.com:3306
2024-10-17T02:06:59.520162+00:00 app[web.1]: at PromisePool.query (/app/server/node_modules/express-mysql-session/node_modules/mysql2/promise.js:356:22)
2024-10-17T02:06:59.520163+00:00 app[web.1]: at /app/server/node_modules/express-mysql-session/index.js:384:30
2024-10-17T02:06:59.520163+00:00 app[web.1]: at new Promise (<anonymous>)
2024-10-17T02:06:59.520163+00:00 app[web.1]: at MySQLStore.query (/app/server/node_modules/express-mysql-session/index.js:381:10)
2024-10-17T02:06:59.520164+00:00 app[web.1]: at /app/server/node_modules/express-mysql-session/index.js:232:16
2024-10-17T02:06:59.520164+00:00 app[web.1]: at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
The error message getaddrinfo ENOTFOUND suggests that your Node.js application is unable to resolve the host for the MySQL database. This issue typically occurs due to a misconfiguration in the database connection string or DNS resolution issues. Here’s a breakdown of potential causes and solutions:
Potential Causes:
Incorrect Database Host URL: The error message points to the fact that your application cannot find the DNS record for the database. Double-check the database host URL in your environment variables or configuration. If you’re using JawsDB on Heroku, ensure the URL is copied correctly from the Heroku JawsDB add-on. Look for typos or missing parts in the database hostname.
Misconfigured Environment Variables: Make sure that the correct environment variables for the database (like host, username, password, and port) are being passed to the application. Heroku provides these environment variables automatically through DATABASE_URL in the case of JawsDB. Ensure your app reads these variables correctly.
Region-Specific DNS Issues: If your MySQL database is hosted in a particular region (e.g., AWS RDS in us-east-1), there could be DNS propagation issues or network restrictions. Confirm that the MySQL instance can be accessed publicly and that there are no firewalls or region-specific access restrictions.
Heroku Dyno DNS Issues: Occasionally, Heroku dynos can encounter temporary DNS resolution issues. This could be a transient issue that resolves itself. However, if the issue persists, it might point to a deeper misconfiguration.
Steps to Resolve the Issue:
Verify Database Credentials:
In your Heroku dashboard, under the “Settings” tab for your app, click on “Reveal Config Vars.” Ensure that the JAWSDB_URL or equivalent database URL is correct.
If you’re manually setting up the connection string, ensure it follows this format:
mysql://username:password@hostname:port/database
Replace username, password, hostname, port, and database with the correct values provided by JawsDB.
2. Ensure Public Accessibility of MySQL: If your MySQL database is hosted on AWS RDS or a similar service, make sure it is accessible to external connections. You can check the security groups and inbound rules for the RDS instance to ensure port 3306 is open for your Heroku IP range.
3. Use the Correct Port: Make sure that the port for MySQL is set to 3306, which is the default port for MySQL unless it has been modified.
4. Test Connection Locally: You can try connecting to the MySQL database from your local machine or a MySQL client to verify that the database is reachable with the current credentials. If this fails, then the issue may be with the database configuration, not Heroku.
5. Restart Your Heroku Dynos: Sometimes, restarting the dynos on Heroku can resolve temporary issues related to DNS resolution. You can restart your dynos using:
heroku restart
Update Node.js Dependencies: Ensure your Node.js MySQL-related dependencies (mysql2, express-mysql-session, etc.) are up to date, as sometimes older versions can have bugs related to connections.
Next Steps:
Double-check your environment variables, especially the host name.
Verify if your JawsDB instance is publicly accessible.
Restart your Heroku app or redeploy the app to ensure a clean connection attempt.
By following these steps, you should be able to resolve the getaddrinfo ENOTFOUND issue and successfully connect to your MySQL database for authentication.