502 error when running Node app with PM2

Posted March 19, 2020 7.5k views

I have followed the instructions laid out in this tutorial

I can successfully run my application using

$ sudo node app.js

and access it in my browser.

However, when I run the app using

$ pm2 start app.js

it says the app is running but when I access it in the browser I get a 502 Bad Gateway error. Any ideas?

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1 answer

Hi there @digitaloceanjd,

It sounds like that the application might not be starting, what happens if you try to get information for your application with:

  • pm2 info app_name

And also try to use the pm2 monit command to check the status of the application.

I would also recommend checking your Nginx error logs:

tail -100 /var/log/nginx/error.log

Another thing that I could suggest is making sure that your application is listening on the correct port:

sudo netstat -plant

Also, as a side note here is also a quick video on how to deploy Node.js with PM2, Nginx as a reverse proxy, and Cloudflare for SSL termination:

Let me know how it goes!

  • Hi Bobby, thanks for your response!

    running $ pm2 status says that the app is online.

    running $ tail -100 /var/log/nginx/error.log shows this error:

    (111: Connection refused) while connecting to upstream, client:, server: <example>.com, request: "GET / HTTP/1.1", upstream: "", host: "<example>.com"

    so it seems to be a permissions issue with pm2 - any ideas?


    • Hi there @digitaloceanjd,

      Thanks for sharing the extra details!

      I would recommend running a netstat to make sure that your backend application is actually listening on port 9000. To do that you can run the following command:

      netstat -plant

      Feel free to share the output here.

      Also, another thing that you could share is the exact Nginx server block that you are using.