How to solve 502 error on nginx - digitalocen while generating pdf file?

I have problem with generating pdf files on digital ocean nginx server. I have MERN app and I use “html-pdf-node” library to create pdf files. It works on localhost but error is on digital ocean nginx server. Every time i try generate pdf i have the same error:

502 Bad Gateway
nginx/1.18.0 (Ubuntu)

It is my log error:

upstream prematurely closed connection while reading response header from upstream, client

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Site Moderator
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October 12, 2022

Hello there,

You can verify that Nginx is running fine. 502 Bad Gateway Nginx is a generic Nginx error.

To check the status:

  1. sudo systemctl status nginx

If there is an error message you can also check the journal logs to extract additional information:

  1. journalctl -xe

To restart the service:

  1. sudo systemctl restart nginx

I would recommend checking your error logs:

  1. tail -f /var/log/nginx/error.log
  2. Also, I'll include this question from our community, make sure to check Bobby's reply as it includes really useful information (video of troubleshooting as well)
  4. Regards
Site Moderator
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October 12, 2022

Hi @happygreenbluejellyfish,

Are you using Nginx as a proxy? If yes, try setting higher values for the proxy like so:

    proxy_read_timeout 300s;
    proxy_connect_timeout 75s;
    proxy_pass http://localhost:9000;

If you are not using a proxy and the error you see in Nginx is the only thing you see in there, I’ll recommend checking out your Application and the error logs on it.

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