Long script blocks other requests in PHP-FPM / Nginx

Hi all,

I’m facing an issue I don’t manage to resolve. I have a PHP application which executes FFMPEG to convert videos. This script is quite long to execute because of FFMPEG conversion time. The problem is, while this script is executing, all other requests sent to Nginx / PHP-FPM are waiting and don’t execute, and I can’t find the proper configuration to make this work.

In nginx.conf, I have this:

worker_processes 2;
worker_connections 768;
multi_accept on;
keepalive_timeout 65;

In PHP-FPM www.conf:

pm.max_children = 10

The application is developed with Symfony2.8 and you’ll find below the typical error message I get, which is a MySQL timeout but digging a bit on the internet, I narrowed the problem to a server configuration issue:

SQLSTATE[HY000]: General error: 1205 Lock wait timeout exceeded; try restarting transaction

Does any of you have any idea what could prevent requests to be executed when a PHP script is already running?

Thanks for your help, Best regards, Romain

Show comments

Submit an answer

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

Sign In or Sign Up to Answer

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Want to learn more? Join the DigitalOcean Community!

Join our DigitalOcean community of over a million developers for free! Get help and share knowledge in Q&A, subscribe to topics of interest, and get courses and tools that will help you grow as a developer and scale your project or business.

This question was answered by @strime:

Ok, eventually ended up finding the solution. The problem is not related to Nginx / PHP-FPM blocking requests while a long running script is executed. It is due to the fact that the server only accepts a maximum number of simultaneous connections coming from the same browser. If you have ajax requests in your pages, it increases this number of connection. Trying to open the website in multiple tabs is then blocked. I’ve not found a solution yet to solve this problem, but at least I know that the other visitors are not impacted.

View the original comment