Website frequently reaches the max_children PHP-FPM limit

Question

The domain is constantly reaching the max_children PHP-FPM limit. What can be done to alleviate this?

Answer

If your domain constantly hits the max_children limit, even after you raise the value, you first should check to see if the server is experiencing a DoS attack:

How can I tell if Apache is experiencing a DDoS attack?

If you confirm that the traffic is legitimate and is not due to a DoS attack, you may consider a few options:

• Consider switching to the LSAPI handler, which does not have a max_children limits and provides similar performance:

  How to switch from PHP-FPM to the LSAPI handler

• Migrate the site to a different server with more resources.
• Upgrade the resources of the existing server.
• Consult with a systems administrator to optimize the site to use fewer resources.

Additional Resources

How to check if a website is reaching max_children in PHP-FPM

How to modify the max_children limit for PHP-FPM