Zend certified PHP/Magento developer

Magento2 display 502

Translation: Recently, my Magento 2.4 website keeps showing a 502 error. I have checked the Nginx server and it seems to be working fine. I also have error logs for PHP.

ready to handle connections
[20-Sep-2023 09:22:43] NOTICE: systemd monitor interval set to 10000ms
[20-Sep-2023 09:54:35] WARNING: [pool www] server reached pm.max_children setting (50), consider raising it、

Every time only kill the PHP process, restart PHP-FPM. However, after a while, it was hung again.How can I solve this? Have you ever encountered it?