Slow page load with PHP-FPM 7.2

Hi guys,

i’m having troubles with PHP-FPM.

My droplet:

Dedicated 8 vCPUs 32 GB RAM Ubuntu 18.04.3 (LTS) x64

RAM usage - about 10% CPU usage - about 6%

My application has about 600 online users (on the top usage time). The avarage proccess memory is about 90mB.

My PHP-FPM pool config:

pm = dynamic pm.max_children = 300 pm.start_servers = 32 pm.min_spare_servers = 16 pm.max_spare_servers = 32 pm.process_idle_timeout = 5s pm.max_requests = 1000

process.max = 512 (php-fpm.config)

The problem:

At random times, my application stay very very slow, almost frozed. My log said:

[18-Jan-2021 17:31:26] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 16 children, there are 178 idle, and 256 total children

Then, i increase drastically (3x more) (max_children, start_servers, min/max_spare_servers and max_requests), and restartáramos php7.2-fpm service. And then, no changes happen.

So, i return to original parameters (with 20% more then initial) and no effects.

And after 40/50min of slowing, my system returns to normal velocity. And I dont know what causes this.

Does someone can help me?

Thnks since now!