Nginx - php fpm max children error

Hello.

php fpm max children (server reached pm.max_children setting (5), consider raising it)

The value of "pm.max_children" in php-fpm seems to be small, so please try increasing the value.
I think it's a good idea to calculate this value based on the instance's memory size and the average memory usage of php-fpm.
https://www.php.net/manual/en/install.fpm.configuration.php

I often use the calculation method below.

pm.max_children = available memory of instance / average memory usage of php-fpm process

(111: Connection refused) while connecting to upstream, client: 172.31.16.34, server: , request: "GET / HTTP/1.1", upstream: "fastcgi://172.17.0.4:8000",

You are trying to connect to "fastcgi://172.17.0.4:8000", but please check if this IP address is correct and if this IP address is listening on port 8000.