We've observed a growing number of RHEL8 users experiencing "out of memory" issues from "php-fpm"
These issues have become more prevalent as the user base increases.

A potential solution is to include the 'pm.max_requests' parameter in the package's default settings (zabbix.conf).
'pm.max_requests' provides an avenue for re-spawning a thread or child and clearing the memory that has been used, thereby addressing these memory issues.

Without this setting, php-fpm's dynamic process manager, which is responsible for handling PHP's FastCGI processes, doesn't effectively de-allocate used memory.
This can lead to unexpected memory allocation behaviors and cause the system to use swap space excessively, as demonstrated by the increased swap usage by php-fpm pool 'zabbix' processes below:

php-fpm: pool zabbix

/proc/1165/status:VmSwap:         145956 kB
/proc/1162/status:VmSwap:         137972 kB
/proc/1161/status:VmSwap:         129540 kB
/proc/1167/status:VmSwap:         127688 kB
/proc/1166/status:VmSwap:         127660 kB

→ 'pm.max_requests' into the default configuration could help alleviate the "out of memory" problem