apache redis guidline

https://blog.gxxsite.com/laravel-redis-cache-clear-session-queue/

https://matomo.org/faq/how-to/faq_20521/


https://github.com/MISP/misp-book/issues/36

https://www.cloudways.com/blog/redis-for-queuing-in-laravel-5/


https://www.objectrocket.com/blog/how-to/top-5-redis-use-cases/


# apache mpm_prefork
https://serverfault.com/questions/269674/why-is-apache-running-so-many-processes-excessive-ram-here

https://stackoverflow.com/questions/15922194/problems-with-apache-servers-and-a-lot-of-httpd-processes

https://serverfault.com/questions/823121/why-is-apache-spawning-so-many-processes

https://serverfault.com/questions/365205/why-are-there-many-httpd-process-on-the-machine-while-i-only-started-one-apache

https://stackoverflow.com/questions/36924952/ah00161-server-reached-maxrequestworkers-setting-consider-raising-the-maxreque

https://serverfault.com/questions/684424/how-to-tune-apache-on-ubuntu-14-04-server