I host a wordpress site on my server which has 2GB mem, I have used some cache plugin, but when I type ps -eo %C : %p : %z : %a | sort -k5 -nr in SSH, I see the httpd memory usage is very high.15.7 :  3131 : 4732740 : /usr/local/mysql/bin/mysqld 0.5 :  3356 : 515860 : /usr/sbin/httpd 0.6 :  3363 : 509308 : /usr/sbin/httpd 0.6 :  3333 : 509308 : /usr/sbin/httpd 0.5 :  3367 : 509308 : /usr/sbin/httpd 0.5 :  3361 : 509308 : /usr/sbin/httpd 0.5 :  3358 : 509308 : /usr/sbin/httpd 0.5 :  3338 : 509308 : /usr/sbin/httpd 0.4 :  3366 : 509308 : /usr/sbin/httpd 0.3 :  3370 : 509308 : /usr/sbin/httpd 0.3 :  3359 : 509308 : /usr/sbin/httpd 0.0 :  3193 : 410980 : /usr/sbin/httpd ...The server always dead. I have set memory in php.ini like this:memory_limit = 768Mmemory = 20M
httpd memory usage very high
memory;php;apache httpd
Main reason for your server load is due to memory_limit (768M) of php.ini. As your server has only 2GB ram could not able to handle if more http request made into the server leads of multiple connection of php that consume more memory. so, i suggest you to decrease the global php.ini memory_limit to optimal that is below 200M to control the load.