Reduce memory consumption of apache/php processes

Help! (Home for newbies)
1

I use virtualmin to manage my web server. For performance reasons, the database server is hosted on another VPS. Therefore, the server hosting virtualmin has only two active services: SSH and APACHE

I have noticed that, as the hours go by, there is a very high memory consumption for processes linked to apache / php (print attachment).

memory-example
memory-example853Ă—453 41.1 KB

this consumption is so strange, that webmin refuses my connection to the manager (URL.COM:10000).

normally, to reduce this high memory consumption of the processes involving apache, I have to access the server via SSH and restart the apache services.

Thus, the memory goes back to 400mb/500mb. however, after a few hours, the processes again consume a large amount of memory.

I already looked for some topics here in the forum, but I did not find any information that would help me to reduce this high memory consumption of processes involving apache/php.

I don’t know if I should limit the time (age) of these processes (I don’t even know if there is a way to do this).

for information:

  • there are 8 virtual servers configured in this VPS
  • PHP’s memory limit is 256mb for 2 sites. the others I put 128mb
  • there is no high access traffic to justify this high consumption

Has anyone had this problem? is there a solution?

tks

2

tweak php/apache, move to php-fpm, setup firewall in case this is an web attack of some sort…
logs should help investigate what is causing the high mem/swap usage.

3

hi @dimitrist,

I believe that a web attack can be mitigated because there is cloudflare managing the DNS (and promoting the necessary solutions).

I will test changing the script execution mode to php-fpm, however, I have a question: is not php-fpm less secure?

tks

4

properly setup php-fpm can be more secure than the apache module/cgi. security doesn’t depend on just one thing, rather on the whole web setup…

about cloudflare, i don’t trust/use it. and for low volume websites it seems unnecessary, could be slowing them down.

5

this has nothing to do with attacks on a new system. its directly related to your php configuration for virtual servers.

for example, take a look at the following php-fpm configuration on my system…notice that i have set “pm=ondemand”. This reduces your memory load for that Virtual Server dramatically

virtualmin php fpm configuration
virtualmin php fpm configuration1364Ă—671 81.5 KB

also, check in webmin > Servers > Apache Webserver > Modules and make sure that “mpm_prefork” is not the one selected.

webmin mpm module
webmin mpm module1918Ă—984 176 KB

this uses huge amounts of memory on the server and is the apache default (nothing to do with Virtualmin). In all honestly, the mpm_prefork setting is absolutely hopeless for me where i offer shared webhosting services for clients. I always change it to either mpm_event or mpm_worker.

Both of the above can also be configured as a default option for your system.

I have altered my php configuration files for all new virtual servers so that “pm-ondemand” doesnt need to be done manually every time you create a new virtual server. The default configuration file has “pm=ondemand” as the default already.

doing the above 2 things will save an enormous amount of system memory…especially as you add more virtual servers to your system.

3 Likes
6

thanks.

I’ll make some changes and let you know if it works out.