Topic: RLimitMEM & RLimitCPU with Virtual Hosts and PHP

[mmcdermo]

Hello there!
I'm working towards an apache setup where I have several virtual hosts running a PHP application. If I set RLimitMEM and RLimitCPU for each virtual host, would this limit CPU and Memory on the processing of a PHP script run by one of the virtual hosts? I'm confused about what happens when a PHP script is executed; In the apache docs for RLimitCPU, they note

[Brian]

I did a quick google search at:

http://www.google.com/search?q=RLimitMEM+%2Bwindows&start=0

and it appears after reading a few of the results that this is not going to benefit you in a Windows Environment.

For me, when I use PHP in a SAPI execution environment I do set in the defualt PHP.INI file the basic generic one size fit's all standards for memory use, basedir (/www/), time of execution and so on. Then you can apply this to all vhosts and make adjustments in the VHOST containers as needed.

If you use CGI, it must all be contained wtihin the PHP.INI file.

But because of how Windows and Apache work (quite different from Linux, which others can surely better explain than I can), you will need to control this from the PHP settings.

Are you using CGI/FCGI or the Apache Modules (SAPI)?

[mmcdermo]

I haven't decided which to use yet, as I'm not familiar with the restrictions of each. Which would you recommend?

[Brian]

If you are running a single domain, or domains that you manage and have complete control in a PHP environment, then personally I'd most likely go with FCGI. It's fast, nearly or as fast as SAPI and its rock solid stable.

SAPI (Apache Module) is very flexible for environments that need differing PHP settings for each vhost or even directory and location. I have about 550 vhosts, and I can set up PHP for each completely different. Of course this also puts a burden on the server, and it needs a lot more ram and horsepower as you ask it to do more.

So if you can use FCGI for your needs, it is the way to go, uses far less ram, is very stable, is very fast, and is very easy to set up (for the most part). Just remember that if you use FCGI/CGI then you cannot control anything for each VHOST, Location, or Directory as you can with SAPI connector, all vhosts use the same PHP.INI settings.

[mmcdermo]

Thank you for your detailed and thorough reply! With this new information, it looks like I'll have to do more testing to determine whether limiting the resources a specific Virtual Host's PHP scripts would use is more important than having more resources to allocate.

Thanks again for your speed and the quality of information, Brian. I'm sure I'll come back to these forums if I have any more Apache-related problems .

[Brian]