Determining system limits affecting Apache

sean.simpson · 03-15-2011, 01:53 PM

Hi All,

Our Apache server is pretty much configured straight out of the box, and I've noticed it is using far more CPU and less memory than another server where I have the following:

RLimitCPU 8
RLimitMEM 100000000
RLimitNPROC 24

The Apache documentation says that if these aren't set, the values are obtain from the OS. How can you tell what those are? I'd like to see if I can tune Apache's performance, but I don't even know if these values are higher or lower than what it's currently using...

jcalzare · 03-15-2011, 02:06 PM

Check in /etc/security/limits.conf and ulimit -a.

sean.simpson · 03-15-2011, 02:18 PM

Quote:

Originally Posted by jcalzare

Check in /etc/security/limits.conf and uname -a.

/etc/security/limits.conf has nothing but commented out lines, and not sure how uname is supposed to help. It doesn't provide process ino... unless you are asking me what OS I'm running and wanted to see the output?

All help is appreciated!

jcalzare · 03-15-2011, 02:24 PM

Yeah I edited my post earlier, meant to type ulimit, not uname.

szboardstretcher · 03-15-2011, 02:32 PM

Quote:

Originally Posted by sean.simpson

/etc/security/limits.conf has nothing but commented out lines, and not sure how uname is supposed to help. It doesn't provide process ino... unless you are asking me what OS I'm running and wanted to see the output?

All help is appreciated!

RLimitCPU 8
RLimitMEM 100000000
RLimitNPROC 24

Code:

ulimit -a
max memory size         (kbytes, -m) unlimited
max user processes              (-u) 1024

CPU, I am unsure of.

sean.simpson · 03-15-2011, 02:35 PM

Quote:

Originally Posted by jcalzare

Yeah I edited my post earlier, meant to type ulimit, not uname.

That makes more sense, but still has problems. ulimit is a bash command, meant to show the process limits of the existing shell (the answer was unlimited, btw). Even as root, I still get unlimited. Does that mean Apache *isn't* placing any limits on memory as is? I know our php.ini file limits per process memory to 16MB, maybe I should be looking at that as the ceiling?