migrating from phpsuexec to module

Hi guys,

My server is really loaded when running phpsuexec so we will try to switch to mod_php.
For the guys who are wondering what the server is: Xeon 3G, 2G Memory. And it has only 150 accounts on it. However there are 3 accounts which are killing the machine. In the loaded hours the load average goes ot 5-6 and sometimes 8-9. This is not acceptable for me because we intend to have 500 accounts on this machine. I cant even imagine what the load will be with 500 accounts.

Ok I started talking too much . The real question is: Can someone tell me what problems could occur during the switch and what should I be careful about in order to have painless switching for me and the clients?

 

Guys. The problems are not the scripts itself. They are not the problem. The problem is the number of hits they get. The stupid CGI architecture simply can not handle high loads. I will give you a simple example
I have made some tests using my laptop as server (p3 1G with 384MB memory). The results are
when using phpsuexec i get at most 30 hits/sec
when i use mod_php i get 1500 hits/sec. Huge difference.

the php filre requested is just a simple echo "something"

Huge part of my CPU time goes as system time which is probabably the overhead coming from creating processes My load average for 24 hour period is increasing and increasing when we add new and new accounts.

One of the accounts which is generating a load is just a simple forum running IPB 2.0. Nothing unusual. But it has lots of accesses some times and this kills the machine. However the traffic generated is not that much ~ 10G/month

I am running CentOS 4.2 with custom kernel 2.6.14.6-grsec. In the loaded hours the system time is about 40-50%. I think this is way too much. I dont want to migrate to module too, but no choice so far.

If someone has and Idea how I can decrease the load I would be really happy. I have seen hosting server with 700 account which load during high loads is around 2-3 I really dont understand how they do this.

 

Regarding GRSEC stuff:
I have not booted grsec disabled kernel on this machine but i tried in the office what is the difference in speed between grsec and non grsec kernel. I found no difference. The test was 10000 times to start /usr/bin/php p.php > /dev/null
p.php is just echo "something"
And measure the time taken to do this. No difference.
I will really feel bad if I run with no grsec kernel

1. MySQL. I havent done any optimization but mysql is not consuming any cpu. For uptime 12 days all mysql intances have used ~ 10 min. time. I dont think this is the problem. When I say to top to sort by CPU usage, Mysql does not even shows
2. Disks: I use sata disks, The IO/WAIT time is 0% almost all the time. This could not be the issue
3. SWAP file usage: 0%
4. MaxRequestsPerChild: just set it to 100. Will wait for the results
5. Zend optimizer slows the things down if I am not wrong. This is just another one .so to load and according to my simple echo "something" tests, when i load zend the hits per second goes down. Probably this is wrong measurement but I could give it a try on the server if you say I should .

 

High load is coming from creating php instances. No specific process is on the top. The are changing really fast and no specific process on the top of cpu usage.
MaxRequestsPerChild - just fixed it.

I think the load is comming from the number of hits i get. They are not coming from spceific ip but from different ones and seems like legal requests. In the time i am writing this i have 130 connections to the server (including time_wait) ones. And load average is 1.82 which is not loaded time.
Every morning until 10 AM everything is fine. And load is 0.6 - 0.8 and in the aftenoon start the load

 

you will get the info. I will post it once the load starts which will be in around 3 hours from now

 

As soon as grsec releases patch for later kernel

 

I just found what the problem is

Hi guys. I just found why the server was so fuckin slow. It is good to share this with other people which face the same problem.
The problem was the mm library compiled in php. After 3 weeks of testing and recompiling php i noticed that cpanel installation is much slower than mine installs. After another day of recompiling php i managed to find that when i compile mm library in php the speed decreases by 8 times yes you read correct it is EIGHT times slower when you compile mm. When I removed it from my server the load dropped from ~3 to 0.5-1 which is realy great improvement . Thanks for the help.

 

You could have told me this yesterday, couldnt you ?

With the performance i have now, phpsuexec is just great. I didnt even imagine that something that stupid which actually is used for speeding up php can kill the machine. On machine P3 733 Mhz it takes 200 ms to start php and exit and the script just do echo "something". This is insane time man . I told this to cpanel support and I hope they will be able to help to other users with simalr problem, because they advised me to migrate to module and I really didnt wanted to