Re: [PHP4BETA] Zombie Proccesses at 250+ reqs/min. High load php...

You've left out lots of information that would help us help you.
What kind of platform are you using?  Is your machine designed to handle 
that amount of traffic, even without PHP?

- For instance, if you're using Linux, you may be bumping into some kernel 
compile-time-defined limits.  I guess other operating systems would have 
equivalent configuration issues.

- How do you know that the PHP processes are zombies?  Did you try 
attaching to one of the stuck processes with a debugger, or even with 
strace (or equivalent)?

As for your questions.  Generally, objects are slower than most other 
things in PHP.  There should be no problems redirecting.  Opening and 
closing files at high speed is not an issue, assuming you're not locking 
(using flock()).  Some operating systems (like most versions of Linux) 
don't work very well at high load with flock().  You don't have to release 
any resources in PHP in general, and in CGI in particular.  When the script 
terminates, the process dies, and everything it acquired is destroyed at 
the operating system level.  Even if it weren't so - PHP automatically 
frees everything by itself upon shutdown.

Zeev

At 12:30 08/06/2000, August Zajonc wrote:
>Hey folks,
>
>A site I run has begun hitting over 250 reqs/minute which is great :) What's
>not so great is that the PHP stuff I put together can't seem to handle the
>load. I'm looking for others sense of what may be going on. It is exciting
>to run a high traffic site using PHP, but we can't do so if PHP falls down.
>
>I'm most interested in ways in which PHP might create zombies and/or exit
>uncleanly. In a high load situation this can be deadly.
>
>Running PHP4.0.0 as a CGI, using something similar to the optimized version
>of php.ini.
>Sessions are enabled and used. Auto Start == true
>The general outline of a page load is a call to a script which includes()
>3-4 files,
>creates a new instance of a larger class (2,000 lines or so),
>calls the appropriate methods on the class,
>exit those methods, opens a logfile and writes some auditing data.
>
>
>A couple of questions include:
>What's the overhead on creating a large class? We can certainly avoid doing
>so.
>Often times the script sends out a redirect. Any chance this blows things
>out of the water?
>Would opening and closing a log file at that rate lead to problems?
>Anyone else have high load problems with PHP4? We might be able to backport
>and do our own sessions.
>Do we need to make sure we call exit? Release resources?
>The script tends to execute in something like .3 seconds and is not
>long-running from that point of view.
>
>We are already planning on moving to mod_php.
>What concerns me is the specter that PHP is leaking resources or generating
>zombies which will not disappear no matter how much hardware we throw at the
>problem. Tips and tricks for very high load programming (going onto a
>million requests/day) would be appreciated. Gotchas especially within the
>language. We've got a ton of global statements, does that matter? You
>wouldn't think so but who knows? We are certainly going to throw hardware at
>the problem.
>
>Basically, I'd love to have PHP scale along for the ride! It's a great
>package.
>
>August Zajonc
>Please CC me if possible as my free access net connectivity is limited and
>it is hard to track the list directly :)
>
>
>
>
>
>
>
>
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