IIS / PHP 4 Problem

Hey guys,

I am having a problem with my IIS server. It's a Windows 2000 server, so I'm using IIS version 5.0. I have PHP Version 4.3.2 installed and MySQL 4.0.15.

The main site on my server receives a huge amount of hits per week (in the millions) but every now and then (about 2 - 3 days) the site stops serving files. I have a bunch of other sites on the server and they continue to work fine. I have been told that it's most likely a PHP problem but other sites that work with PHP continue to function fine when the main site stops serving files. I'm going to put up a static HTML page next time it crashes to see if that will be served.

The only way to resolve the issue is by restarting IIS. Taking a look in the Task Manager before the reset I noticed that PHP.exe was running eleven times (and actually continues to do so now). Is that normal behaviour considering that the server will be serving PHP files pretty much continually? I would have expected to see one PHP.exe using up a lot of resources.

What is really throwing me is the fact that this only happens with one site. Are there any IIS logs I can look at that would shed any light on what is actually happening? There's nothing much in the Event Manager, I get the following Warning: "The server was unable to read the file C:\WINNT\help\iisHelp\common\404b.htm. The file does not exist.", but I can't imagine this causing one site on IIS to crash.

Anyone got any ideas at all?

You can put the questionable website in "isolation" mode, so at least the rest of IIS will keep going while you're troubleshooting. I'm not very familiar with this part of IIS though, take a look at the online help for details.

Also review the way you installed php, did you install as cgi or isapi? I've only used php as an isapi with IIS, and never at any high volume of traffic, but I haven't seen anything like what you describe. Your problem sounds like some kind of memory or resource leak. You can use PerfMon to identify these kind of problems too, but I'm not up on all the different counters available.

Thanks Doug.

I actually already have the site running is Isolation so that's probably why it only affects one site. I'll take a look at PerfMon and see if it can shed any light on the matter!

Thanks again.

Edit: Just started up PerfMon and I have counters for each process monitoring Private Bytes, but to be honest, I don't really know what I am looking at. All 7 of the processes are staying between 48 and 52 on the performance monitor. Any idea what I should be looking out for or how I would actually identify a performance or resource leak?

I'm having the same problem you described and wondered if you found a solution?

Many Thanks
Gordon

The problem in the end was that the c:\ partition was set too small, combined with not enough RAM in the machine caused the c:\ drive to become full due to the ever expanding page file. Rebooting the machine cleared the page file, which explains why it would work fine again after a reboot.

We have since moved to better, a load-balanced servers.