Apache :: Debugging access violation in Windows for Apache

neelyae · Joined: 03 Oct 2012 Posts: 3

Hi all,

I am getting the error "[notice] Parent: child process exited with status 3221225477 -- Restarting." in my Apache error logs. With a little bit of research, i found that this error is an access violation with apache. The question is, what is it trying to access?

I am trying to use dr. watson as a debugger on my Windows 2k3 machine to debug the apache child process to see what apache is trying to access during its crash. I followed the instructions on the httpd.apache.org site (http://httpd.apache.org/dev/debugging.html#backtrace-win) on how to generate a backtrace but unfortunately, i dont believe i am doing it correctly. In my dump file generated after some sort of crash, i see "FAULT ->ntdll!DbgBreakPoint:
00000000`77ef2360 cc int 3" which from google searches seems to be a hardcoded break point with dr. watson. This isnt what i was looking for.

I found an article with a gentlemen debugging an application using dr. watson and he too got this error. He found that using dr. watson to debug an application in windows can cause this hard coded error as dr. watson forces the application to use its memory heap instead of the one the application uses. When memory is allocated or moved, it can cause this break. Seems like a false positive.

In this same artcile, he makes reference to using gflags instead as it uses a better heap and avoids the issue above. I could not find any information on gflags and using it to debug apache.

My overall question is, is there any clear information on how to debug apache in windows and what to look for when viewing the dump? So far, i havent gotten much of anywhere.

Steffen

Search this forum with keyword 3221225477 with http://www.apachelounge.com/search.php

You get a lot of hits.
Mostly the cause is PHP when you run it as module, running with FastCGI solves it.

Debugging can be done when you build Apache yourself and use the debugger in Visual Studio.

Steffen

neelyae · Joined: 03 Oct 2012 Posts: 3

Hi steffen,

Thanks for the reply! Instead of migrating my environment from php loaded as a module to using mod_fcgi, i am hoping i can just find this issue. It only started a day or so ago and i believe its something being referenced in code, i just cant narrow down what it is. If i have to, i will migrate to fcgi but i would like to hold off on that unless its absolutely necessary. There are alot of new params to learn with fcgi.

Debuggings using dr. watson, gflags, GDB in windows, UMHC, etc seems to be a decently common practice, i just cant seem to find thorough documentation on it.

admin · Site Admin Joined: 15 Oct 2005 Posts: 692

Have no experience with Watson etc. use only VC for debugging.

The 3221225477 issue is PHP it self mostly. It is common to use FastCGI with PHP,at least for the webmasters here. Stability.

neelyae · Joined: 03 Oct 2012 Posts: 3

Yeah i wasnt too thrilled with dr. watson. I am not opposed to using a different debugger, VC could work fine, i just cant find any information on doing the debugging with it.

I honestly would like to migrate to a fcgi environment due to the multiple processes vs the single child process but again, there is a ton of new params to sort through and i currently do not have a good way of load testing other than trying it live. The last time i had this particular error, it was from using jpgraphs. What i am hoping to find in the debugger is what file the bad code is in or what is being referenced to cause the access violation error.