[Mediawiki-l] Debugging MediaWiki crash in PHP + MediaWiki Error on Windows

[Monahon, Peter B.]

> RE: Debugging MediaWiki crash in PHP
> Earlier: "...[how] to determine 
> the cause of a MediaWiki crash
> "PHP has encountered an Access 
> Violation at 77FCC2C0"

Peter Blaise responds:

I just did some reading at Google:

http://www.google.com/search?hl=en&q=PHP+has+encountered+an+Access+Viola
tion+at+77FCC2C0&btnG=Google+Search

http://www.google.com/search?hl=en&q=77FCC2C0&btnG=Google+Search

Sounds like an illegal instruction trying to do something in a memory
address that can't be done - perhaps a corrupt executable or dll dynamic
link library.

You can try rebooting clean and unloading any non-needed programs (even
ant virus) and see if the problem goes away.

Also, reboot in safe mode and clean out all cache and temp files, and
scandisk the drive, reboot, and try again.

You may have to replace corrupt programming wherever it is - hard to
find.  Operating system?  Drivers?  Utilities?  Web server?  PHP?
Extensions?

There are many memory scanners (including debug) that may allow you to
browse and identify what's sometimes (emphasis on "sometimes") located
at 77FCC2C0, but I suspect that what's there changes whimsically, and
it's a meaningless error message - most are.

You could also have a real bad memory chip that you can swap or remove,
or messed up CMOS, which you can update.  I'd r&r remove and reinstall
all computer parts, clean connections, leave the cabinet open and add
big fan to keep it cool to test.  Everything in the computer may be
capable, but perhaps the power supply is under-powering the memory
chips, or other accessory is draining too much power - remove unused
accessories (modem, sound card).

Threshold problems like this are not processional to troubleshoot.  I've
had to work on everything, one step at a time, and sometimes moving to
an entirely new computer turns out easier.  

Is it time to migrate to a new computer, rebuild the current server, and
implement it as a backup anyway?  Take advantage of the crash to buy
new.

Let us know.

--

> Re: MediaWiki Error on Windows
> Earlier: :...[help with] nasty 
> systems log error...in Windows:

9/24/2007	12:40:07 PM	WAM	Error	None	204	N/A
WWW-STL-52	The HTTP server encountered an unhandled exception while
processing the ISAPI Application '
wam!WAM_REQ_CORE::GetSz(unsigned long)const  + 0x51
php5isapi + 0x1172
wam!DllCanUnloadNow + 0x636
wam!DllCanUnloadNow + 0x20C
w3svc!HTTP_HEADERS::FindValue(char const *,unsigned long *) + 0xE2
w3svc!STR::Copy(char const *,unsigned long) + 0xC71
w3svc!STR::Copy(char const *,unsigned long) + 0xB49
w3svc!STR::Copy(char const *,unsigned long) + 0x9A2
w3svc!CLIENT_CONN::OnSessionStartup(int *,void *,unsigned long,int) +
0x642
w3svc!HTTP_HEADERS::Reset(void) + 0x1CA
w3svc!IIS_SERVER_INSTANCE::LockThisForWrite(void) + 0x63C
w3svc!IIS_SERVER_INSTANCE::LockThisForWrite(void) + 0x5AF
ISATQ!_AtqWriteSocket at 16 + 0x218
ISATQ!CDirMonitor::RemoveEntry(class CDirMonitorEntry *) + 0x13A
 + 0x7B0EEF7A

Peter Blaise responds: 

I just did some MORE reading at Google:

http://www.google.com/search?hl=en&q=HTTP+server+encountered+an+unhandle
d+exception+while+processing+the+ISAPI+Application&btnG=Google+Search

http://www.google.com/search?hl=en&q=wam%21DllCanUnloadNow&btnG=Google+S
earch

http://www.google.com/search?hl=en&q=w3svc%21STR%3A%3A&btnG=Google+Searc
h

... and so on.  You could read, read, read everyone else's reports on
seeing similar error message lines, but I do not think you'll find a
quick and simple answer like, "Put the balls on the other side."!

What system log?  Who's error report?  This feels the same as above [RE:
Debugging MediaWiki crash in PHP] above.  You may be in for a serious
reinstall ... AFTER carefully and thoroughly confirming that every piece
and part in the system is perfect, not intermittent, and not part of a
cascade failure (like an overheating video chip overloading the power
supply and causing the hard drive to miswrite data - I'm on my 4th
computer and now have a 9 inch fan flowing on it!).  

The first think I do is remove the hard driven, copy it to a spare, and
then work from there.  Really, though, installing fresh on another
machine and migrating may be worth consideration.  25 wikis, eh?  What's
the plan for bringing them back up after the server fries?  Now's the
time to develop one and implement it!

Let us know how it goes.