Logging PHP Access Violations

[Dabbler]

Members report seeing:
PHP has encountered an Access Violation at 7C8224B2

but nothing is being reported in the php error log.

How can I trap/record/diagnose this event?

[doug1]

Have a look here:

http://www.vbulletin.com/forum/showthread.php?t=211513

[Dabbler]

Unfortunately, that thread has nothing about trapping/logging the event in question.

Anyone with ideas on how to "trap/record/diagnose" the Access Violation event?

[Scott MacVicar]

It's a Windows error though its usually resource related.

I'll assume your running IIS to begin with and ISAPI too.

What version of PHP?

[TommyBALL]

The Access Violation message comes from the PHP ISAPI module (php5isapi.dll) that is part of the PHP package. It is most likely triggered by resourcerelated bugs in one of its subcomponents (like php extensions etc).

Although PHP itself is coded in a threadsafe manner, many of the extensions are not. Running a non-threadsafe component in the threadbased ISAPI environment is unfortunately a recepie for disaster. This is why MicroSoft and Zend are working closely together to implement a FastCGI component for IIS (a new preview of that is coming this month). CGI/FastCGI works better with the non-threadsafe coding habits used with many Linux/Unix environments.

If you want to debug the issue yourself, I have dug up a link that might put you on the track.
How to debug ISAPI DLLs

http://support.microsoft.com/kb/183480

Regards
- Tommy

[Dabbler]

It's a Windows error though its usually resource related.

I'll assume your running IIS to begin with and ISAPI too.

What version of PHP?

System profile here:

http://www.vbulletin.com/forum/showthread.php?t=213284

[Dabbler]

The Access Violation message comes from the PHP ISAPI module (php5isapi.dll) that is part of the PHP package. It is most likely triggered by resourcerelated bugs in one of its subcomponents (like php extensions etc).

Although PHP itself is coded in a threadsafe manner, many of the extensions are not. Running a non-threadsafe component in the threadbased ISAPI environment is unfortunately a recepie for disaster. This is why MicroSoft and Zend are working closely together to implement a FastCGI component for IIS (a new preview of that is coming this month). CGI/FastCGI works better with the non-threadsafe coding habits used with many Linux/Unix environments.

If you want to debug the issue yourself, I have dug up a link that might put you on the track.
How to debug ISAPI DLLs

http://support.microsoft.com/kb/183480

Regards
- Tommy

Very helpful. THANKS!

[Dabbler]

Is there a list of which DLL's should be enabled in php.ini?

I don't have them all enabled, but I do have maybe a dozen which have been turned on over the years. I'm thinking it would be useful to review this list as some of them probably date back to when we were using PHP 4. (not sure about that, tho')

Using:
CPU: dual 3.2 GHz Intel Xeons
RAM: 4GB
HD: 73GB SCSI x2 (RAID 1)

OS: Windows Server 2k3
Web: IIS 6.0 (isapi mode)
W3WP: 4 processes recycled every 4 hours or every 10,000 requests

PHP: 5.2.0 (from php.net, not from Zend)
MySQL: 5.0.26 nt-community
vB: 3.6.0

[TommyBALL]

Here are the extensions I use on my vBulletin dedicated server (specs in my sig)

extension=php_xcache.dll
extension=php_gd2.dll
extension=php_mbstring.dll
extension=php_mysql.dll
extension=php_mysqli.dll

Regards
- Tommy

[Dabbler]

Are you using FastCGI or ISAPI?

xcache is for a PHP accelerator?

And where do you use mysqli?

[TommyBALL]

Are you using FastCGI or ISAPI?

ISAPI

xcache is for a PHP accelerator?

Yes

And where do you use mysqli?

With vBulletin

http://www.vbulletin.com/docs/html/main/editconfig

Regards
- Tommy

[Dabbler]

With vBulletin

http://www.vbulletin.com/docs/html/main/editconfig

Using mySQL 5.0 and PHP 5.2.
Do you recommend mysqli??

[TommyBALL]

Using mySQL 5.0 and PHP 5.2.
Do you recommend mysqli??

JelSoft recommends mysqli in the documentation

http://www.vbulletin.com/docs/html/main/mysqli

MySQLi is an improved database layer for PHP 5 and MySQL 4.1+. It is strongly recommended that MySQLi be used if your MySQL server is at version 4.1 or higher.

[Dabbler]

The VB manual on the config file at:

http://www.vbulletin.com/docs/html/main/editconfig

states regarding the $config['Database']['dbtype'] setting:

If you are using PHP5 in combination with MySQL 4.1.x you may want to change this variable to 'mysqli'

which implies to me that it is (a) specific to MySQL 4.1.x and (b) optional. Hence my question.

[Colin F]

It's optional, but if you have the possibility, then we recommend it.