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Bug #14886 Access Violation in error handler with PEAR DB (ISAPI)
Submitted: 2002-01-06 06:15 UTC Modified: 2002-11-19 01:00 UTC
Votes:3
Avg. Score:4.7 ± 0.5
Reproduced:3 of 3 (100.0%)
Same Version:1 (33.3%)
Same OS:2 (66.7%)
From: jlim at natsoft dot com dot my Assigned:
Status: No Feedback Package: IIS related
PHP Version: 4.1.1 OS: Win2000
Private report: No CVE-ID: None
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 [2002-01-06 06:15 UTC] jlim at natsoft dot com dot my
I ran ApacheBench on a PEAR DB script (see below), and IIS (ISAPI mode) will die eventually. It is so bad that often "iisreset" is unable to restart IIS. 

The ab command I used:

ab -n10000 -c10 <url>

with the following results:

This is ApacheBench, Version 1.3c <$Revision: 1.45 $> apache-1.3
Copyright (c) 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright (c) 1998-2000 The Apache Group, http://www.apache.org/

Server Software:        Microsoft-IIS/5.0
Server Hostname:        jaguar
Server Port:            80

Document Path:          /lens/adodb/peartest.php
Document Length:        142 bytes

Concurrency Level:      10
Time taken for tests:   269.158 seconds
Complete requests:      10000
Failed requests:        5272
   (Connect: 0, Length: 5272, Exceptions: 0)
Non-2xx responses:      1868
Total transferred:      1891906 bytes
HTML transferred:       769177 bytes
Requests per second:    37.15
Transfer rate:          7.03 kb/s received

Connnection Times (ms)
              min   avg   max
Connect:        0     0     5
Processing:     2   268  2771
Total:          2   268  2776


The interesting thing is that the crash only happens when an invalid SQL statement is entered in the script below(notice the column "badcolumn" which does not exist). If a valid SQL statement is entered ("badcolumn" is removed), no crash occurs, and ApacheBench runs fine. 

So I guess it is some problem with PHP's error-handler or MySQL extension not being thread safe. No dll extensions were installed. Standard pre-compiled PHP downloaded from php.net was used.

John Lim

======================= THE SCRIPT ===================

<?php

include "DB.php";

$DBNAME = 'PEAR DB';

$dsn = "mysql://root:@localhost/northwind";
$db = &DB::Connect($dsn);

$rs = $db->query('select badcolumn,productid,productname,unitsinstock,unitprice from products');
while (DB_OK === $rs->fetchInto($fields)) {
	$id=$fields[0];
	$name=$fields[1];
	$unitsinstock=$fields[2];
	$unitprice=$fields[3];
	
		print "$id, $name, $unitsinstock, $unitprice<br>";
}

$rs->free();

?>

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 [2002-01-07 01:20 UTC] jlim at natsoft dot com dot my
I have simplified the crash to the following script (note that $obj is null). The bug does not happen when $testmysql = false.

<?php

error_reporting(E_ALL);
$testmysql = true;

print "<br>test start";
if ($testmysql) {
	$conn = mysql_connect('localhost','root');
}
$obj->run();

print "<br>test end";

?>

I had to run "ab -n20000 -c10 <url>" several times before problems started to occur on a W2k IIS server receiving no other visitors and had just been restarted.

This is ApacheBench, Version 1.3c <$Revision: 1.45 $> apache-1.3
Copyright (c) 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Copyright (c) 1998-2000 The Apache Group, http://www.apache.org/

Server Software:        Microsoft-IIS/5.0
Server Hostname:        jaguar
Server Port:            80

Document Path:          /php/err.php
Document Length:        145 bytes

Concurrency Level:      10
Time taken for tests:   184.950 seconds
Complete requests:      20000
Failed requests:        556
   (Connect: 0, Length: 556, Exceptions: 0)
Non-2xx responses:      555
Total transferred:      5504927 bytes
HTML transferred:       2847858 bytes
Requests per second:    108.14
Transfer rate:          29.76 kb/s received

Connnection Times (ms)
              min   avg   max
Connect:        0     0    22
Processing:     4    90   466
Total:          4    90   488

 [2002-11-03 11:16 UTC] iliaa@php.net
Please try using this CVS snapshot:

  http://snaps.php.net/php4-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-latest.zip


 [2002-11-19 01:00 UTC] php-bugs at lists dot php dot net
No feedback was provided for this bug for over 2 weeks, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".
 
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