Description:
------------
Now, in the Web application which we are developing, 
session information is got by Cookie. 
A trouble is not occured by the test of the application in the few clients. 
However, if the load of 200 threads is executed by Microsoft Web Application Stress Tool, 
the value of Cookie may serve as NULL in the about beyond 160-200 sessions, 
and a few error may occur. 
Since the client has sent Cookie if a packet monitor is seen, 
the problem by the side of a server is considered. 

The Web server is using apche1.3.27 on RedHat9(kernel2.4.20-18.9) 
with glibc-2.3.2-27.9.
configure of PHP4.3.2 is performed as follows. 
./configure --enable-trans-sid \
 --with-apxs=/usr/local/apache/bin/apxs \
 --enable-mbstring \
 --with-mysql=/usr/local/mysql 

MaxClient of apache(in httpd.conf) is set as 50. 
In php.ini, a change of those other than [mbstring] is not made. 
(session.cookie_lifetime is also set to 0. register_globals is also set to "Off")

Does anybody know where this null comes from? 


Reproduce code:
---------------
This program code is below.
 function sess_get_id(&$ssid) {
     global $HTTP_COOKIE_VARS;
     $ret  = NORMAL_END;
     $ssid = $HTTP_COOKIE_VARS[COOKIE_NAME];
     if (chk_ssid($ssid) == true) {
         $ret = NORMAL_END;
     } else {
         $ret = NULL_VALUE;
         return $ret;
     }
 }

Expected result:
----------------
We expect $HTTP_COOKIE_VARS is not NULL.


Actual result:
--------------
We set COOKIE value by setcookie function.
But, parhaps, we can't get a $HTTP_COOKIE_VARS value while a high stress has been the web server.