Description:
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For long time I was using multithreaded scripts (pcntl module). Each script was using their own connection to MySQL server (mysql module). They are working properly on FC1 - FC4 linuxes (PHP 4.3.11 - 5.0.4). I tried for the first time to tun them on FC5 which includes standard rpm packages - PHP 5.1.4 in this case (iptables and selinux turned off).

I noticed that my threads fail with message "server has gone away" when using "mysql_select_db. The behaviour is the same regardless if it is connection via unix socket file, tcp/ip connection to localhost or some remote IP address. It does not matter what MySQL server version I am connecting to (tried with 3.23.58 - 5.0.22)

I tried also switch to "mysqli" module on FC5 and the script started working properly again so I assume only "mysql" module is affected.

I do not have major changes to standard php.ini... just max_execution_time=300 and memory_limit=32M. Test script is just a minimal version (without any threads synchronization, etc. stuff).

Please help :-)

Reproduce code:
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http://www.buleksoft.pl/mysql_pcntl_test.html

Expected result:
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[root@host ~]# php -q test.php
Forking thread number 0
Thread 0 doing some mysql tasks
Forking thread number 1
Thread 1 doing some mysql tasks
Forking thread number 2
Thread 2 doing some mysql tasks
Forking thread number 3
Thread 3 doing some mysql tasks


Actual result:
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[root@host ~]# php -q test.php
Forking thread number 0
Thread 0 doing some mysql tasks
Forking thread number 1
Thread 1: Could not select DB because MySQL server has gone away
Forking thread number 2
Thread 2: Could not select DB because MySQL server has gone away
Forking thread number 3
Thread 3: Could not select DB because MySQL server has gone away