#38228 [NEW]: Pcntl based parallel threads loose connection to MySQL server

From: piotr at bulczak dot name Operating system: Fedora Core 5 Linux PHP version: 5.1.4 PHP Bug Type: MySQL related Bug description: Pcntl based parallel threads loose connection to MySQL server Description: ------------ 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: --------------- http://www.buleksoft.pl/mysql_pcntl_test.html Expected result: ---------------- [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: -------------- [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 -- Edit bug report at http://bugs.php.net/?id=38228&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=38228&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=38228&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=38228&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=38228&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=38228&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=38228&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=38228&r=needscript Try newer version: http://bugs.php.net/fix.php?id=38228&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=38228&r=support Expected behavior: http://bugs.php.net/fix.php?id=38228&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=38228&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=38228&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=38228&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=38228&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=38228&r=dst IIS Stability: http://bugs.php.net/fix.php?id=38228&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=38228&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=38228&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=38228&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=38228&r=mysqlcfg