Spoken too soon...
Yesterday MySQL died again... there is nothing in the log files... (be
it mysqld.log, .err, or /var/log/messages).
The hosting provider is running an application called 'big-brother'
and a lot of sef-faults appear in the logs from this. I don't know if
thins is the cause... if this application is faulting mysql also...
The behaviour: the whole machine freezes... all that can be done is to
hit the RESET button on the machine !
Friday we downgraded from 5.0 to 4.1. At first we compiled the MySQL
server ourselvs... next we deleted it and installed a RPM version...
It appears we hit bug 15815... (http://bugs.mysql.com/bug.php?id=15815)...
So be aware with innodb_thread_concurency on 64bit machines...
Below are some values as an orientation... for
innodb_thread_concurency value per machine workload (at arround 600
simultaneous connections... all used):
innodb_thread_concurency / CPU-workload
8 / 90%
4 / 75 - 85%
3 / 60 - 70%
2 / 25%
So set it lower... lower... lower... when I left the office friday my
colleagues were still working at this... I'll keep you all updated !
Senior Web Developer