[rt-users] rt/mysql crashes [known cause?]

[Adam Herscher]

Greetings,

I'm running rt 3.0.2pre6 (apache+mod_perl) and mysql 4.0.13, both on 
openbsd 3.2.

After clicking through the web interface for several minutes, rt 
would become unable to generate pages, and would log the following error:

[Mon May 26 23:46:31 2003] [warning]: 
DBI->connect(dbname=rt3;host=x.x.x.x;port=3306) failed: Too many 
connections at 
/usr/local/libdata/perl5/site_perl/DBIx/SearchBuilder/Handle.pm line 119
 (/usr/local/rt/lib/RT.pm:226)

Restarting apache would clear up the connections, but then (after the 
httpd restart) the mysql process would begin to spin out of control:

  PID USERNAME PRI NICE  SIZE   RES STATE WAIT     TIME    CPU COMMAND
 1921 mysql     64    0   62M   21M run   -        1:51 99.02% mysqld

I found the following threads which seem to describe the same problem:

http://lists.fsck.com/pipermail/rt-devel/2002-October/002581.html
http://lists.fsck.com/pipermail/rt-devel/2002-November/002773.html

After adding Stanislav Sinyagin's recommended DESTROY() subroutine to 
SearchBuilder 0.82's Handle.pm, rt/apache no longer leave open stale 
database connections (which were eventually reaching the mysql default max 
value of 100 -- then resulting in the crashes).

It's too soon to tell whether any new problems have cropped up since the 
addition, but I'm keeping an eye out.

It's hard to tell what conditions must be met to trigger this bug, but 
between the threads above and my experience, it's occurred on at least 
openbsd, freebsd, and debian linux with varying software versions.

Jesse & team, what are your thoughts?

Regards,

- Adam