mysql signal 11

[Jeremy Chadwick]

On Wed, Jul 12, 2006 at 06:43:01PM +0200, Koen Martens wrote:
> Hi All,
> 
> Recently came across:
> 
> http://lists.freebsd.org/pipermail/freebsd-ports/2005-April/022667.html
> 
> I'm not on the the freebsd-ports list, so i don't know if this has
> been followed up properly. Anyway, I had the same problem on one of
> my freebsd jails.
> 
> I tried mysql-5.0.22 as a freebsd package, tried the official mysql
> binary for freebsd-6.x and tried a fresh compile from the mysql
> source tarball, all with the same problem.
> 
> I then tried the 4.1 binary from mysql.com, that worked fine, also
> tried the 5.1 beta binary from mysql.com, and that was fine too.
> 
> Not sure what to do with this info, i'll probably try to make a
> test-case for it and submit it to the mysql bug system.
> 
> Just thought i'd update y'all.
> 
> Gr,
> 
> Koen
> 
> Ps: Uzi, if the list does not accept my post, could you please
> forward the info there??

I've experienced this exact problem (with current versions of
MySQL, as well as older (4.0 and 4.1)).  I ended up fixing it by
doing the following on our 5.5-STABLE (which has been world'd
since 5.2-STABLE, in case there's any concern):

1) Kernel: use SCHED_4BSD not SCHED_ULE

2) Kernel: use ADAPTIVE_GIANT

2) Kernel: Increasing size limits using loader.conf variables:
     kern.maxdsiz="805306368"
     kern.dfldsiz="805306368"
     kern.maxssiz="134217728"
   (The machine has 1GB RAM; note the sizes are topped out at
   768MB, since that could induce a kernel panic due to
   memory exhaustion)

3) MySQL port:
     WITH_LINUXTHREADS -- didn't solve the problem so I
                          don't bother with it
     WITH_PROC_SCOPE_PTH -- makes no difference

4) MySQL tuning: increased packet size (which fixed segfault;
   possibly related?)
     set-variable  = max_allowed_packet=32M

5) MySQL tuning: didn't require much, but we did set some higher
   limits for join/sort/read_buffer_size (128M).

-- 
| Jeremy Chadwick                                 jdc at parodius.com |
| Parodius Networking                        http://www.parodius.com/ |
| UNIX Systems Administrator                   Mountain View, CA, USA |
| Making life hard for others since 1977.               PGP: 4BD6C0CB |