Possible Threading problem with -CURRENT / MySQL?

[Lasse Laursen]

Hi,

I posted this on the 2freebsq-questions" list some time ago but didn't get
any response. Maybe someone on this list can help:

We are running MySQL 4.0.20 on FreeBSD 5.2-CURRENT. The machine is a dual
Xeon with 4GByte of memory with HTT enabled.

Some info about the system:

FreeBSD dbnode3 5.2-CURRENT FreeBSD 5.2-CURRENT #0: Tue Jun  8 14:41:02 CEST
2004     laursen at dbnode3:/usr/obj/usr/src/sys/DBNODE3  i386

the /etc/libmap.conf contains:

libc_r.so.5     libpthread.so.1
libc_r.so       libpthread.so

/etc/make.conf contains:

# -- use.perl generated deltas -- #
# Created: Wed Jun  9 10:18:52 2004
# Setting to use base perl from ports:
PERL_VER=5.8.4
PERL_VERSION=5.8.4
PERL_ARCH=mach
NOPERL=yo
NO_PERL=yo
NO_PERL_WRAPPER=yo

MySQL 4.0.20 was compiled with --without-libwrap (libwrapper seems to be
broken) and WITH_PROC_SCOPE_PTH set to yes.

WE use the SCHED_ULE, and:

# Memory options
options         MAXDSIZ="(1536*1024*1024)"
options         MAXSSIZ="(1024*1024*1024)"
options         DFLDSIZ="(1536*1024*1024)"

The server runs fine until a single thread/query suddenly locks up the
entire MySQL daemon. After that all queries are just queued and a restart of
the daemon is needed to unlock the system. The system itself is stable
enough as far as I can see. 'top' reports a lot of locks (*Giant) so I
assume that it's some weird problem with the threading? We used to use
FreeBSD on non-SMP machines without any problems.

I have tried with linux threads as well but the same problem occurs.

Have anyone experienced any similar problems and found a solution to this
rather weird problem?

Feel free to request any further information about the system/setup and I
will do my best to provide it to the list.

Regards
--
Lasse Laursen · VP, Hosting Technology · NetGroup Processing Aps
St. Kongensgade 40H · DK-1264 Copenhagen K, Denmark
Phone: +45 3370 1526 · Fax: +45 3313 0066

- Don't be fooled by cheap finnish imitations - BSD is the One True Code