Re: Postgresql locks up server - no response at all

On Wed, 2004-08-04 at 13:49 -0700, Kevin Oberman wrote:
> > Date: Wed, 4 Aug 2004 13:34:56 -0700
> > From: Jeremy Chadwick <freebsd_at_jdc.parodius.com>
> > Sender: owner-freebsd-current_at_freebsd.org
> > 
> > I've seen this with our SuperMicro SuperServer 5013C-T, running mysqld.
> > Please note that the server is "heavily loaded" (note the quotes); usually
> > a load of around 0.50 to 1.00 at all times, with mysqld being the top
> > process.  Server runs all latest -CURRENT builds.
> > 
> > Many people over in freebsd-threads mentioned this problem, and recommended
> > all sorts-of different workarounds.  I tried every one available to me,
> > except mucking with PREEMPTION (as I did not feel comfortable tinkering
> > with a random .h file on the box; seemed to be a kernel-related thing,
> > so I'd rather have just an "options" line for it -- I'm conditionally
> > lazy).
> 
> Please note that PREEMPTION is now NOT enabled in CURRENT. scottl
> changed that a day or two ago because of all of these lock-ups. He and
> Julian are listed as working to isolate the problem. Scott believes it's
> in the scheduler. It's not specific to either ULE or 4BSD.
> 
> So cvsup, rebuild the kernel and you should be fine.At least for a while.

Based on this and Jeremy C.'s response it would appear that I should
either try to upgrade my 5.2.1-P8 system to -CURRENT (which is scary
because of the vinum array - root is not mounted on a vinum device, but
the data directory is - will gvinum simply read this correctly? it is a
stripe+mirror array of 4 drives) or start from scratch and go back to
4.10 (STABLE) for a while. I am assuming that the lockups I am seeing
were exacerbated by the PREEMPTION episodes of the past couple weeks? If
I choose the upgrade to -CURRENT, are there any caveats or
recommendations? (besides reading "/usr/src/UPDATING" which I do
religiously anyway)