Re: [2.4.17/18pre] VM and swap - it's really unusable

Petro
2002-01-07T07:16:08Z

On Sat, Jan 05, 2002 at 04:44:05PM +0100, Stephan von Krawczynski wrote:
> On Sat, 5 Jan 2002 01:24:42 -0800
> Petro <petro@auctionwatch.com> wrote:
>
> > "We" (Auctionwatch.com) are experiencing problems that appear to be
> > related to VM, I realize that this question was not directed at me:
>
> And how exactly do the problems look like?

After some time, ranging from 1 to 48 hours, mysql quits in an
unclean fashion (dies leaving tables improperly closed) with a dump
in the mysql log file that looks like:

> Here is the stack dump:
> 0x807b75f handle_segfault__Fi + 383
> 0x812bcaa pthread_sighandler + 154
> 0x815059c chunk_free + 596
> 0x8152573 free + 155
> 0x811579c my_no_flags_free + 16
> 0x80764d5 _._5ilink + 61
> 0x807b48d end_thread__FP3THDb + 53
> 0x80809cc handle_one_connection__FPv + 996

Which the Mysql support team says appears to be memory corruption.
Since this has happened on 4 different machines, and one of them had
memtest86 run on it (coming up clean), they seem (witness Sasha's
post) to think this may have something to do with the memory
handling in the kernel.

I haven't run it on a kernel that has debugging enabled yet,
partially because I've been tracing a completely unrelated problems
with our hard drives (IBM GXP 75G drives made in Hungary during the
first 3 months of 2001), and partially because the only way to get
this to happen is to put the database in production, which results
in a crash, which takes our site offline, which costs us money and
pisses off our users. Right now we're running on a sun e4500, and
it's stable, so until we get the other problem worked out, we're
waiting to see on this one.

--
Share and Enjoy.