Date: Mon, 14 Jun 2004 11:15:34 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: Lasse Laursen <laursen@netgroup.dk> Cc: freebsd-threads@freebsd.org Subject: Re: Possible Threading problem with -CURRENT / MySQL? Message-ID: <Pine.BSF.4.21.0406141107440.30464-100000@InterJet.elischer.org> In-Reply-To: <01c301c45239$940781f0$6401a8c0@animal>
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On Mon, 14 Jun 2004, Lasse Laursen wrote:
>
> 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.
This does suggest a bug in MySQL, but let's investigate anyhow..
>
> 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.
the output of "ps -alxH might be useful.
also:
do you have teh kernel debugger compiled into the kernel?
(option DDB)
if so..
note the PID of the process
sysctl debug.enter_debugger=ddb
[you are now in the debugger]
ps
[note the Thread address of the threads that seem to be blocking things]
(I may ask for specific threads after seeing the 'ps' output)
do
show thread {address}
to get a stack backtrace of those threads.
if possible use a serial console to do all this.. That way you can log
it all.
to make a serial console, connect 2 machines com1 by a null-modem cable.
on the other machine do:
script
tip com1
on the SQL machine add
console="comconsole"
into /boot/loader.conf and reboot
all console out put from teh boot-loader-on will now go to teh serial
port and appear in teh 'tip' output. (which is being logged by the
'script' command).
julian
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