Comments on: How we enabled threading in MySQL http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/ Stay curious! Thu, 02 May 2013 12:36:53 +0000 hourly 1 http://wordpress.org/?v=3.5.1 By: LC http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/#comment-12886 LC Thu, 02 Aug 2007 22:54:46 +0000 http://www.xaprb.com/blog/?p=196#comment-12886 Hi, I have a problem related to this subject . We use a linux VPS(Virtual Private Server) running CentOS 4.5 and mysqld 5.0.41 . When the VPS is restarted mysqld it’s running at boot time with NPTL (threads don’t have pid so they don’t appear in top, ‘ps aux’ and others, but you can see them using ps -eLf for example. We have only one mysqld process running). In this case, the server is running great, without any problems.
But mysqld is restarted (or I restart the VPS without starting mysqld at boot, start mysqld after the boot sequence was completed) , we’ll have lots of mysqld processes, like using linuxthreads implementation (LinuxThreads has a hack to make threads visible as separated processes). In this LinuxThreads ‘state’, the mysqld server restart will fail(60 sec timeout while trying to do
/bin/kill -0 “$MYSQLPID”) . Also, the server will crush in the next 2 days.
I’m not sure if it’s a virtualization/kernel issue.

GNU_LIBPTHREAD_VERSION->linuxthreads-0.10

Thanks

]]> By: Xaprb http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/#comment-3926 Xaprb Tue, 06 Feb 2007 13:11:06 +0000 http://www.xaprb.com/blog/?p=196#comment-3926 Yes, the H key toggles showing NPTL threads in top.

]]> By: Jan http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/#comment-3908 Jan Mon, 05 Feb 2007 16:21:06 +0000 http://www.xaprb.com/blog/?p=196#comment-3908 Wow; thanks a bunch. I’ve been wrecking my brain on this problem for months! I had a hunch it had something to do with different library implementations. But now I understand my ps output is normal on my machine, because my machine use NPTL instead of LinuxThreads.
But from what I understand you rebuild glibc and now your top/ps output _does_ show the threads _with_ NPTL? This doesn’t make sense; since you stated one of the things with NPTL is that it doesn’t come up in ps/top?

]]> By: Benedetto http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/#comment-1234 Benedetto Wed, 26 Jul 2006 11:31:23 +0000 http://www.xaprb.com/blog/?p=196#comment-1234 Hi, thank you all, I have few servers and on just one of them I see only one process under TOP, I was scared that my mysql installation was screwed, instead probably it’s just that on this machine I have a different kernel,2.6, and is showing one process as it should.

]]> By: Xaprb http://www.xaprb.com/blog/2006/07/16/how-we-enabled-threading-in-mysql/#comment-1146 Xaprb Thu, 20 Jul 2006 01:09:16 +0000 http://www.xaprb.com/blog/?p=196#comment-1146 Wow, thanks everyone for writing! I am learning a ton now that more people are reading and commenting (I am not that experienced myself). Our CPU utilization certainly went down after we got switched to NPTL, but it must just be that NPTL is more efficient than linuxthreads.

Sorry for the delay in moderating, I was in Turkey for a week!

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