[ale] load issue

Jerry Yu jjj863 at gmail.com
Thu Jun 22 12:01:08 EDT 2006


'load' as reported by 'uptime' is not exactly CPU usage per se. It is
about runnable processes waiting i to be scheduled.

man page for a debian package (cpu_sup) has some good discussion on
different ways to report system load.
http://manpages.debian.net/cgi-bin/display_man.cgi?id=f6878da95fce38a745d90ff261aba635&format=plain

On 22 Jun 2006 07:27:57 -0400, Christopher Fowler
<cfowler at outpostsentinel.com> wrote:
> I had a problem like this on FC2 and ran into an interesting situation.
> My load would be at 2+ and could rise but top showed nothing.  I was
> perplexed.  Here the kernel said some processes were using up CPU and
> top could not list those.  The culprit was a few threads in tomcat.
>
> Apparently we had some code written that did not understand that when
> read() returns 0 it means the other end has terminated the connection.
> Therefor Java IO was looping as fast as possible because it thought it
> had something to read on a socket.  read() would return 0 and it would
> keep doing this.  After a few of these threads the system would go to a
> crawl.  Strace was the _only_ way I found this.  I killed a few
> processes trying to see which one was a problem and then I attached to
> java and saw what was going on.  Restart tomecat and load went to 0.00.
> It may be the way the FC2 kernel handled threads that confused top?  I
> do not know.  The problem was that the JVM running tomcat was eating all
> my CPU and top was useless in telling me this information.
>
>
> On Thu, 2006-06-22 at 06:02, David Corbin wrote:
> > On Thursday 22 June 2006 12:53 am, Benjie wrote:
> > > do you have any zombie, or otherwise dead processes?  I have seen my
> > > load average go up mysteriously ( no real cpu load) when there was a
> > > dead process that had a file locked.
> >
> > What's the best way to tell?
> >
> > David
> > _______________________________________________
> > Ale mailing list
> > Ale at ale.org
> > http://www.ale.org/mailman/listinfo/ale
>
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://www.ale.org/mailman/listinfo/ale
>



More information about the Ale mailing list