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Re: [multitail] Re: WARNING




Wild, wild guess... rotating log files?


On Mon, Apr 03, 2006 at 12:39:10PM -0700, Michael McDaniel wrote:
> 
> Thanks for the info, Tony.
> 
> The machine is a SuSE 9.i-don't-remember which, prior to today,
> had been running for about seven months with no downtime except
> the brief exceptions when I'd do a postfix or policy server
> upgrade (though then only long enough to restart or reload the
> upgraded piece).  It is a multi-virtual-domain email server using
> postfix, courier imaps/pops and offering login via Apache/SquirrelMail.
> The pertinent pieces were compiled using gcc v3.3.4 (a bit of an
> old version though I've never seen any problems).  Oh, and mysql
> from a MySQL rpm.
> 
> I do use screen.  I am familiar with reattaching though have not
> taken advantage of using it on remote machines over ssh. I will
> look into that.
> 
> At the end of your post you state 
> 
>       "there are ways to avoid zombie processes"
> 
> though I went to your link and did not see any information about it.
> What ways do you have in mind?
> 
> 
> One new possibility occurs to me and it has the feel of "sure,
> that must be it" but I need a real technical reason to be 
> satisfied it *is* it.  Also, it seems to me that I should have
> had problems sooner than today if this is the cause.  "This" is
> that the copy of multitail running on the SuSE machine was copied
> over to it from my Debian (Ubuntu) laptop.
> 
> Two things are obvious to me:
> 1) The libraries must have *some* compatibility else it would never
>    have run.
> 
> 2) The libraries are different to some degree between the machines.
>    (Actually, this is not obvious, it is my belief because my laptop
>     is a newer Debian vs. an older SuSE).
> 
> And now, doing the following, maybe there is no difference in the
> libraries at all.  
> 
> libutil could be a problem; what function calls are called from libutil?
> 
> 
> ON THE SuSE MACHINE  (this multitail was compiled on the Debian machine)
> 
> $ ldd multitail
>         linux-gate.so.1 =>  (0xffffe000)
>         libpanel.so.5 => /usr/lib/libpanel.so.5 (0xb7f6b000)
>         libncurses.so.5 => /lib/libncurses.so.5 (0xb7f2a000)
>         libutil.so.1 => /lib/tls/i686/cmov/libutil.so.1 (0xb7f25000)
>         libm.so.6 => /lib/tls/i686/cmov/libm.so.6 (0xb7f02000)
>         libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7dd4000)
>         libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0xb7dd0000)
>         /lib/ld-linux.so.2 (0xb7f7e000)
> 
> $ ls -gGl /usr/lib/libpanel.so.5
> lrwxrwxrwx  1 15 2005-03-26 19:13 /usr/lib/libpanel.so.5 -> libpanel.so.5.4
> 
> $ ls -gGl /lib/libncurses.so.5
> lrwxrwxrwx  1 17 2005-03-26 19:13 /lib/libncurses.so.5 -> libncurses.so.5.4
> 
> $ ls -gGl /lib/tls/i686/cmov/libutil.so.1
> /bin/ls: /lib/tls/i686/cmov/libutil.so.1: No such file or directory
> 
> $ ls -gGl /lib/tls/i686/cmov/libm.so.6
> /bin/ls: /lib/tls/i686/cmov/libm.so.6: No such file or directory
> 
> $ ls -gGl  /lib/tls/i686/cmov/libc.so.6
> /bin/ls: /lib/tls/i686/cmov/libc.so.6: No such file or directory
> 
> $ ls -gGl /lib/tls/i686/cmov/libdl.so.2
> /bin/ls: /lib/tls/i686/cmov/libdl.so.2: No such file or directory
> 
> $ ls -gGl /lib/ld-linux.so.2
> lrwxrwxrwx  1 11 2005-03-26 19:13 /lib/ld-linux.so.2 -> ld-2.3.3.so
> 
> 
> If calls were made to the missing libraries I would expect immediate
> problems.
> 
> QUESTIONS:
> 1) Anyone know the definitive command to check which glibc is being
>    used on the respective machines? 
> 
> 2) Anyone have a definitive reason why compiling/copying *would* be
>    a problem?
> 
> If I can find a definitive technical answer to #2 I will feel safe in
> recompiling directly on the SuSE machine and using multitail.  However,
> I can't afford to bring down this machine again anytime in the near
> future.
> 
> I am leaning towards the compile/copy as being the problem though I
> would like to understand exactly why.  I have recompiled multitail
> on the SuSE machine and now ...
> 
> 
> $ ldd multitail
>         linux-gate.so.1 =>  (0xffffe000)
>         libpanel.so.5 => /usr/lib/libpanel.so.5 (0x4001f000)
>         libncurses.so.5 => /lib/libncurses.so.5 (0x40024000)
>         libutil.so.1 => /lib/libutil.so.1 (0x40069000)
>         libm.so.6 => /lib/tls/libm.so.6 (0x4006d000)
>         libc.so.6 => /lib/tls/libc.so.6 (0x40090000)
>         /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
> 
> $ ls -gGl /usr/lib/libpanel.so.5
> lrwxrwxrwx  1 15 2005-03-26 19:13 /usr/lib/libpanel.so.5 -> libpanel.so.5.4
> 
> $ ls -gGl /lib/libncurses.so.5
> lrwxrwxrwx  1 17 2005-03-26 19:13 /lib/libncurses.so.5 -> libncurses.so.5.4
> 
> $ ls -gGl /lib/libutil.so.1
> -rwxr-xr-x  1 12643 2004-10-05 05:08 /lib/libutil.so.1
> 
> $ ls -gGl /lib/tls/libm.so.6
> -rwxr-xr-x  1 174623 2004-10-05 05:21 /lib/tls/libm.so.6
> 
> $ ls -gGl /lib/tls/libc.so.6
> -rwxr-xr-x  1 1359489 2004-10-05 05:21 /lib/tls/libc.so.6
> 
> $ ls -gGl /lib/ld-linux.so.2
> lrwxrwxrwx  1 11 2005-03-26 19:13 /lib/ld-linux.so.2 -> ld-2.3.3.so
> 
> (I still have not run it to try and reproduce the problem!)
> 
> 
> I would really like to find out exactly what happened because multitail
> is very useful for keeping track of my remote charges.
> 
> thanks, all,
> 
> 
> ~Michael
> 
> 
> 
> 
> On Mon, Apr 03, 2006 at 02:56:35PM -0400, tony summerfelt wrote:
> > On Mon, 3 Apr 2006 11:30:01 -0700, you wrote:
> > 
> > 
> > >  Is it possible that ^Z (placing multimail in background) could
> > >  cause problems?
> > 
> > doesn't unexpected termination (ie. not waiting for the child process)
> > of a parent process cause zombies?
> > 
> > out of curiosity is this a redhat machine? i know there was  a problem
> > with some verisons of redhat ignoring the SIGCHLD signal... and
> > multitail uses that in it's ui.c code. if you send it to the
> > background that COULD be the problem.
> > 
> > i always use 'screen' myself. i use "screen -S mt" and then run
> > multitail.
> > 
> > when i connect via ssh on another machine i can do:
> > screen -D -R mt
> > 
> > and i get my multitail session back. 
> > 
> > the screen/ssh combination is very nice if you're never around a
> > server machine :)
> > 
> > there are ways to avoid zombie processes
> > 
> > http://home.cogeco.ca/~tsummerfelt1
> > telnet://ventedspleen.dyndns.org
> > 
> 
> > --------------------------------------------------------------------------------------
> > This message was sent through the MultiTail mailinglist (www.vanheusden.com/multitail)
> 
> 
> -- 
> Michael McDaniel
> Portland, Oregon, USA
> http://autosys.us
> +1 503 283 5284
> 
> 
> 
> --------------------------------------------------------------------------------------
> This message was sent through the MultiTail mailinglist (www.vanheusden.com/multitail)

-- 
Pedro Alves
pedro.alves@zmail.pt