Xymon Mailing List Archive search

Weird application freeze problem

list Ralph Mitchell
Mon, 8 Sep 2008 22:20:29 -0500
Message-Id: <user-a5187846bd79@xymon.invalid>

Does your ntpdate have the  -B option??  If so, it can make the adjustment
slowly.

From the Gentoo Linux manpage:

       -B     Force  the  time  to always be slewed using the adjtime()
system
              call, even if the measured offset is greater than +-128 ms.
The
              default  is  to step the time using settimeofday() if the
offset
              is greater than +-128 ms. Note  that,  if  the  offset  is
much
              greater than +-128 ms in this case, that it can take a long
time
              (hours) to slew the clock to  the  correct  value.  During
this
              time. the host should not be used to synchronize clients.

From the NOTES section of the adjtime(3) man page:

       The adjustment that adjtime() makes to the clock is carried out in
such
       a manner that the clock is always monotonically increasing.  Using
adj-
       time()  to adjust the time prevents the problems that can be caused
for
       certain applications (e.g., make(1)) by  abrupt  positive  or
negative
       jumps in the system time.

Ralph Mitchell


On Mon, Sep 8, 2008 at 10:10 PM, Rich Smrcina <user-cf452ff334e0@xymon.invalid> wrote:
Posting for a friend....

I've been testing out Hobbit in a SLES 10 virtual machine on z/VM.  It is
a monitoring application based off of Big Brother.  So far, it works great
except for one weird thing.  We have a cron task that runs once a night
that does ntpdate to sync the time with an NTP server.  If the time is
in sync, no problem.  However, if the time is out of sync and is adjusted,
Hobbit freezes.  The tasks still exist, but they just stop doing anything.
Apache continues to display the same web page without an update.  Stopping
the Hobbit daemon doesn't help, in fact, it does nothing.  The tasks never
stop.  I have to recycle the entire system in order to free it up.

Has anyone seen a problem similar to this?  Any ideas?

--
Rich Smrcina
VM Assist, Inc.
Phone: XXX-XXX-XXXX
Ans Service:  XXX-XXX-XXXX
user-61add9955ef9@xymon.invalid
http://www.linkedin.com/in/richsmrcina

Catch the WAVV!  http://www.wavv.org
WAVV 2009 - Orlando, FL - May 15-19, 2009