[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: LDM Status Report Question

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: Re: LDM Status Report Question
  • Date: Fri, 12 Jan 2001 10:15:39 -0700
> Hi Allan,
> 
> > I've experienced a problem using LDM and was wondering if you might have
> > any insight or comments about how to resolve, or identify the problem.
> > I'm using LDM (v 5.0.8) to distribute files to three receivers within
> > the NWS WAN.  We recently experienced a problem where one of the three
> > systems stopped receiving files while the other two system continued to
> > receive files.  The affected system could ping, but not ldmping, our
> > system.  We could ping and ldmping their system.  This condition
> > persisted even after they restarted their LDM. After we stopped and
> > started LDM at our end, the problem went away.  I ran an ldmadmin check,
> > the results of which are below.
>  ...

I just wanted to add another possibility to this discussion.

If you followed the ldm-users list this morning you might have seen that
a user was having a problem.  The symptoms were that his ldm would "just
stop running".  He finally discovered that his ldmd.conf file was losing
it's contents - it would morph into a 0 length file.  Replacing the file
fixed the problem.  It's interesting to me to find that the ldm requires
that file to be present continuously, not just on startup.

Then, the question became: how did the file get zero'd out?  It turns
out that he had written his own failover script, and in it he had
confused ldmd.log with ldmd.conf.  Presumably, when his script detected
a downtime of the upstream host it made the swap.  This resulted in what
appeared to be a random zeroing of the file.

FYI.

Anne
-- 
***************************************************
Anne Wilson                     UCAR Unidata Program            
address@hidden                 P.O. Box 3000
                                  Boulder, CO  80307
----------------------------------------------------
Unidata WWW server       http://www.unidata.ucar.edu/
****************************************************