[ldm-users] 20091007: Problems ingesting NOAAPort nwstg2 GRIB2 data

• To: LDM Users <ldm-users@xxxxxxxxxxxxxxxx>
• Subject: [ldm-users] 20091007: Problems ingesting NOAAPort nwstg2 GRIB2 data
• From: Tom Yoksas <yoksas@xxxxxxxxxxxxxxxx>
• Date: Wed, 07 Oct 2009 17:12:24 -0600

Users of the Unidata's NOAAPort ingest package and IDD datastreams:

Like others who have responded to this list, we observed the first
problem with NOAAPort ingest using our noaaport-1.3.0 packge today at
approx. 14:30 UTC.

According to the administrative message sent in NOAAPort and forwarded
to this list by Gilbert Sebenste:

   THERE WILL BE AN OPERATIONAL TEST OF THE AWIPS
   NETWORK CONTROL FACILITY (NCF) BACKUP SERVERS.
   NCF SERVER OPERATIONS WILL BE SWITCHED FROM THE
   PRIMARY AWIPS NCF (ANCF) IN SILVER SPRING, MD TO THE
   BACKUP NCF (BNCF) AT FAIRMONT, WV.   THE SWITCH IS
   SCHEDULED FOR WEDNESDAY, 7 OCTOBER AT 1415 UTC.
   ...

our problems began about 15 minutes after the scheduled test of the NCF
backup servers.  We are led to believe that there is some subtle
difference in a small subset of the products being sent from the AWIPS
primary NCF (ANCF) in Silver Springs, MD and the backup NCF (BNCF) in
Fairmont, WV, and that difference is triggering a latent bug in our
NOAAPort ingest code.  Our observation is that the products that are
causing the ingest failures are GRIB2 messages being sent in the nwstg2
PID.

Sites using Unidata NOAAPort ingest code who wish to circumvent the ingest
failures that lead to LDM exiting should comment out the ingest and
processing of the nwstg2 PID data from their ~ldm/etc/ldmd.conf files:

- comment the following lines in ~ldm/etc/ldmd.conf:

  exec    "dvbs_multicast -m 224.0.1.3"
  exec    "readnoaaport   -m 224.0.1.3"

- restart the LDM

  ldmadmin restart

Those same users can access these data in the NGRID feed from the
toplevel IDD relay node that we operate here in UCAR,
idd.unidata.ucar.edu.

We are currently working to track down and fix the bug that is
resulting in 'readnoaaport' segmentation violations for the small
subset of nwstg2 products.  Users who wish to be notified when the bug
has been isolated and fixed should send email to:

support-noaaport@xxxxxxxxxxxxxxxx

We apologize for the problems being experienced...

Cheers,

Tom
--
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* Tom Yoksas                                            UCAR Unidata Program *
* (303) 497-8642 (last resort)                                 P.O. Box 3000 *
* yoksas@xxxxxxxxxxxxxxxx                                  Boulder, CO 80307 *
* Unidata WWW Service                            http://www.unidata.ucar.edu/*
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