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

[IDD #KUZ-323197]: IDD data feed issues

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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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: [IDD #KUZ-323197]: IDD data feed issues
  • Date: Wed, 06 Jan 2010 16:49:33 -0700
Hi Garry,

re:
> My name is Garry Patterson and I work at the US Air Force Academy in
> the Meteorology Lab.

Yours is a timely email.  We were going to be contacting someone at the
USAF Academy to discuss data feed problems that we have been seeing
here at UCAR/Unidata.

re:
> I have an LDM server (meteo.usafa.edu) that makes
> a direct TCP connection to idd.unidata.ucar.edu. to ingest GEMPAK data
> from you.  When I returned from the Christmas break, I discovered the
> LDM had stopped ingesting the data.  I notified my network operations
> folks, who said they could see data (requests) leaving, but had very
> little coming back.  He said it looked as if the unicar servers were
> rejecting the requests.

Actually, the problem looks like it has something to do with your
firewall.  Here is the email our system administrator recently sent us
on what he has been seeing with connections from you:

  "For a while now, I've noticed that our friends at the AFA are causing
   a unique problem on the IDD cluster.  Their "firewall" system seems to be
   disconnecting and reconnecting frequently, in this case to uni7.  At any
   given time, they have about 120-170 connections, in various states of
   setup, establishment, or teardown.  The ldm log file shows one of these
   messages every two to twenty seconds;

   Dec 29 10:56:54 uni7 firewall.usafa.edu[7789] NOTE: Connection from client 
LDM silent for 720 seconds
   Dec 29 10:56:54 uni7 rpc.ldmd[5649] NOTE: child 7789 exited with status 110

   They don't seem to be reporting stats, otherwise we could see how much
   data is actually being transferred.  Can you take a look?"

Can you get together with your network folks to see if there was any
change made over the holiday break to the what the LDM is allowed to
receive data?  I seem to recall that LDM feed requests are being
handled by a proxy on the AFA firewall (but I may be remembering
incorrectly).

re:
> Can you tell me if there is a subscription I have unintentionally let
> lapse or if you are having issues with data flow?

There is no lapse on your part.  The problem seems to be caused by
the setup there that proxys/forwards the feed requests.  We need
your network folks to take a hard look on your side to see what
may have changed recently.

Cheers,

Tom
--
****************************************************************************
Unidata User Support                                    UCAR Unidata Program
(303) 497-8642                                                 P.O. Box 3000
address@hidden                                   Boulder, CO 80307
----------------------------------------------------------------------------
Unidata HomePage                       http://www.unidata.ucar.edu
****************************************************************************


Ticket Details
===================
Ticket ID: KUZ-323197
Department: Support IDD
Priority: Normal
Status: Closed