[CONDUIT #OYS-240819]: SD Mines LDM Server (Conduit: not all grib messages coming through)

Hi Bill,

First, I drove your email into our inquiry tracking system so that
others can jump in to help if/when appropriate.

re:
> We've been having some trouble with not all fields coming through the
> CONDUIT feed for our real time wrf for the nam212 and nam218 feeds.  We
> get most of them but there is the odd grib 'slab' or two that doesn't
> get to us.

A quick look at the CONDUIT latencies being reported by squall:

http://rtstats.unidata.ucar.edu/cgi-bin/rtstats/iddstats_nc?CONDUIT+squall.ias.sdsmt.edu

strongly suggests that something significant wrt the network bandwidth
occurred yesterday!

Questions:

- did students recently return, and their increased Internet use cut
  down on what is available to your department/squall?

- or, perhaps some bandwidth limiting was imposed on the TCP connections
  to/from squall?

- when we worked on squall this summer, the comment was made that it
  has Gbps connectivity, but this no longer seems to be the case

  Has something changed there?

re:
> Is there something that can be tweaked to get that fixed?

The REQUEST for CONDUIT in the LDM configuration file, ~ldm/etc/ldmd.conf,
could be split into mutually-exclusive sub-REQUESTs, and this would
probably help reduce the latencies _if_ the cause of the latencies is
artificial bandwidth limiting imposed on a per-connection basis.

Here is an example of splitting a CONDUIT REQUEST into 5 mutually-exclusive
ones as an example of how this is done:

change:

request CONDUIT ".*" idd.unidata.ucar.edu

to:

request CONDUIT "[09]$" idd.unidata.ucar.edu
request CONDUIT "[18]$" idd.unidata.ucar.edu
request CONDUIT "[27]$" idd.unidata.ucar.edu
request CONDUIT "[36]$" idd.unidata.ucar.edu
request CONDUIT "[45]$" idd.unidata.ucar.edu

Comments:

- I don't remember what the REQUEST line(s) look like in your
  LDM configuration file, but I am sure that it/they do not
  match the example above

  I know this because you were/are not getting all of the products
  available in CONDUIT, so your REQUEST line(s) must specify a
  subset.

- 'request' in a REQUEST line is case insensitive, so 'request' is
  the same thing as 'REQUEST'

Request:

- please send us your LDM configuration file (~ldm/etc/ldmd.conf) as an
  email attachment

  I will then fashion a CONDUIT REQUEST split that will hopefully help
  mitigate the problem you are experiencing.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: OYS-240819
Department: Support CONDUIT
Priority: Normal
Status: Closed
===================
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