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20201028: Re: [conduit] CONDUIT LDM Clock Drift

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  • Subject: 20201028: Re: [conduit] CONDUIT LDM Clock Drift
  • Date: Wed, 28 Oct 2020 11:20:04 -0600
Hi Bob and Daryl,

Both we and Pete Pokrandt (UWisconsin/AOS) have reported the clock
drift on the NCEP machines that are the source of the feed.  I,
in particular, have let them know that the drift has affected at
least a couple of sites that had configured their LDMs (via the
LDM registry) to minimize latency (meaning throw away any products
that have a latency greater than their configured amount).  We
were told in September that the clock drift problem was scheduled
to be fixed in October, and I misinterpreted this to mean that it
would be addressed in early October.

If you were not already aware, more than one NCEP person is subscribed
to the address@hidden email list.  Perhaps your postings
will help move addressing the problem up the list of things to do.

Cheers,

Tom

On 10/28/20 11:09 AM, Bob Lipschutz - NOAA Affiliate via conduit wrote:
We see the same here at NOAA/GSL. Here is our CONDUIT latency trace for the last 6 months. The drift started in early May. Prior to that, latency was flat and <10s. 

CONDUIT_latency_20201028.png


     Bob Lipschutz
     NOAA/ESRL/Global Systems Lab (formerly GSD)
     IT Services/Data Services Group
address@hidden <mailto:address@hidden>
On Wed, Oct 28, 2020 at 4:55 PM Herzmann, Daryl E [AGRON] <address@hidden <mailto:address@hidden>> wrote: 

    Greetings (emailing the right list this time!),

    It has been mentioned a few times on this list that there is a clock
    drift issue with the CONDUIT LDM feed emitting from NCO/IDP.  I'd
    like to ping this issue again and see if NCO can please check that
    system clocks are being synced there.  The attached plot of feed
    latency shows the building of latency with time from my monitoring,
    which is a tell tale sign of clock drift.

    thanks!
    daryl

    --
    /**
      * daryl herzmann
      * Systems Analyst III -- Iowa Environmental Mesonet
      * https://mesonet.agron.iastate.edu
      */
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