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Re: No WSI feed from wsihcsn.unidata.ucar.edu to iita at 99082610 (fwd)


===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================

---------- Forwarded message ----------
Date: Thu, 26 Aug 1999 09:48:14 -0600 (MDT)
From: David Himes <address@hidden>
To: address@hidden
    Steve A Drake <address@hidden>
Subject: Re: No WSI feed from wsihcsn.unidata.ucar.edu to iita at 99082610


Peter, others 
According to Peter Neilley:
> 
> Dave:
> 
>> What triggers these messages?  When the WSI data on disk looks more
>> than some number of minutes old?   Does it monitor the WSI stream
>> and detect when the products cease to com  in?  

> Celia can respond more precisely, but I believe its a product count
> per hour threshold that triggers the messages.  If the data is late
> (ie WSI data has > 1 hr latency) then the # of products in that hour
> can be very small or zero and this can trigger the messages.

That's close enough.  I was just curious on whether the data stream
had stopped or if the products were just late.


>> Also, how many radars are you guys processing on WSI?  I know you are
>> asking for all of the radars, but are you also filing them and doing
>> other processing directly on iita?
 
> By policy, iita does not do any data processing.  Not even filing at
> this point.  This was a change we instituted when we took it over.
> Eventually, we may make local copies of the raw datastreams to have a
> short term archive for distribution to sites that went down for short
> periods of time, but for now, iita is merely a data traffic cop.  I
> believe our sole responsibility and therefore sole authority with iita
> is to push data around UCAR/Universities.

I thought this was the case, but I did think that data was being filed,
especially after you had upgraded to  such a powerful machine. 

> All of our data processing is done with RAP-owned machines, including
> the WSI data.

> We currently file all 150 radars, and render about 40 of them in real
> time.  We might be able to render all 150 shortly.  The rendered data
> are made available via the web at
>    www.rap.ucar.edu/staff/pneilley/NIDS_table.html.

Peter, I've looked at this before and think it is a great set of web
pages.  What do you use to render/process the images?  Do you ever
have problems with the javascript based animator that your use for
looping the images?

>> Did you and Rob come to any other conclusion about the LDM latency
>> issue discovered with the newer ldm?

> This is getting annoying.  Its not even clear to me that SCD is aware
> of the problem.  Unidata believes the latency is due to SCD mods on the
> network in FL4.  But I'm not convinced.  WSI latency this very moment
> is small, but was 25 minutes when I started typing this note.

I was just wondering.  Maybe the latency is being propagated from the
source.  That is, the data is coming in from the satellite dish with
varied latency.  I talked to Mike Schmidt about this yesterday and as
far as anyone can tell, it is not an SCD problem right now.  There have
been several SCD problems over the past week that were major.
Yesterday for at least two hours in the morning, the NETS group had
router filters installed incorrectly that caused major problems for our
networks.

As far as I know, there is no problem occurring that can be called
"network" problems.

Thanks for getting back to me on this and let me know if you want or
need my help trying to narrow down the LDM/data latency problem.  I do
think that Robb and Celia will be able to figure it out, but that means
spending some time analyzing where things are failing.

Dave

> Peter Neilley, NCAR/RAP
> address@hidden
> 303-497-8446