I, that is NCDC, will not send out Dual Pol except as an archive after
the fact. I was just pointing out Dual Pol is much larger and we can
expect somewhere in the range of 20Mbits/second. I am not willing to
say when this will take place, the NWS will keep us informed. Keep in
mind that just because a site might be Dual Pol capable does not mean
they will be using that mode. I think we will see a gradual deployment
and then a gradual ramp up.
Back to the problem at hand. Many factors could play a role in this
problem, one of which I suspect is the summer load on the existing
network. Summer does present a larger volume just because it is summer
with all the "convectiveness" going on! With that in mind, are all of
the servers in the network, including the NWS Regional servers,
configured with a large enough queue to handle the increased load. If
just one server somewhere in the mix is configured too low, it could
cause dropped data, and I have seen this in summers past, but probably
not duplicate data.
Alan.
Gilbert Sebenste said the following on 7/9/2009 11:42 AM:
On Thu, 9 Jul 2009, Alan.Hall wrote:
Generally a larger volume of data and too small of a queue. I'm
assuming a sustained rate of 6-10Mbits for the NEXRAD II feed, that
means to keep an hours worth of data in the queue would take a queue
size of 2.7GBytes to 4.5GBytes. Of course you don't have to have an
hours worth of data in the queue as long as the pqact can process the
data in the queue before they drop out of the queue. By processing I
mean to pass it down stream and pqact. You can multi-stream the
pqacts and gain some performance. When Dual Pol comes around you'll
need a 9 GByte queue and then the AVSET might add another 20% onto
that. Alan.
Hello Alan,
Thanks for replying! I understand what youa re saying, but why has
this become a problem just now, long after the super-res transition?
When Dual Pol comes around you'll need a 9 GByte queue and then the
AVSET might add another 20% onto that.
This is interesting. Are you saying that you have the capability and
are planning to send out dual-pol? I just found out KLOT will be done
in September '10, if all goes perfectly well (wink!). If you are, I
need to start planning now for that. I have heard that bandwidth was a
major issue
and that it wouldn't be done right away.
*******************************************************************************
Gilbert Sebenste
********
(My opinions only!)
******
Staff Meteorologist, Northern Illinois University
****
E-mail:
sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://weather.admin.niu.edu **
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