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[IDD #GOK-818269]: Help -- NEXRAD3 feed no longer working, along with some GOES imagery from UNIWISC



Hi Gary,

Here are some numbers from the real-time statistics that Marcus' machine
is sending back to Unidata:

current data ingestion on gwoemul.wiu.edu:

Data Volume Summary for gwoemul.wiu.edu

Maximum hourly volume    481.502 M bytes/hour
Average hourly volume    247.684 M bytes/hour

Average products per hour      47720 prods/hour

Feed                           Average             Maximum     Products
                     (M byte/hour)            (M byte/hour)   number/hour
HDS                     179.680    [ 72.544%]      391.790    12378.295
IDS|DDPLUS               40.204    [ 16.232%]       55.577    35288.318
UNIWISC                  22.617    [  9.131%]       29.568       26.659
DIFAX                     3.360    [  1.356%]       12.090        4.841
FSL2                      1.823    [  0.736%]        2.076       22.227

Comparison of all of the data that a site like Marcus' could request given
sufficient bandwidth:

Data Volume Summary for idd.unidata.ucar.edu

Maximum hourly volume  14155.751 M bytes/hour
Average hourly volume   6973.663 M bytes/hour

Average products per hour     249825 prods/hour

Feed                           Average             Maximum     Products
                     (M byte/hour)            (M byte/hour)   number/hour
CONDUIT                2471.870    [ 35.446%]     7245.773    64061.738
NEXRAD2                2175.907    [ 31.202%]     2917.550    62035.357
NEXRAD3                 820.510    [ 11.766%]     1048.914    51436.000
NGRID                   690.929    [  9.908%]     1406.051    15980.810
HDS                     253.852    [  3.640%]      393.416    17838.524
FNMOC                   226.990    [  3.255%]     1312.805     1960.190
NIMAGE                  134.981    [  1.936%]      241.821      168.571
FNEXRAD                  87.758    [  1.258%]      109.766       72.405
IDS|DDPLUS               40.365    [  0.579%]       55.577    35461.214
EXP                      37.829    [  0.542%]       65.342      330.786
UNIWISC                  22.599    [  0.324%]       29.568       26.786
DIFAX                     3.305    [  0.047%]       12.090        4.833
GEM                       2.807    [  0.040%]       26.388      192.476
LIGHTNING                 2.129    [  0.031%]        4.094      232.762
FSL2                      1.830    [  0.026%]        2.076       22.357


A careful examination of both listing above show a couple of key features:

1) Marcus is requesting a small fraction of the data that is available

2) even with the current data request, not all of the data being
   requested is getting through

One of the key things we look at is a comparison of delivery latency
for two different streams of data, one of relatively low volume, and
one of a relative medium to high bandwidth:

IDS|DDPLUS receipt latencies on gwoeuml.wiu.edu (relatively low volume):

http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_nc?IDS|DDPLUS+gwoemul.wiu.edu

HDS receipt latencies on gwoemul.wiu.edu (relative moderate to high volume):

http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_nc?HDS+gwoemul.wiu.edu

I want to draw attention to the latencies seen at ~18Z each day:

- the latencies for the low volume feed are acceptable
- the latencies for the moderate volume feed are large enough that
  data disappears from the upstream feed machine before it can
  be sent to gwoemul

These two observations taken together are a classic signature of artificial
bandwidth limiting by packet shaping.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: GOK-818269
Department: Support IDD
Priority: Normal
Status: Closed


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