[gradsusr] NOMADS download speeds

[Wesley Ebisuzaki]

Joey,

       My impression of the nomads server is that it is very fast.  
However, I have a very fast link to the internet and
the site is only 10 miles away.

      You are using the GFS which has 0.5 degree resolution (260K 
points) and you are using the filter program
which can create a regional subset.   If you are asking for a 5x5 grid, 
then your download speeds will be
slow.  After all you have to process 10K points for every point sent to 
you. 

     Another possibility is that you may have run afoul of some 
fair-usage filter.   Every site needs some protection
against denial-of-service attacks and poorly programmed web scripts.  
Anyways the nomads help desk is a more
appropriate source of information than the GrADS user forum.

    Wesley Ebisuzaki


Joey Woodson wrote:
> Is there any way to speed up downloads from the NOMADS server 
> (http://nomads.ncep.noaa.gov/cgi-bin/filter_gfs_hd.pl)? I currently 
> run a site that spends around 6-8 seconds per forecast hour generating 
> maps. Having said that, it is quite frustrating to see download times 
> for 1 MB of GRIB data exceed 10 seconds at times. I currently use 4 
> wget sessions in parallel to handle the downloading, and I only sleep 
> for 2 seconds instead of 10 when polling the NOMADS server to check 
> when the next file is available, so as you can see I am very 
> speed-oriented. Is there any way to download faster, or is 
> partial-downloading (downloading part of the GRIB file, generating the 
> relevant maps for the first part while the rest downloads, then 
> generating the maps for the rest) the fastest way of doing this?
>
> Joey
> http://www.instantweathermaps.com <http://www.instantweathermaps.com/>
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