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thanks dan, i can use the one that russ generated and save 3 hours of download time. On 10/11/2012 7:56 AM, Dan Swank wrote: > New Client Reply: nccopy advice - rechunking very large files > > John, > All files may be accessed here: > http://nomads.ncdc.noaa.gov/data/offlinestage/custom/narr-physaggs/ > Same directory Russ got it from. > narr-TMP-850mb* > are our first test case for which all variants are in place. > > -Dan > > > On Wed, Oct 10, 2012 at 6:37 PM, Unidata THREDDS Support > <address@hidden> wrote: >> Hi Mike: >> >> If you can make one of those file available on ftp or something, ill be able >> to profile the ncss. thanks! >> >> John >> >>> My use of "points" in my e-mail description might be misleading. I am >>> really meaning timeseries for individual grid cells from a gridded dataset. >>> >>> Thanks, >>> >>> Mike >>> >>> -- >>> D. Michael Grogan >>> ----------------------------------------- >>> STG, Inc. - Government ContractorData Access & Applications Branch >>> Climate Services and Monitoring Division >>> National Climatic Data address@hidden >>> Phone: (828) 271-4680 >>> >>> >>> >>> On Wed, Oct 10, 2012 at 5:23 PM, Mike Grogan <address@hidden> wrote: >>> >>>> THREDDS Support, >>>> >>>> We have been experimenting with different chunking schemes to support fast >>>> timeseries access for points within a large (~34 year) physical >>>> aggregation. Please reference Dan Swank's recent discussions with Russ Rew >>>> under ticket [netCDF #TSI-527912] in netCDF e-mail support. >>>> >>>> Dan has created a .nc4 version of this physical aggregation with chunk >>>> sizes time/98128,x/8,y/6. >>>> >>>> When we use the OPeNDAP interface in TDS, we are able to retrieve the >>>> entire ~ 34-year timeseries for a single x/y coordinate point in < 1/10th >>>> of a second when hitting TDS from localhost. >>>> >>>> However, when we use the NetCDF Subset Service (NCSS) in TDS to retrieve >>>> even just a one-month timeseries for a single lat/lon coordinate it takes >>>> 40 seconds or more. >>>> >>>> What is going on under the hood here with NCSS that would cause this >>>> discrepancy? I know the nearest x/y has to be found in coordinate space >>>> for the specified lat/lon. Is this calculation happening for each timestep >>>> for some reason? Something else? >>>> >>>> We are using the tds-4.3.13-20120807.191518-1.war that Marcos built for >>>> us a couple of months back. >>>> >>>> Sample URLs [unfortunately not public] are: >>>> >>>> >>>> http://SERVER_NAME:8080/thredds/dodsC/NARRphysagg33/narr-TMP-850mb_221_yyyymmdd_hh00_000.grb.grb2.nc4.ts.d0.ascii?TMP_850mb[0:1:98127][40][240] >>>> >>>> >>>> http://SERVER_NAME:8080/thredds/ncss/grid/NARRphysagg33/narr-TMP-850mb_221_yyyymmdd_hh00_000.grb.grb2.nc4.ts.d0?var=TMP_850mb&latitude=45&longitude=-83&time_start=1979-01-01T00%3A00%3A00.000Z&time_end=1979-01-31T21%3A00%3A00.000Z&vertCoord=&accept=csv >>>> >>>> Ignore the .grb and .grb2 parts of the filenames. These ARE NC4 files. >>>> The grb and grb2 are just in there showing our original conversion path >>>> in >>>> our experiments. >>>> >>>> Our d0 files are no compression. >>>> >>>> Thanks, >>>> >>>> Mike Grogan >>>> >>>> >>>> >>>> -- >>>> >>>> D. Michael Grogan >>>> ----------------------------------------- >>>> STG, Inc. - Government ContractorData Access & Applications Branch >>>> Climate Services and Monitoring Division >>>> National Climatic Data address@hidden >>>> Phone: (828) 271-4680 >>>> >>>> >>> >>> >> >> >> Ticket Details >> =================== >> Ticket ID: TSI-527912 >> Department: Support THREDDS >> Priority: Normal >> Status: Open >> > > > Ticket Details =================== Ticket ID: TSI-527912 Department: Support THREDDS Priority: Normal Status: Open