Re: [thredds] THREDDS Cache

• To: jerry y pan <jerry.ypan@xxxxxxxxx>
• Subject: Re: [thredds] THREDDS Cache
• From: Rich Signell <rsignell@xxxxxxxx>
• Date: Mon, 2 May 2011 16:59:31 -0400

Oops.  Typing too fast:  I meant
"  If they want NetCDF3 files they can use the NetCDF subset service
or use tools like NCO that can read opendap and
   generate NetCDF3..."

On Mon, May 2, 2011 at 4:57 PM, Rich Signell <rsignell@xxxxxxxx> wrote:
> Jerry,
>
> You might also check into using NetCDF4 files with deflation instead
> of .nc.gz.  Your users can still download as opendap or any of the
> other services.  If they want netcdf4 files they can use the NetCDF
> subset service or use tools like NCO that can read opendap and
> generate NetCDF 3 files.   You can convert NetCDF3 to NetCDF4 using
> level 1 deflation using NCO  (  ncks -4 -L 1 netcdf3.nc   netcdf4.nc).
>  They should be about the same size as the nc.gz files, and will be
> much faster to read since you don't have to uncompress the whole file.
>
> -Rich
>
>
> On Mon, May 2, 2011 at 2:27 PM, jerry y pan <jerry.ypan@xxxxxxxxx> wrote:
>> Hi John,
>> Our TDS (4.2) uses some compressed netcdf files (*.nc.gz) and it works fine,
>> except that the very first access to them were slow (relatively large files,
>> about 400 MB each). The subsequent accesses would be much faster, but it
>> would become slow again after a while of non-activity. I can see that TDS
>> uncompress these files to the temp data location, my question is that if TDS
>> cleans up these temp files, which leads to the work to decompress them next
>> time and hence the subsequent slowness? If so, is there a way to keep the
>> cache there permanently? Or, perhaps the faster response right after the
>> first access is due to in memory cache? Any configuration I could twist the
>> cache?
>>
>>
>> Thanks,
>> -Jerry Pan
>>
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>
>
>
> --
> Dr. Richard P. Signell   (508) 457-2229
> USGS, 384 Woods Hole Rd.
> Woods Hole, MA 02543-1598
>



-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598

• Follow-Ups:
  • Re: [thredds] THREDDS Cache
    • From: Russ Rew

• References:
  • [thredds] THREDDS Cache
    • From: jerry y pan
  • Re: [thredds] THREDDS Cache
    • From: Rich Signell