Hi,
Richard Signell wrote:
I'm pretty sure the caching behavior has changed a lot with different
versions of the THREDDS Data Server -- and I'm pretty sure the latest
4.1 server does not rescan the entire aggregation.
What version are you using?
TDS 4.1 built on October 10th. I'm not positive that it's rescanning the
entire directory but it definitely takes longer (10-60 seconds versus ~1
second) just after I touch a file in the directory. This current test
was using recheckEvery="-1" but the results are the same without
recheckEvery and with it set to a normal value like "15 min".
As long as nothing in the directory has a new date, I can access the
dataset in ~1 second even hours later.
Dave
-Rich
On Fri, Oct 23, 2009 at 12:27 PM, David Robertson
<robertson@xxxxxxxxxxxxxxxxxx> wrote:
Hi all,
It seems that THREDDS forces a rescan if the time stamp on the directory has
changed. Even if I set recheckEvery to -1 or 90 days it still appears to
rescan when the modified date on the folder changes. I tested this using a
simple "touch junk" command in the directory I'm aggregating.
This makes sense so that files added to the directory can be added to the
aggregation. However, is there a way to tell TDS to skip this step for a
given dataset or will I need to put my non-changing datasets in subfolders?
If I put them in subfolders will I be able to aggregate the entire dataset
together anymore? Perhaps something like:
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<aggregation dimName="time" type="joinExisting">
<scan location="/home/om/dods-data/thredds/cool/avhrr/nc4/2006/"
regExp="^2006.*\.nc" />
</aggregation>
</netcdf>
for each year and
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<aggregation dimName="time" type="joinExisting">
<scan location="/home/om/dods-data/thredds/cool/avhrr/nc4/"
regExp=".*/*\.nc" />
</aggregation>
</netcdf>
to get the aggregation to go through the subfolders and put the years
together?
The solution of getting TDS to skip rescan on specific datasets would be
preferable to simplify scripts and avoid having to change them each new
year.
Thanks,
Dave
Roy Mendelssohn wrote:
I believe if you don't set rescan it uses the default value - but would
have to check on that. I know there is a way to tell it to not rescan.
-Roy
On Oct 22, 2009, at 9:42 AM, David Robertson wrote:
Hi,
Roy Mendelssohn wrote:
What is your rescan set to for that dataset? That is probably what is
causing it.
I am not using rescan or recheckEvery so that's probably the problem the
dataset element I'm using is pasted below:
<dataset name="2006"
ID="cool-avhrr-bigbight-2006"
urlPath="cool/avhrr/bigbight/2006" >
<metadata inherited="true">
<timeCoverage>
<start>2006-01-01 03:10:00 UTC</start>
<end>2006-12-31 22:53:00 UTC</end>
</timeCoverage>
<geospatialCoverage>
<northsouth>
<start>34.9950981140137</start>
<size> 11.0090637207031</size>
<units>degrees_north</units>
</northsouth>
<eastwest>
<start>-77.0059967041016</start>
<size> 14.0119972229004</size>
<units>degrees_east</units>
</eastwest>
</geospatialCoverage>
</metadata>
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<aggregation dimName="time" type="joinExisting">
<scan location="/home/om/dods-data/thredds/cool/avhrr/nc4/"
regExp="^2006.*\.nc" />
</aggregation>
</netcdf>
</dataset><!--2006-->
On Oct 22, 2009, at 8:47 AM, David Robertson wrote:
Hi,
Is there a way to tell the TDS NOT to look for new files to add to an
aggregated dataset? I have several aggregations set up that do not change
(no added or removed or modified files). Yesterday after generating the
aggregation cache, access the dataset was quite quick; ~1 second to load the
Data Access Form. However, when I try to access those same datasets today it
takes just as long as it did to generate the aggregation cache in the first
place (5 minutes).
It should be noted that these aggregations are subsets of files in a
directory that IS being updated. What I have done used a regExp to separate
a very large dataset into years. The 2008 and prior aggregations will not
have files added so I'm looking for a way to stop the TDS from searching for
new files to add to the aggregation cache.
Thanks,
Dave
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**********************
"The contents of this message do not reflect any position of the U.S.
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097
e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/
"Old age and treachery will overcome youth and skill."
"From those who have been given much, much will be expected"
**********************
"The contents of this message do not reflect any position of the U.S.
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097
e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/
"Old age and treachery will overcome youth and skill."
"From those who have been given much, much will be expected"
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