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Hi Rich, I did the following, and verified that the added attribute shows up in the OpenDap form. Note that virtual datasets (the NcML makes this a virtual dataset) can't be served up via HTTP or FTP. <?xml version="1.0" encoding="UTF-8"?> <catalog name="THREDDS Server Default Catalog : You must change this to fit your server!" xmlns="http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0" xmlns:xlink="http://www.w3.org/1999/xlink"> <service name="all" base="" serviceType="compound"> <service name="odap" serviceType="OpenDAP" base="/thredds/dodsC/" /> <service name="ncdods" serviceType="OpenDAP" base="/thredds/dodsC/" /> <service name="http" serviceType="HTTPServer" base="/thredds/fileServer/" /> <!--service name="wcs" serviceType="WCS" base="/thredds/wcs/" /--> <!--service name="wms" serviceType="WMS" base="/thredds/wms/" /--> <!--service name="ncss" serviceType="NetcdfSubset" base="/thredds/ncss/grid/" /--> </service> <datasetRoot path="rsignell/noncacheddata" location="C:/Users/madry/work/RichSignell/" cache="false" /> <dataset name="Rich Signell Noncached Data" ID="noncached Data" urlPath="rsignell/virtualdata/ncml" dataType="Grid"> <serviceName>all</serviceName> <netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2" location="C:/Users/madry/work/RichSignell/5941mc-a.nc"> <attribute name="cdm_data_type" value="any"/> </netcdf> </dataset> </catalog> I'll see about answering on SO, too. -Lansing > For several years on our THREDDS Data Server (TDS) we've been happily > using the cache="false" functionality on datasetRoot to tell the TDS > not to cache several netcdf files. > > <service name="allServices" serviceType="Compound" base=""> > <service name="ncdods" serviceType="OpenDAP" base="/thredds/dodsC/"/> > <service name="HTTPServer" serviceType="HTTPServer" > base="/thredds/fileServer/"/> > <service name="iso" serviceType="ISO" base="/thredds/iso/"/> > <service name="uddc" serviceType="UDDC" base="/thredds/uddc/"/> > </service> > > <datasetRoot path="FVCOM" location="/http/www/CODFISH/Data/FVCOM/" > cache="false"/> > > <dataset name="NECOFS GOM2 Forecast" ID="gom2_nocache" > serviceName="allServices" > urlPath="FVCOM/NECOFS/Forecasts/NECOFS_GOM2_FORECAST.nc" dataType="Grid"/> > > The reason we don't want to ever cache these files is that every day > these daily forecast files get overwritten with files that have the > same name, but different data. > > But now we have a need to add and modify the attributes of these > datasets. In particular, we would like to add the global attribute > > <attribute name="cdm_data_type" value="any"/> > > Can we modify attributes via NcML when the dataset to be modified is > contained in this kind of datasetRoot construct? > > It would be great if the question could be answered here: > <http://stackoverflow.com/questions/19008223/possible-to-add-attributes-via-ncml-to-non-cached-thredds-datasets> > where the formatting is nice, and more folks can benefit/participate. > > Thanks, > Rich > > > -- > Dr. Richard P. Signell (508) 457-2229 > USGS, 384 Woods Hole Rd. > Woods Hole, MA 02543-1598 > > Ticket Details =================== Ticket ID: QWG-847709 Department: Support THREDDS Priority: Urgent Status: Open