[THREDDS #QWG-847709]: Possible to add attributes via NcML to non-cached THREDDS datasets?

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