One follow-up to this. Rich Signell discovered a workaround: if my TDS
catalog references a separate NcML file that contains the NcML aggregation,
it works. However, attempting to do the aggregation within the TDS catalog
still fails (seems to be a bug). Below are examples of what works (#1) and
what doesn't (#2). This is using TDS 4.3.16 - 20130319.1353.
1. This works; put the aggregation into a separate .ncml file (test.ncml):
<?xml version="1.0" encoding="UTF-8"?>
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<attribute name="title" value="HYCOM test: temp and salinity union"/>
<aggregation type="union">
<netcdf location="dods://
apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomT
"/>
<netcdf location="dods://
apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomS
"/>
</aggregation>
</netcdf>
Then reference this .ncml file inside the TDS catalog:
<?xml version="1.0" encoding="UTF-8" ?>
<catalog name="HYCOM Global Ocean Model"
xmlns="
http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0";
xmlns:xlink="http://www.w3.org/1999/xlink"; >
<service name="gridServices" serviceType="Compound" base="">
<service name="opendap" serviceType="OpenDAP"
base="/thredds/dodsC/" />
<service name="ncss" serviceType="NetcdfSubset"
base="/thredds/ncss/grid/" />
<service name="wms" serviceType="WMS"
base="/thredds/wms/" />
<service name="wcs" serviceType="WCS"
base="/thredds/wcs/" />
<service name="iso" serviceType="ISO"
base="/thredds/iso/" />
<service name="ncml" serviceType="NCML"
base="/thredds/ncml/" />
</service>
<dataset name="HYCOM Global Ocean Model"
ID="hycom_global"
urlPath="hycom_global">
<metadata inherited="true">
<serviceName>gridServices</serviceName>
<dataType>Grid</dataType>
</metadata>
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";
location="file:/usr/local/tomcat-tdsdev/content/thredds/idd/test.ncml"/>
</dataset>
</catalog>
2. This doesn't work: trying to do the NcML aggregation inside the TDS
catalog:
<?xml version="1.0" encoding="UTF-8" ?>
<catalog name="HYCOM Global Ocean Model"
xmlns="
http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0";
xmlns:xlink="http://www.w3.org/1999/xlink"; >
<service name="gridServices" serviceType="Compound" base="">
<service name="opendap" serviceType="OpenDAP"
base="/thredds/dodsC/" />
<service name="ncss" serviceType="NetcdfSubset"
base="/thredds/ncss/grid/" />
<service name="wms" serviceType="WMS"
base="/thredds/wms/" />
<service name="wcs" serviceType="WCS"
base="/thredds/wcs/" />
<service name="iso" serviceType="ISO"
base="/thredds/iso/" />
<service name="ncml" serviceType="NCML"
base="/thredds/ncml/" />
</service>
<dataset name="HYCOM Global Ocean Model"
ID="hycom_global"
urlPath="hycom_global">
<metadata inherited="true">
<serviceName>gridServices</serviceName>
<dataType>Grid</dataType>
</metadata>
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
<attribute name="title" value="HYCOM test: temp and salinity union"/>
<aggregation type="union">
<netcdf location="dods://
apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomT
"/>
<netcdf location="dods://
apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomS
"/>
</aggregation>
</netcdf>
</dataset>
</catalog>
On Fri, Apr 19, 2013 at 10:35 AM, John Maurer <jmaurer@xxxxxxxxxx> wrote:
> Hi all,
> I'm attempting to do an NcML "union" aggregation of several variables from
> a forecast model that are contained in separate remote OPeNDAP locations.
> While this works in TDS 4.2 (and Tools UI 4.2), I'm getting an error in TDS
> 4.3.16 (and Tools UI 4.3). Below are the details. Perhaps this is related
> to the recent "joinExisting" remote aggregation problem that Roland
> Schweitzer reported in TDS 4.3 here:
> https://www.unidata.ucar.edu/mailing_lists/archives/thredds/2013/msg00093.html.
> I have already tried clearing the cache and restarting Tomcat as was
> suggested in that chain: also did not solve the problem in my case, either.
> Thanks in advance for your help on this.
> Cheers,
> John Maurer
> Pacific Islands Ocean Observing System (PacIOOS)
> University of Hawaii at Manoa
>
> TDS catalog:
>
> <?xml version="1.0" encoding="UTF-8" ?>
>
> <catalog name="HYCOM Global Ocean Model"
> xmlns="
> http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0";
> xmlns:xlink="http://www.w3.org/1999/xlink"; >
>
> <service name="gridServices" serviceType="Compound" base="">
> <service name="opendap" serviceType="OpenDAP"
> base="/thredds/dodsC/" />
> <service name="ncss" serviceType="NetcdfSubset"
> base="/thredds/ncss/grid/" />
> <service name="wms" serviceType="WMS"
> base="/thredds/wms/" />
> <service name="wcs" serviceType="WCS"
> base="/thredds/wcs/" />
> <service name="iso" serviceType="ISO"
> base="/thredds/iso/" />
> <service name="ncml" serviceType="NCML"
> base="/thredds/ncml/" />
> </service>
>
> <dataset name="HYCOM Global Ocean Model"
> ID="hycom_global"
> urlPath="hycom_global">
>
> <metadata inherited="true">
> <serviceName>gridServices</
> serviceName>
> <dataType>Grid</dataType>
> </metadata>
>
> <netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2
> ">
> <attribute name="title" value="HYCOM test: temp and salinity union"/>
>
> <aggregation type="union">
> <netcdf location="dods://
> apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomT
> "/>
> <netcdf location="dods://
> apdrc.soest.hawaii.edu:80/dods/public_data/Model_output/HYCOM/global/hycomS
> "/>
> </aggregation>
> </netcdf>
>
> </dataset>
>
> </catalog>
>
>
> threddsServlet.log:
>
> 2013-04-19T09:29:09.165 -1000 [ 1119756][ 8] INFO -
> threddsServlet - Remote host: 128.171.151.240 - Request: "GET
> /thredds-test/dodsC/hycom_
> global_temp.html HTTP/1.1"
> 2013-04-19T09:29:09.328 -1000 [ 1119919][ 8] ERROR -
> thredds.server.opendap.OpendapServlet - path= /hycom_global_temp.html
> java.lang.NullPointerException
> at ucar.nc2.util.URLnaming.resolveFile(URLnaming.java:238)
> at ucar.nc2.ncml.NcMLReader.readAgg(NcMLReader.java:1348)
> at ucar.nc2.ncml.NcMLReader.readNetcdf(NcMLReader.java:491)
> at ucar.nc2.ncml.NcMLReader.readNcML(NcMLReader.java:438)
> at ucar.nc2.ncml.NcMLReader.readNcML(NcMLReader.java:351)
> at
> thredds.servlet.DatasetHandler$NcmlFileFactory.open(DatasetHandler.java:261)
> at
> thredds.servlet.DatasetHandler$NcmlFileFactory.open(DatasetHandler.java:252)
> at ucar.nc2.util.cache.FileCache.acquire(FileCache.java:224)
> at
> ucar.nc2.dataset.NetcdfDataset.openOrAcquireFile(NetcdfDataset.java:685)
> at
> ucar.nc2.dataset.NetcdfDataset.acquireFile(NetcdfDataset.java:622)
> at
> thredds.servlet.DatasetHandler.getNetcdfFile(DatasetHandler.java:158)
> at
> thredds.server.opendap.OpendapServlet.getDataset(OpendapServlet.java:913)
> at
> thredds.server.opendap.OpendapServlet.doGetHTML(OpendapServlet.java:613)
> at
> thredds.server.opendap.OpendapServlet.doGet(OpendapServlet.java:230)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
> at
> thredds.servlet.filter.CookieFilter.doFilter(CookieFilter.java:54)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
> at
> thredds.servlet.filter.RequestQueryFilter.doFilter(RequestQueryFilter.java:120)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
> at
> thredds.servlet.filter.RequestPathFilter.doFilter(RequestPathFilter.java:102)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
> at
> thredds.server.RequestBracketingLogMessageFilter.doFilter(RequestBracketingLogMessageFilter.java:48)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
> at
> org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
> at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
> at
> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
> at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
> at
> org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
> at
> org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
> at
> org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
> at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown
> Source)
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown
> Source)
> at java.lang.Thread.run(Unknown Source)
> 2013-04-19T09:29:09.331 -1000 [ 1119922][ 8] INFO -
> threddsServlet - Request Completed - 500 - -1 - 166
>
>
