I am able to server local netCDF files from the current version of the
Thredds server. I have been struggling to get remote files working, so
my understanding may be flawed, but as far as I can tell, this is how
things work.
Thredds uses a "service" to work out how to fetch your data. Each data
set has a "service" which you specify by "name" which says how the data
should be fetched. You can have a "NetCDF" serviceType for NetCDF data,
or "DODS" for data fetched from a DODS server. The "base" for local
netCDF files should point to a directory on your filesystem, including
any trailing "/".
You need to :
* To specify the special service "this" as a DODS server (i.e. inform
the DODS server about itself, for the purposes of aggregating local data
sets later if need be)
* To specify a "service" for serving your local data, I called it
"local" in this example
* Specify any number of other named services
Datasets may be aggregated or not as you please. The following example
is a non-aggregated dataset. For non-aggregated datasets, you need to
specify the "internalService" property to tell Thredds the name of the
service you want to use for loading the data.
<!DOCTYPE catalog SYSTEM
"http://www.unidata.ucar.edu/projects/THREDDS/xml/AggServerCatalog.dtd";>
<catalog name="Test DODS Aggregation Server Catalog" version="0.6"
xmlns="http://www.unidata.ucar.edu/thredds";
xmlns:xlink="http://www.w3.org/1999/xlink";>
<dataset
name="Testing DODS Aggregation Server Catalog Top-level
dataset"
dataType="Grid" serviceName="this"
>
<service name="this" serviceType="DODS" base=""/>
<service name="local" serviceType="NetCDF"
base="file:///data/"/>
<property name="internalService" value="local"/>
<!-- -->
<dataset name="Data Sets">
<service name="DISK" serviceType="NetCDF"
base="file:///data/"/>
<property name="internalService" value="DISK"/>
<dataset name="Surface" urlPath="surface.nc"/>
</dataset>
</dataset>
</catalog>
I have also noticed that some of the XML tags have changed names from
the examples - for example "serviceType" instead of "service". This
doesn't appear to have been documented properly, but maybe I'm looking
in the wrong places.
Also, if anyone has had success loading "NetCDF" resources remotely,
please let me know! I'm trying to load
<dataset name="Home files foo">
<service name="HOME" serviceType="NetCDF"
base="http://tennesssee.id.au/"/>
<property name="service" value="HOME"/>
<dataset name="Foo" urlPath="surface.nc"/>
</dataset>
without success.
Cheers,
-Tennessee
Godin, Michael wrote:
I believe that Mike McCann is describing a bug in version 1.3 of the Thredds
server. I have xml that works fine in version 0.6, but which fails to serve
NetCDF files in version 1.3, even though the catalog.xml file passes the
validate test. Using the automatic translation utility does not help either.
Mike Godin
Yuan wrote:
McCann, Mike wrote:
-----Original Message-----
From: Yuan Ho [<mailto:yuanho@xxxxxxxxxxxxxxxx>]
Sent: Wednesday, October 27, 2004 9:29 AM
To: McCann, Mike
Cc: 'thredds@xxxxxxxxxxxxxxxx'
Subject: Re: Serving local netCDF files though DODS
McCann, Mike wrote:
Hello,
I am trying to serve local netCDF files through the agg
server and access
them through the DODS API. It is not working.
Have you installed a DODS server and link these netCDF
files to this server? According
to this configure file the serviceType is DODS, you
need a DODS server. AGG server is
based on DODS server, hope this will not confuse you.
Yuan
Hi Yuan,
I am running this on a Win2k laptop and am not aware of another
DODS
netCDF server for this platform. I was lead to believe that the
dodsC AS would perform the function of a DODS netCDF server.
Is this not true? How can I serve netCDF files through DODS from
my laptop?
This is important for taking this technology on the road for
presentations at workshops and conferences.
Regarding confusion, I admit that I am confused by the examples
presented at:
<http://my.unidata.ucar.edu/content/projects/THREDDS/tech/dodsAS/AggServerConfig.html>
Example 6 suggests that the AS can serve local netCDF files as
DODS data sets. (Replacing the "..." at the beginning of this
XML
snippet with actual tags would be helpful. Also, it'd be nice
to be more explicit about the differences between examples 3
and 6.)
-Mike
Ok, so what you need is a netCDF type service. I think your config is
ok, but you confused
the dataset name and urlpath, dataset name is only the one you want to
see on browser, and the
urlpath need to have the dataset real file name there.
Yuan
Here is the contents of my
dodsC/catalogConfig.xml file:
<!DOCTYPE catalog SYSTEM
"<http://www.unidata.ucar.edu/projects/THREDDS/xml/AggServerCat>
alog.dtd">
<catalog name="THREDDS - DODS Aggregation Server Catalog"
version="0.6" xmlns="<http://www.unidata.ucar.edu/thredds>;
xmlns:xlink="<http://www.w3.org/1999/xlink>;>
<dataset name="AUVCTD mission netCDF files"
serviceName="this">
<service name="this" serviceType="DODS"
base=""/>
<service name="local" serviceType="NetCDF"
base="file:///C:/iagdata/ssds/data/auvctd/missionnetcdfs/"/>
<dataset name="Non-Aggregated Netcdf Files"
dataType="Grid" serviceName="this">
<property name="internalService" value="local"/>
<dataset
name="2004/2004029/2004.029.03/parosci.nc"
urlPath="2004/2004029/2004.029.03/parosci.nc"/>
</dataset>
</dataset>
</catalog>
It validates and passes the debug test, yet when I click on
any of the DDS or DAS
links I get this in my browser:
kDODServlet ERROR:
dods.servlet.DODSServlet.getDataset(Ldods/servlet/ReqState;
Ldods/servlet/GuardedDataset;
I don't see any helpful messages in the log
files.
What am I doing wrong? Even some suggestions as to how I may do my own debugging
will be helpful.
-Mike
--
Mike McCann Software Engineer
Monterey Bay Aquarium Research Institute
7700 Sandholdt Road
Moss Landing, CA 95039-9644
Voice: (831) 775-1769 Fax: (831) 775-1646
<http://www.mbari.org/rd/iag.htm>
