Configuration Catalogs
The TDS is configured with XML files which are called configuration catalogs (they also can be referenced as server-side catalogs).
The configuration catalogs contain information detailing the datasets the TDS will serve and what services will be available for each dataset.
Location
The TDS configuration files are located in the thredds
subdirectory of the TDS Content Directory (tds.content.root.path
) specified in $JAVA_OPTS
setting for the JVM.
The TDS comes with the configuration files (note that not all of them contain the word ‘catalog’ in their name):
Name | Description |
---|---|
catalog.xml |
This is the main TDS client configuration file (a.k.a, the root catalog) used to serve data. [more information] |
enhancedCatalog.xml |
Example configuration catalog, demonstrating advanced features (referenced from catalog.xml ).[more information] |
threddsConfig.xml |
Main TDS configuration file for allowing non-default services, configuring caching, etc. [more information] |
wmsConfig.xml |
A configuration file for the THREDDS Web Mapping Service (WMS). [more information] |
Nomenclature
Before continuing, there is a problem with nomenclature that needs to be addressed:
Configuration Catalogs Versus Client Catalogs
Unfortunately, the term “catalog” is used for more than just TDS configuration files.
It can also be used to reference the HTML and XML displays the TDS produces for client consumption. These client catalogs display data and are accessible via HTTP and other protocols.
Example Of A Client Catalog
Here is an example of a client-side catalog generated by the TDS for GOES East Rebroadcast Satellite Data.
It is available in both HTML and XML format:
- https://thredds.ucar.edu/thredds/catalog/satellite/goes/east/grb/catalog.html
- https://thredds.ucar.edu/thredds/catalog/satellite/goes/east/grb/catalog.xml
Knowing The Difference Between The Two
The TDS configuration catalogs represent the top-level client catalogs served by the TDS. Specifically, the TDS takes the information in the configuration catalogs and uses it to generate the client catalogs. The configuration information in the catalog file is only needed by the server, and the client view of the catalogs do not contain any server specific configuration information.
It can be confusing to differentiate between the two uses of the term “catalog.” Therefore, in this documentation, we are careful to make the distinction between configuration catalogs and client catalogs.
When in doubt, think:
- Configuration catalog = server-side
- Client Catalog = client-side
How To Proceed With Configuration
THREDDS catalogs collect, organize, and describe accessible datasets. They provide a hierarchical structure for organizing the datasets as well as an access method (URL), and a human-understandable name for each dataset. Further descriptive information about each dataset can also be added.
Use the information in the Configuration section of this documentation, and reference the catalog specification to create your own catalogs.
A good place to start is to modify the existing catalogs for your own purposes.
You MUST use the root catalog.xml
and threddsConfig.xml
files.
The TDS consults these files on startup.
The enhancedCatalog.xml
and wmsConfig.xml
files are optional.