Hyrax - THREDDS Configuration
Hyrax now uses its own implementation of the THREDDS catalog services and supports most of the THREDDS catalog service stack. The implementation relies on two DispatchHandlers in the OLFS and utilizes XSLT to provide HTML versions (presentation views) for human consumption.
- Dynamic THREDDS catalogs for holdings provided by the BES are provided by the opendap.bes.BESThreddsDispatchHandler.
- Static THREDDS catalogs are provided by the opendap.threddsHandler.Dispatch
The default (olfs.xml) file now contains both of these handlers in the correct order/location for Hyrax operations.
Static THREDDS catalogs are "rooted" in a master catalog file, catalog.xml, located in the (persistent) content directory for the OLFS (Typically $CATALINA_HOME/content/opendap). The default catalog.xml that comes with Hyrax contains a simple catalogRef element that points to the dynamic THREDDS catalogs generated from the BES holdings. Additional catalog components may be added to the catalog.xml file to build (potentially large) static catalogs. Existing THREDDS catalogs should work with this new implementation.
- Since the BESThreddsDispatchHandler provides catalogs for the BES holdings, the static catalogs do not support the THREDDS datasetScan element, other than to provide links in the presentation view.
- The BES catalogs do not support a mechanism for including inherited metadata down the catalog tree (normally this functionality comes from the datasetScan element in a static catalog). If the need for this arises it can be done, just let us know!
Rather than provide an exhaustive explanation of the THREDDS catalog functionality and configuration I will appeal to the existing documents provided by our fine colleagues at UNIDATA:
Did you read all that? Excellent!
- The current default (olfs.xml) file comes with THREDDS configured correctly.
- The THREDDS master catalog is stored in the file $CATALINA_HOME/content/opendap/catalog.xml it can be edited to provide additional static catalog access.