This is the OPeNDAP 4 Data Server, also known as Hyrax.
Hyrax is a new data server which combines the efforts at UCAR/HAO to build a high performance DAP-compliant data server for the Earth System Grid II project with existing software developed by OPeNDAP.
Hyrax uses the Java servlet mechanism to hand off requests from a general web daemon to DAP format-specific software. This results in higher performance for small requests. The servlet front end, which we call the OPeNDAP Lightweight Front end Server (OLFS) looks at each request and formulates a query to a second server (which may or may not on the same machine as the OLFS) called the Back End Server (BES).
The BES is the high-performance server software from HAO. It handles reading data from the data stores and returning DAP-compliant responses to the OLFS. In turn, the OLFS may pass these response back to the requestor with little or no modification or it may use them to build more complex responses. The nature of the Inter Process Communication (IPC) between the OLFS and BES is such that they should both be on the same machine or be able to communicate over a very high bandwidth channel.
Both the OLFS and the BES will run and serve test data immediately after a default installation. Additional configuration is required for them to serve site specific data.
- THREDDS Catalog Support
- Hyrax supports the THREDDS catalogs. It can serve user supplied static catalogs and it will dynamically generate THREDDS catalogs of it's internal holdings.
- Dataset Aggregation
- Collections of related data resources can be collected into a single dataset using the aggregation features. Typically these are formed for geographic tiles, time series, etc.
- Adding/modifying dataset content.
- Datasets can be modified by there server without having to actually change the underlying files. These views are independently accessible from the original data. Both dataset metadata and data values may be added or changed.
- Supports multiple source data formats
- Server can ingest source data stored as HDF4, HDF4-EOS, HDF5, HDF5-EOS, NetCDF-3, NetCDF-4, CEDAR, FITS, Comma Separated Values, and raw ASCII and Binary formats. Because of Hyrax's extensible design, it's easy to add new source data formats.
- Supports data retrieval in multiple return formats
- Hyrax is able to return data in DAP, NetCDF-3, and ASCII formats, Or, you can add your own response types.
- Hyrax supports a gateway feature that allows it to provide DAP (and other Hyrax) services for remotely held datasets that are stored in any of Hyrax's source data formats.
- Hyrax provides RDF descriptions of it's data holdings. These can enable semantic web tools to operate upon the metadata content held in the server.
- Server side functions
- Hyrax supports a number of server side functions out of the box including:
- geogrid: Subset applicable DAP Grids using latitude and longitude values.
- grid: Subset any DAP Grid object using the values of it's map vectors.
- linear_scale: Apply a linear equation to the data returned, including automatic use of CF attributes.
- version: The version function provides a list of the server-side processing functions available.
- New ones are easy to add.
- Extensible WebStart functionality for data clients
- Hyrax provides WebStart functionality for a number of Java based DAP clients. It's simple to add new clients to the list that Hyrax supports.
- Extensible/Configurable web interface
- The web interface for both Hyrax and the administrator's interface can be customized using CSS and XSL. You can add your organizations logo and specialize the colors and fonts in the presentation of data sets.
- Administrator's interface
- Control and dynamically update Hyrax from a convenient web interface. See the Admin interface documentation.
- SOAP Messaging Support
- Hyrax supports SOAP requests.
- Feature Request
- Is there a feature you would like to see but don't? Let us know: firstname.lastname@example.org or email@example.com (You need to subscribe first)
To obtain Hyrax just go to the Hyrax download page and get it.
- Hyrax Installation Instructions
- Hyrax - Administrators Interface
- Hyrax Configuration Instructions
- Hyrax integration with the Apache Web Server
- Customizing Hyrax
- Release Notes
- System Administrators Workshop
- NetCDF data handler
- HDF4 data handler
- HDF5 data handler
- FreeForm data handler
- NetCDF File Response handler
- NcML data handler
- Gateway handler (Interoperability between Hyrax and other web services)
- Eclipse - How to Setup Eclipse in a Shrew Checkout
- Hyrax - Build the Shrew Project
- Building the BES from source.
- How to debug the BES
- BES - Debugging Using besstandalone
- How to create your own BES Module
- Starting and stopping the BES
- Running the BES command line client
- BES Client commands
- BES XML Commands
- Extending your BES Module
- Example BES Modules - the Hello World example and the CSV data handler
- BES communication protocol using PPT (point to point transport)
- BES Administrative Commands
We hope we hope you find this software useful, and we welcome your questions and comments.
Hyrax Java Development:
- ndp <at> opendap <dot> org
Hyrax C++ Development:
- pwest <at> ucar <dot> edu (bes)
- jgallagher <at> opendap <dot> org (libdap)
OPeNDAP Hyrax development is sponsored by:
This material is based upon work supported by the National Science Foundation under Grant No. 0430822. Any opinions, findings and conclusions or recomendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).