OPeNDAP Workshop 2016 — Emphasizing Advances for EOSDIS


During the upcoming Summer 2016 meeting of the ESIP Federation (July 19-22), OpenDAP will hold a Developers and Users Workshop. While many topics will be covered, a focus is to capitalize on recent EOSDIS-sponsored advances in Hyrax, OPeNDAP’s own software for server-side realization of the DAP2 and DAP4 protocols. These Hyrax advances are as important to data users as data providers, and the workshop will include hands-on experiences of value to both. Specifically, a balanced set of presentations and hands-on tutorials will address advances in

  1. server installation,
  2. server configuration,
  3. Hyrax “aggregation” capabilities,
  4. support for data-access from clients that are HTTP-based, JSON-based or OGC-compliant (especially WCS and WMS),
  5. support for DAP4,
  6. use and extension of server-side computational capabilities, and
  7. several performance-affecting matters.

Topics 2 through 7 will be relevant to data consumers, to data providers and—notably, because all OPeNDAP software is open source—to developers interested in extending Hyrax, building compatible clients, or employing Hyrax as middleware that enables interoperability across a variety of end-user and source-data contexts. A session for contributed talks will elaborate or augment the listed topics.

Please plan to attend and to share your own OPeNDAP-related work, whether emphasizing clients, servers or DAP-based middleware. Previous workshops have engendered many interesting ideas, and the most recent one (ESIP Summer Meeting of 2014) yielded participant requests for this year’s reprise. Submit ideas for sessions or abstracts for presentations to [email protected] by May 31st, 2016.


1.    Aggregation
    a.    combining discrete granules into a "virtual" object
    b.    "regular" = on a regular grid (all granules must share the same grid - size, dimensions, etc.)
    c.    "Back-End Server" (BES) Aggregation
    d.    using ncML
    e.    "On the Fly" (User-Driven) Aggregation
    f.    user search returns list of granules that want aggreated, including swath
    g.    Allow aggregation service accept DAP URLs, not just file path/names?
    h.    Build up responses and steam them back to user

2.    Authentication
    a.    Auth is coming... The things that will break are clients
    b.    Auth is typically implemented using Apache HTTPD and some third-party modules
    c.    Simple layered services - ncWMS2 won't work (likely) in an environment that requires authentication because ncWMS2 does not know how to authenticate. There's a likely work-around using the localhost IP address ( Adding Godiva - which is a WMS client that runs in a web browser - breaks this layered services model. The fix is to modify Godiva to support OAuth2        
    (and/or HTTP auth and redirects).

Gallagher, J.; Fulker, D.; OPeNDAP Workshop 2016 — Emphasizing Advances for EOSDIS; 2016 ESIP Summer Meeting. ESIP Commons , March 2016