The National Virtual Observatory (NVO) Extensible Secure Scalable Service Infrastructure (NESSSI) is a Web service architecture and software framework (see figure) that enables Web-based astronomical data publishing and processing on grid computers such as the National Science Foundation's TeraGrid. Characteristics of this architecture include the following:

  • Services are created, managed, and upgraded by their developers, who are trusted users of computing platforms on which the services are deployed.
  • Service jobs can be initiated by means of Java or Python client programs run on a command line or with Web portals.
  • Access is granted within a graduated security scheme in which the size of a job that can be initiated depends on the level of authentication of the user.
In this Model, the application server is Web-service container that accepts HTTP connections that maybe SOAP messages and may have a certificate attached.

A "small" service request may be submitted anonymously. A "medium" request may be submitted with a "weak" certificate issued by the NVO or another certificate authority not associated with an official grid computing organization like TeraGrid or the Department of Energy (DOE). A "large" request must be accompanied by a "strong" certificate issued by the TeraGrid or DOE certificate authority. User certificates are managed by the Clarens Grid-Enabled Web Services Framework (clarens.sourceforge.net ).

This work was done by Joseph Jacob, Craig Miller, Roy Williams, Conrad Steenberg, and Matthew Graham of Caltech for NASA's Jet Propulsion Laboratory.

This software is available for commercial licensing. Please contact Karina Edmonds of the California Institute of Technology at (626) 395-2322. Refer to NPO-45067.



This Brief includes a Technical Support Package (TSP).
Document cover
Service-Oriented Architecture for NVO and Teragrid Computing

(reference NPO-45067) is currently available for download from the TSP library.

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