GOST: Global Operating System Technologies

University of Southern California
Information Sciences Institute

Faculty and Staff

Former Faculty and Staff

Students graduated with the Ph.D.

Former Students

Project Goals

The Global Operating Systems Technologies project has been developing and deploying infrastructure supporting access to, and management of, information and resources on the Internet. The base information storage and access protocols used by the infrastructure impose minimal semantic interpretation on data making the underlying protocols, and the middleware services layered on top of the protocols, usable by a wide range of higher level applications.

Technical Approach and Project Innovations

As part of the GOST project's development of directory and file services, support has been built-in for (a) "transitive" indexing, (b) cooperative, secure, and flexible caching, (c) garbage collection, and (c) multi-mechanism replication. These functions are layered above, and are available to applications which use the Prospero Directory Service (PDS).

Transitive indexing allows users and applications to locate files and objects across the network by building indices for hierarchical information based on attributes from the current node and summaries from other indices. Transitive indexing is designed to be scalable in an environment lacking centralized administrative control.

The Prospero File Access Protocol (PFAP) enables the hierarchical caching and retrieval of bulk data across the Internet. PFAP provides a single uniform interface to multiple caching mechanisms including whole file caching and block caching depending on the reference characteristics of the data and the requirements of clients and servers. PFAP has been integrated with security and payment mechanisms to support controlled access to data objects with restricted access policies.

The GOST project has developed a new efficient garbage collection algorithm for distributed systems using the propagation of last referencable time and registration of links. Garbage collection allows the reclamation of storage for objects which are no longer needed. Support for link maintenance has been developed as part of the garbage collection algorithm, allowing the update of references to objects that have moved across nodes.

Through the work of the GOST project on replication, multiple replication methods and associated consistency algorithms are supported. The specific method to be used may be specified at the granularity of individual objects, files, or directories based on the characteristics and requirements of the individual object, file, or directory. Where existing methods do not meet the needs of an object, application specific methods may be inserted into and are supported by the GOST framework for replication.

The PDS provides a common access protocol through which applications and middleware can retrieve and modify directory information and object attributes. The present implementation of the PDS provides gateways to existing applications such as WWW, FTP, Prospero Mail and a web management tool.

In the area of parallel processing, the GOST project is developing tools that provide support for fault-tolerant and real-time distributed and parallel applications under the Prospero Resource Manager (PRM). Efforts include debugging, compilation, reconfiguration and performance tools that simplify the development of parallel applications, providing support for running sequential applications without re-compilation, improving the communication libraries used by parallel applications and, improving remote I/O performance.

Project Accomplishments (upto July 1998)

Technical Plan for the coming year (1998-99)

Technology Transition

The protocols described in this summary are being discussed at IETF meetings to get necessary input from users of these technologies and to facilitate the transfer of technologies at the completion of the project.

Technology will be transferred through channels that have already been established as part of previous work on the Prospero Directory Service, and the Prospero Resource Manager. Prior releases of PDS have been distributed widely, and it has been used as an embedded service by applications running from more than 100,000 systems on the Internet. Stand-alone modules for incorporation with application are available, allowing the resulting extensions to be used by others.

We have been working with a venture capital firm, Media Technology Ventures to transfer Prospero technology to a startup firm, Brevity Technology, which is designing a meta-directory product around Prospero that will integrate information from multiple legacy systems.

We have also been in discussions with Rendezvous Software, of Palo Alto, California. Rendezvous intends to use the Prospero Directory Service as part of a new product; the details of this product are currently protected by a Non-Disclosure Agreement.

last modified 5/07/03 by Arnold Diaz