Institute for Systems Research

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Author: search.filters.author.Kelley, Stephen

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    Managing File Subsystem Data Streams for Databases on Networked Systems
    (1996) Gupta, Sandeep K.; Baras, John S.; Kelley, Stephen; Roussopoulos, Nick; ISR; CSHCN
    One important activity for networked database systems that distribute data across several workstations is moving data between the file and network subsystems. It is possible to create data streams in the operating system kernel. If provided on a system, they allow user level processes to request transfer of data without having t copy it into the user space. This is particularly useful for data whose content or format is not modified during the transfer. In this paper we present a conservative criterion for access and control for the management of such data streams for databases in a networked environment, and define the implementation requirements for achieving the criterion. The approach is to maintain at least the current level of access management. We define the specific implementation semantics that this criterion entails.

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    Hybrid Network Management
    (1996) Baras, John S.; Ball, Michael O.; Karne, Ramesh K.; Whitefield, David; Kelley, Stephen; Jang, Kap D.; Plaisant, Catherine; Roussopoulos, Nick; Stathatos, Kostas; Vakhutinsky, Andrrew; Valluri, Jaibharat; ISR; CSHCN
    We describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid network (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system if specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management, information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Networks Systems.
      A revised version of this technical report has been published in
      Proceedings of the AIAA: 16th International Communications Satellite Systems Conference and Exhibit, Part 1, pp. 490-500, Washington, D.C., February 25- 29, 1996.
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    Integrated Network Management of Hybrid Networks
    (1996) Baras, John S.; Ball, Michael O.; Karne, Ramesh K.; Kelley, Stephen; Jang, Kap D.; Plaisant, C.; Roussopoulos, N.; Stathatos, K.; Vakhutinsky, A.; Valluri, J.; Whitefield, D.; ISR; CSHCN
    We describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid networks (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system is specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Network Systems.
      A revised version of this report has been published in
      Proceedings of the 1st Conference of Commercial Development of Space, Part One, pp. 345-350, Albuquerque, New Mexico, January 7-11, 1996.
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    Simple Calls for Flexible Constructs Using the Traditional File API
    (1996) Gupta, Sandeep; Baras, John S.; Kelley, Stephen; Roussopoulos, N.; ISR
    We present the design for a remote qos control interface to the transport protocol based on existing work for similar applications. This puts together the read/write calls from the traditional file system API and an additional primitive. The addition amounts to programming an operating system data- streaming service which may be provided as a system call or otherwise using the standard techniques. Put together these allow much more than the traditional call based control interface. The resulting interface simplifies the mechanisms for distributed control. Parts of this interface have also been implemented in our ongoing experiments with file transfer.
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    Cues: File Subsystem Data Streams
    (1996) Gupta, Sandeep; Baras, John S.; Kelley, Stephen; Roussopoulos, N.; ISR
    We present a system call which enable directing high performance data transfers with in-kernel streams. The streams are defined and run using abstract data types called Cues, formed over the Unix file subsystem. The system call, named cue() , returns a descriptor, which can be used to write requests to the newly created stream. These requests define the flow of the stream. The abstraction simplifies the design of applications that transfer large amounts of data from files or devices. It also enables high throughput when multiple transfers are in progress. Cue code is compact, modular, and portable. This model also results in a simple mechanism for remotely cueing data flow using standard connections with peer processes. The implementation and tests are also described in this paper.
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    Consistency and Performance of Concurrent Interactive Database Applications
    (1995) Stathatos, K.; Kelley, Stephen; Roussopoulos, N.; Baras, John S.; ISR; CSHCN
    In many modern database applications, there is an emerging need for interactive environments where users directly manipulate the contents of the database. Graphical user interfaces (GUIs) display images of the database which must reflect a consistent up-to-date state of the data with minimum perceivable delay to the user. Moreover, the possibility of several applications concurrently displaying different views of the same database increases the overall system complexity. In this paper, we show how design, performance and concurrency issues can be addressed by adapting existing database techniques. We propose the use of suitable display schemas whose instances compose active views of the database, an extended client caching scheme which is expected to yield significant performance benefits and a locking mechanism that maintains consistency between the GUIs and the database.
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    Next Generation Network Management Technology
    (1994) Atallah, George C.; Ball, Michael O.; Baras, John S.; Goli, Shravan K.; Karne, Ramesh K.; Kelley, Stephen; Kumar, Harsha P.; Plaisant, Catherine; Roussopoulos, Nick; Shneiderman, Ben; Srinivasarao, Mulugu; Stathatos, Kostas; Teittinen, Marko; Whitefield, David; ISR; CSHCN
    Today's telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be ﲭixed media (copper, fiber- optic, radio, and satellite); the sub networks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be ﲭultimedia (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g. data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object-oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment.
      A revised version of this technical report has been published in
      The 12th Symposium on Space Nuclear Power and Propulsion/Commercialization, pp. 75-82, Albuquerque, NM, January 8-12, 1995.