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Fiscal 1994 Project Portfolio Report
Duane Northcutt, Principal Investigator
duane.northcutt@Eng.Sun.COM
Overall Objective
To develop and apply the technology required to better support the needs of an
application domain that can benefit from Sun's strengths in machine
architecture, networking and system software--i.e., applications that deal with continuous, time-critical media.
Objective for FY94
To engage in the exploration of the opportunities offered by the application of
money, market institutions, and general micro-economic principles to the problems of system-level resource management, and to the management of higher-level (including human) assets in distributed systems.
Description
A key assumption of this work is that the workstation is evolving from primarily a compute device into a communications device, and as such, it must lend greater support to a new class of applications, i.e., ones whose value to the user varies as a functi
on of time. As the move towards right-sizing continues, it is becoming increasingly important to provide more effective management of system resources in order to deliver the greatest degree of value possible to the end users. Furthermore, the increase in
resources provided by advances in base technology is not providing a solution to this problem--already visible are the emerging effects of the Agoric Paradox, i.e., the
increased availability of resources increases the need for their management
in an automatic and principled manner.
The technology developed by this project, when applied to Sun platforms,
should result in increased system effectiveness when executing programs with
significant temporal components (e.g., any interactive application). Users will
receive a higher degree of perceived value from their systems as a result of the systems' awareness of application timeliness needs, and their active efforts to meet application-defined time constraints.
The two key notions introduced into the workstation by this effort are (global) time and value. The desired improvements in system performance are achieved through the introduction of notions of time-varying global value to the management of
such resources as (high-speed) networks, processing elements, and storage.
Both resource scheduling theory and principles of micro-economics are being applied to the task of optimizing the value delivered by the resources that comprise large scale distributed systems. By introducing the notion of time, system resource management
decisions can be made so that the allocation of resources ensures that computations obtain their needed resources at the most effective points in time. By introducing the notion of price as a compact, modular means of expressing global value, contention
for shared system resources can be resolved in a manner that maximizes the value that the system delivers to its users. Associating prices with request for resources also provides the basis for quantifying the overall importance of a given resource (as se
parate from the utilization of the resource).
In addition to enabling more efficient resource management by ensuring that
the most important activities receive the available resources, the introduction of prices allows various experiments to be performed in the use of user level (dis) incentives to (dis) encourage specific behavior modes.
In order to address the end-to-end implications of providing enhanced support for time-critical media applications, work must be done at all levels of the system--from the development of representative applications, to the creation of the appropriate new
programming frameworks and abstractions, through the modification and extension of operating system and network facilities, down to the introduction of necessary platform level features of the workstation I/O architecture.
Accomplishments
This year's work was marked by significant results in the following key areas:
- We provided modifications to product software groups to enhance support for multimedia applications and to offer user-visible improvements in system performance across a wide range of different application areas
- We explored the use of micro-economic principles in the management of
resources (from the system to the user level) in order to deliver a higher
degree of value to end users
- We expanded the project's trial ATM network to become the group's primary network interface, and assumed the role as a center of practical experience in the area of ATM networking for Sun
- We developed time-critical-media based applications, which are
representative of the emerging class of new applications and fully exploit
the capabilities of Sun's new system hardware
- We initiated and supported a set of experiments in high-performance I/O
architecture
- We created artifacts that serve as both necessary building-blocks for the
project's research and prototype products--including the Sun Tuner product, currently available through SunExpress
Enhancements to Existing Sun Products
A number of enhancements were made this year to the existing Sun product line as spin-offs of research performed by the group. In particular, a number of modifications were made to the Solaris operating system that provided significant improvements to use
r level performance. A number of modifications suggested by experiments the group has performed in the area of processor scheduling have been incorporated into the 2.3 and 2.4 releases of Solaris. These modifications serve to enhance system performance in
a number of ways, including: providing a greater degress of user level control over system behavior; improving the ability of the system to scale larger numbers of active processes; and presenting the users with additional information needed for performa
nce tuning. In addition, enhancements were made to products in the user interface and compiler area (i.e., csh and the C compiler).
Initial Experiments with Agoric System
With the help of a group of engineers and economists with special expertise in the area of computational markets (i.e., Agoric's Inc.), an investigation was begun into the application of micro-economic principles to the management of resources in distribu
ted systems.
A demonstration of the application of Agoric System principles was a key part of the Sun exhibit at InterOp/Networld'94 in Las Vegas, where the price of using a local ATM network was set by the instantaneous demand for bandwidth as defined by a dyn
amic auction process. In addition, a distributed banking facility was created to handle the transactions generated by a video-on-demand application that was capable of operating at a range of different quality levels, based on the amount of
bandwidth available at a range of different prices.Sun Interactive is using this demo as part of its sales pitch to customers.
Exploration and Deployment of Operational ATM Networks
This fiscal year saw the expansion of the project's small scale, exploratory ATM network into a larger scale enterprise supporting the day-to-day operational needs of the entire group.
Through the use of Sun's initial prototype host interface SAHI-1 Bus boards and switches from both Synoptics and Fore Systems, the project has been running on an OC-3 (155Mbps optical) network with over thirty hosts since early CY94.
A number of test and demonstration applications have been developed by the group to exercise the ATM network, including a high-performance network video application that is capable of delivering end-to-end (disk to display) performance in excess of 56Mbps
, with standard user-mode processes at both the source and destination ends. This test program has been widely distributed and used both within and outside Sun.
Work has also been underway to enable cooperative work with research partners at Stanford University and XeroxPARC via the Bay Area ATM trials--Bagnet and BMAN. Infrastructure and initial applications have been developed and initial experiments are beginn
ing.
Development of Representative Time-Critical Media Applications
A suite of example applications have been developed by the TCM group to enable the exploration of the key research objectives of the project. In an effort to explore concepts of electronic commerce with SML, the TCM project created a framework known as th
e SML Interactive Services Network that provides a collection of new (ATM based) interactive audio and video applications. These initial applications are used to illustrate various aspects of computational markets and form the basis for wider experiments
with network commerce within SML.
Creation of Foundations for High-Performance I/O Experiments
As a result of this project's work, it is believed that improvements in workstation I/O architectures are needed in order to meet the demands of many continuous media applications. To this end, a project (IOSIMM--working jointly with SMCC's Technology Dev
elopment group) was established to explore the potential of achieving high-bandwidth and low-latency I/O connections by attaching I/O devices directly into the system's primary memory.
A specially modified memory unit was developed for the SPARCstation 20 that permits direct access to physical memory. In addition, a video input/output converter board was constructed and the resulting system was demonstrated at SIGGRAPH'94--taking broadc
ast-quality (D1) video streams in, operating on them in real-time, and displaying them on a high-resolution (2Mpixel) monitor.
References
Publications
"Transmitting Data Within Video Signals," J. D. Northcutt, SMLI 94-0051.
"SVR4 UNIX Scheduler Unacceptable for Multimedia Applications," J. Nieh,
J. Hanko, J. Northcutt, G. Wall, SMLI 93-0348.
"Bus Bandwidth Management in a High Resolution Video Workstation,"
G. Wall, J. Hanko, J. Northcutt, Third International Workshop on Network
and Operating System Support for Digital Audio and Video. Springer-Verlag,
1993. SMLI 92-0344.
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