Studies for distributed applications have demonstrated that application quality in distributed computing is strongly dependent on the quality of the underlying communication system. Besides performance characteristics...
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ISBN:
(纸本)9780897919524
Studies for distributed applications have demonstrated that application quality in distributed computing is strongly dependent on the quality of the underlying communication system. Besides performance characteristics the reliability properties of a communication system are playing a predominant role with regard to the quality achievable from applications' point of view. In this paper we study distributed applications with video communication via lossy communication systems. We develop analytical models reflecting transmission of MPEG coded video streams both without and with forward error correction (FEC). these models allow us to determine the optimum amount of redundancy to be used for FEC when communicating via constant bit rate connections. We conclude that FEC algorithms offer the potential for high quality-of-service even in the case of using a communication system with low quality.
Typical reconfigurable machines exhibit shortcomings that make them less than ideal for general-purpose computing. the Garp architecture combines reconfigurable hardware with a standard MIPS processor on the same die ...
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Typical reconfigurable machines exhibit shortcomings that make them less than ideal for general-purpose computing. the Garp architecture combines reconfigurable hardware with a standard MIPS processor on the same die to retain the better features of both. Novel aspects of the architecture are presented, as well as prototype software environment and preliminary performance results. Compared to an UltraSPARC, a Garp of similar technology could achieve speedups ranging from a factor of 2 to as high as a factor of 24 for some useful applications.
A new, simple formal specification is presented for a partitionable view-oriented group communication service. the specification consists of a state machine to express safety requirements and a timed trace property to...
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ISBN:
(纸本)9780897919524
A new, simple formal specification is presented for a partitionable view-oriented group communication service. the specification consists of a state machine to express safety requirements and a timed trace property to express performance and fault-tolerance requirements. the specification is used to construct a totally-ordered-broadcast application, using an algorithm (based on algorithms of Amir, Dolev, Keidar and others) that reconciles information derived from different views of the group. Correctness of the resulting application is proved, and its performance and fault-tolerance analyzed. the specification has a simple implementation, based on a group membership algorithm of Cristian and Schmuck.
the requirements of grand challenge problems and the deployment of gigabit networks makes the network computing framework an attractive and cost effective computing environment with which to interconnect geographicall...
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the requirements of grand challenge problems and the deployment of gigabit networks makes the network computing framework an attractive and cost effective computing environment with which to interconnect geographically distributed processing and storage resources. Our project, Virtual Distributed computing Environment (VDCE), provides a problem-solving environment for high-performance distributed computing over wide area networks. VDCE delivers well-defined library functions that relieve end-users of tedious task implementations and also support reusability. In this paper we present the conceptual design of VDCE software architecture, which is defined in three modules: a) the Application Editor, a user-friendly application development environment that generates the Application Flow Graph (AFG) of an application;b) the Application Scheduler, which provides an efficient task-to-resource mapping of AFG;and c) the VDCE Runtime System, which is responsible for running and managing application execution and monitoring the VDCE resources.
this paper presents a new 32-b reduced instruction set computer/digital signal processor (RISC/DSP) architecture which can be used as a general purpose microprocessor and in parallel as a 16-/32-b fixed-point DSP. thi...
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this paper presents a new 32-b reduced instruction set computer/digital signal processor (RISC/DSP) architecture which can be used as a general purpose microprocessor and in parallel as a 16-/32-b fixed-point DSP. this has been achieved by using RISC design principles for the implementation of DSP functionality. A DSP unit operates in parallel to an arithmetic logic unit (ALU)/barrelshifter on the same register set. this architecture provides the fast loop processing, high data throughput, and deterministic program flow absolutely necessary in DSP applications. Besides offering a basis for general purpose and DSP processing, the RISC philosophy offers a higher degree of flexibility for the implementation of DSP algorithms and achieves higher clock frequencies compared to conventional DSP architectures. the integrated DSP unit provides instruction set support for highly specialized DSP algorithms. Subword processing optimized for DSP algorithms has been implemented to provide maximum performance for 16-b data types. While creating a unified base for both application areas, we also minimized transistor count and ne reduced complexity by using a short instruction pipeline. A parallelism concept based on a varying number of instruction latency cycles made superscalar instruction execution superfluous.
this paper presents HAL's Mercury Interconnect architecture, an interconnect infrastructure designed to link commodity microprocessors, memory, and I/O components into high-performance multiprocessing servers. Bot...
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this paper presents HAL's Mercury Interconnect architecture, an interconnect infrastructure designed to link commodity microprocessors, memory, and I/O components into high-performance multiprocessing servers. Both shared-memory and message-passing systems, as well as hybrid systems are supported by the interconnect. the key attributes of the Mercury Interconnect architecture are: low latency, high bandwidth, a modular and flexible design, reliability/availability/serviceability (RAS) features, and a simplicity that enables very cost-effective implementations. the first implementation of the architecture links multiple 4-processor Pentium Pro based nodes. In a 4-node (16-processor) shared-memory configuration, this system achieves a remote read latency of just over 1 μs, and a maximum interconnect bandwidth of 6.4 GByte/s. Both of these parameters far outpace comparable SCI-based solutions, while utilizing much fewer hardware components.
Clusters of workstations, connected by a fast network, are emerging as a viable architecture for building high-throughput fault-tolerant servers. this type of architecture is more scalable and more cost-effective than...
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ISBN:
(纸本)0818681780
Clusters of workstations, connected by a fast network, are emerging as a viable architecture for building high-throughput fault-tolerant servers. this type of architecture is more scalable and more cost-effective than a tightly coupled multiprocessor and may achieve as good a throughput. this paper explores several combinations of fault tolerance (FT) and lend-balancing (LB) schemes, and compares their impact on the maximum throughput achievable by the system, and on its survivability. In particular we show that the FT scheme has an effect on the throughput of the system, while the LB scheme affects the ability of the system to override failures. We study the scalability of he different schemes under different loads and failure conditions. Our simulations take into consideration the overhead of each scheme, the network contention, and the resource loads.
Withthe growing presence of multimedia-enabled systems, we will see an integration of collaborative computing concepts into future scientific and technical workplaces. Desktop teleconferencing is common today, while ...
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Withthe growing presence of multimedia-enabled systems, we will see an integration of collaborative computing concepts into future scientific and technical workplaces. Desktop teleconferencing is common today, while more complex teleconferencing technology that relies on the availability of multipoint-enabled tools is starting to become available on PCs. A critical problem when using these collaborative tools is archiving multistream, multipoint meetings and making the content available to others. Ideally, one would like the ability to capture, record, play back, index, annotate, and distribute multimedia stream data as easily as we currently handle text or still-image data. the Argonne Voyager project is exploring and developing media server technology needed to provide such a flexible, virtual multipoint recording/playback capability. In this article we describe the motivating requirements, architecture, implementation, operation, performance, and related work.
this paper presents an implementation of replicated state machines in asynchronous distributed environments prone to node failures and network partitions. this implementation has several appealing properties: It guara...
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ISBN:
(纸本)0818681780
this paper presents an implementation of replicated state machines in asynchronous distributed environments prone to node failures and network partitions. this implementation has several appealing properties: It guarantees that progress will be made whenever a majority of replicas can communicate with each other;it allows minority partitions to continue providing service for idempotent requests;it offers the application the choice between optimistic or safe message delivery. performance measurements have shown that our implementation incurs low latency and achieves highthroughput while providing globally consistent replicated state machine semantics.
Faster networks, faster processors, and standardized protocols have enabled the emergence of interactive applications running over commercial networks such as the Internet, In such applications, multiple users interac...
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Faster networks, faster processors, and standardized protocols have enabled the emergence of interactive applications running over commercial networks such as the Internet, In such applications, multiple users interact with one another by exchanging real-time information such as user position and orientation in a virtual world, live and recorded audio, video, and text. these applications include interactive shopping, team training, virtual meeting rooms, and multi-player games. However, to date, these interactive systems have supported a limited number of information types, offered limited scalability, and have failed to account for a heterogeneous network and processor environment. In this paper, we describe the design and implementation of InVerse, an infrastructure that supports real-time interactive applications on the Internet. InVerse provides a common backplane for disseminating and managing multiple real-time data streams. Within this general-purpose structure, the InVerse system maximizes scalability by implementing a hybrid communications architecturethat adapts itself to available network bandwidth, observed network latency, installed network security measures, and available services such as multicast.
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