The rapid growth of the Internet has led to much interest in communication paradigms that support scalability, including multicast and anycast. In this paper, we propose a new message delivery service Programmable Any...
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ISBN:
(纸本)0780374576
The rapid growth of the Internet has led to much interest in communication paradigms that support scalability, including multicast and anycast. In this paper, we propose a new message delivery service Programmable Any-Multicast (PAMcast) - which generalizes both anycast and multicast, by providing a message delivery service to m out of the total n group members, where 1 less than or equal to m less than or equal to n. Such a service has potential applications in a number of areas, including fault tolerant repositories, parallel cache queries, and parallel server downloads. Our architecture is based on a shared tree and managed by a group management protocol with similarities to IGMP. To explore what is possible with limited state and computation at the routers, we consider the implementation of two specific modes of delivery that control how the m receivers are selected. Our balanced mode aims for equal distribution of messages over receivers over time. We find that with relatively little state and computation we can achieve this goal. Our closest mode aims to deliver a packet to the m group members closest (by hop count) to the root of the distribution tree. We find that with modest state and computation we can achieve a probabilistic form of the closest mode.
The paper considers the creation of intelligent solving machines and the arrangement of parallel programming in intelligent distributed multiprocessor systems based on those. There are proposed some main concepts. A s...
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ISBN:
(纸本)0769517315
The paper considers the creation of intelligent solving machines and the arrangement of parallel programming in intelligent distributed multiprocessor systems based on those. There are proposed some main concepts. A system is designed for programming in the C+Graph high-level language. C+Graph provides an efficient operation with knowledge (complicated data structures) and centralized-decentralized control exercised in virtually distributed computation space. Parallel C+Graph programming model is based on a model used for multiple-flow monoprocessor programming of the basic Java language. The model operates in a virtual C+Graph machine network. The ideology proposed can be considered as an efficient development of structural high-level language interpretation when applied to multi-microprocessor systems. Equipment structure of the basic version of intelligent solving machines is considered and some characteristics are discussed.
Modern packet switches and routers are commonly designed using a multi-path architecture, in which the capacities of multiple switch cores are aggregated in order to build a higher capacity system. The local paralleli...
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ISBN:
(纸本)0780374002
Modern packet switches and routers are commonly designed using a multi-path architecture, in which the capacities of multiple switch cores are aggregated in order to build a higher capacity system. The local parallelism within such systems has been found to be the biggest contributing factor to packet re-ordering within the network. This motivates the employment of localized sequence control mechanisms that maintain the ordering of packets, belonging to the same flow, which are forwarded through different paths of the switch. The protocol chosen for this purpose has to maintain a low overhead and exhibit a favorable behavior under arbitrary dispatch patterns and differential delays. In this work, we analyze the performance of the sequence controller of a generic multi-path switch, and establish a sufficient condition which guarantees the stability of the system. Furthermore, we compare the behavior of three practical open-loop sequence control schemes using packet-level simulations. The results presented can be used as a reference to choose an appropriate protocol under the assumed traffic conditions.
Problem frames provide a means of analyzing and decomposing problems. They emphasise the world outside of the computer, helping the developer to focus on the problem domain, instead of drifting into inventing solution...
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ISBN:
(纸本)0769514650;0769514669
Problem frames provide a means of analyzing and decomposing problems. They emphasise the world outside of the computer, helping the developer to focus on the problem domain, instead of drifting into inventing solutions.. However, even modestly complex problems can force us into detailed consideration of the architecture of the solution. This is counter to the intention of the problem frames approach, which is to delay consideration of the solution space until a good understanding of the problem is gained. We therefore extend problem frames, allowing architectural structures, services and artifacts to be considered as part of the problem domain. Through a case study, we show how this extension enhances the applicability of problem frames in permitting an architecture-based approach to software development. We conclude that, through our extension, the applicability of problem frames is extended to include domains with existing architectural support.
In this paper we focus on the single facility capacitated survivable network design problem. We optimize simultaneously the topology, the link dimensioning for the nominal state as well as for the single link failure ...
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ISBN:
(纸本)0780374223
In this paper we focus on the single facility capacitated survivable network design problem. We optimize simultaneously the topology, the link dimensioning for the nominal state as well as for the single link failure state when the survivable conditions are expressed by various rerouting strategies. We present an (mixed) integer mathematical approach that consists of several methodologies. To address the high dimensionality we use Benders' decomposition, and in parallel a Branch-and-Bound method and a cutting plane approach. Beyond the interest of the proposed approach itself, we have considered and compared two well,known restoration technics as local rerouting and end-to-end rerouting. Numerous computational results for realistic instance networks are given to compare these rerouting mechanisms in terms of installed capacities as well as overall costs with respect to topology requirements.
This paper describes the implementation of the OKE, which allows users other than root to load native and fully optimised code in the Linux kernel. Safety is guaranteed by trust management, language customisation and ...
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This paper describes the implementation of the OKE, which allows users other than root to load native and fully optimised code in the Linux kernel. Safety is guaranteed by trust management, language customisation and a trusted compiler. By coupling trust management with the compiler, the OKE is able to vary the level of restrictions on the code running in the kernel, depending on the programmer's privileges. Static sandboxing is used as much as possible to check adherence to the security policies at compile time.
The ever-increasing complexity in network infrastructures is making critical the demand for network monitoring tools. While the majority of network operators rely on low-cost open-source tools based on commodity hardw...
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ISBN:
(纸本)488552184X
The ever-increasing complexity in network infrastructures is making critical the demand for network monitoring tools. While the majority of network operators rely on low-cost open-source tools based on commodity hardware and operating systems, the increasing link speeds and complexity of network monitoring applications have revealed inefficiencies in the existing software organization, which may prohibit the use of such tools in high-speed networks. Although several new architectures have been proposed to address these problems, they require significant effort in re-engineering the existing body of applications. In this paper we present an alternative approach that addresses the primary sources of inefficiency without significantly altering the software structure. Specifically, we enhance the computational model of the Berkeley Packet Filter (BPF) to move much of the processing associated with monitoring into the kernel, thereby removing the overhead associated with context switching between kernel and applications. The resulting packet filter, called xPF, allows new tools to be more efficiently implemented and existing tools to be easily optimized for high-speed networks. We present the design and implementation of xPF as well as several example applications that demonstrate the efficiency of our approach.
Byte-code representations in active networks provide architectural neutrality and code compactness; however, the resulting execution speed is typically poor due to interpretation overhead. This paper shows that the pe...
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Byte-code representations in active networks provide architectural neutrality and code compactness; however, the resulting execution speed is typically poor due to interpretation overhead. This paper shows that the performance of capsule-based active networks can benefit from compiling active network programs into native network processor instructions at traversed routers (just-in-time compilation). A key aspect of the paper is to demonstrate that just-in-time compilers for active networks can be fast and small enough for applicability in the datapath of network processors. The approach has been implemented based on the SNAP active network framework for the PowerNP network processor.
Overlay networks represent a flexible and deployable approach for applications to obtain new network semantics, but they suffer from some efficiency concerns. To support overlay networks efficiently, two new primitive...
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Overlay networks represent a flexible and deployable approach for applications to obtain new network semantics, but they suffer from some efficiency concerns. To support overlay networks efficiently, two new primitives are proposed for implementation in the network layer. Packet Reflection allows end hosts to request short-circuit packet routing and duplication in nearby routers. Path Painting allows multiple end hosts to determine where their disparate paths to a rendezvous point meet, in order to facilitate overlay topology building. Both primitives are incrementally deployable. Numerous applications of these primitives are considered to demonstrate their utility: application level multicast systems with various semantics, an extended Resilient Overlay network with greater latency benefits, and a hierarchy of web caches.
The proceedings contain 79 papers. The topics discussed include: heterogeneous multi-computer system: a new paradigm of parallel processing;low latency communication on DIMMnet-1 network interface plugged into a DIMM ...
ISBN:
(纸本)0769517307
The proceedings contain 79 papers. The topics discussed include: heterogeneous multi-computer system: a new paradigm of parallel processing;low latency communication on DIMMnet-1 network interface plugged into a DIMM slot;program execution control for communication on the fly in dynamic shared memory processor clusters;irregular fine-grain parallel computing based on the slide register window architecture of Hitachi SR2201;architecture-to-task optimization system (ATOS) for parallel multi-mode data-flow architectures on a base of a partially reconfigurable computing platform;parallel architectures and their development on the basis of intelligent solving machines;square interconnection network for data permutation;verification of distributed systems modelled by high-level Petri nets;use of extended semaphore operations in parallel programming on a transputer platform;modelling communication in distributed systems;and analysis of Petri nets by means of concurrent simulation.
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