This paper presents a parallel genetic algorithm to the Steiner Problem in networks. Several previous papers have proposed the adoption of GAs and others metaheuristics to solve the SPN demonstrating the validity of t...
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ISBN:
(纸本)088986392X
This paper presents a parallel genetic algorithm to the Steiner Problem in networks. Several previous papers have proposed the adoption of GAs and others metaheuristics to solve the SPN demonstrating the validity of their approaches. This work differs from them for two main reasons: the dimension and the characteristics of the networks adopted in the experiments and the aim from which it has been originated. The reason that aimed this work was namely to build a comparison term for validating deterministic and computationally inexpensive algorithms which can be used in practical engineering applications, such as the multicast transmission in the Internet. On the other hand, the large dimensions of our sample networks require the adoption of a parallel implementation of the Steiner GA, which is able to deal with such large problem instances.
Peer-to-peer (P2P) networking is designed for sharing resources at the edge of the Internet. Searching in file-sharing P2P networks has been an important research topic, and it has drawn significant attention recently...
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ISBN:
(纸本)9780889867048
Peer-to-peer (P2P) networking is designed for sharing resources at the edge of the Internet. Searching in file-sharing P2P networks has been an important research topic, and it has drawn significant attention recently. Hints can be utilized to improve query success rates. Determining how to efficiently and effectively propagate hints is a challenging issue. In this paper, we propose a searching protocol called HS-SDBF (Hint-based Search by Scope Decay Bloom Filter) that addresses this issue. HS-SDBF uses a data structure named SDBF (Scope Decay Bloom Filter) to represent and propagate probabilistic hints. Compared to existing proactive schemes, HS-SDBF can answer many more queries successfully at a lower amortized cost considering both the query traffic and hint propagation traffic. The experimental results support the performance improvement of our protocol.
Resource management is central to grid computing and plays a vital role in ensuring that the jobs execute both successfully and economically on the grid. In this paper, we present an analysis of the factors affecting ...
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Resource management is central to grid computing and plays a vital role in ensuring that the jobs execute both successfully and economically on the grid. In this paper, we present an analysis of the factors affecting resource allocation and illustrate the same in the case of disk space aggregation. We explore the feasibility of a comprehensive resource aggregation network that can bind fragmented resources together to provide a unified resource for grid jobs. We provide an implementation framework to realise resource aggregation, by adopting and enhancing the Alchemi [1] framework.
Self-stabilization is a theoretical framework of non-masking fault-tolerant distributed algorithms. A self-stabilizing system tolerates any kind and any finite number of transient faults, such as message loss, memory ...
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ISBN:
(纸本)0889865906
Self-stabilization is a theoretical framework of non-masking fault-tolerant distributed algorithms. A self-stabilizing system tolerates any kind and any finite number of transient faults, such as message loss, memory corruption, and topology change. Because message loss and topology change occur so frequently in mobile ad hoc networks, distributed algorithms on them should tolerate such events. In this paper, we propose a self-stabilizing distributed algorithm for computing a 5-spanner, which can be used, for example, as a basis for computing virtual backbone or routing in mobile ad hoc networks.
Firewalls, and packet classification in general, are becoming more and more significant as data rates soar and hackers become increasingly sophisticated - and more forceful. In this paper, we present a new packet-clas...
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ISBN:
(纸本)088986392X
Firewalls, and packet classification in general, are becoming more and more significant as data rates soar and hackers become increasingly sophisticated - and more forceful. In this paper, we present a new packet-classification approach that uses set theory to classify packets. This approach has significant theoretical advantages over current approaches. We demonstrate its practicality by implementing a firewall subsystem in Linux which approaches the performance of today's naive packet-filtering implementations.
This paper presents improvements of the parallel-FIMI method for statical load balancing of mining of all frequent itemsets on a distributed-memory (DM) parallel machine. This method probabilistically partitions the s...
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ISBN:
(纸本)9780889867048
This paper presents improvements of the parallel-FIMI method for statical load balancing of mining of all frequent itemsets on a distributed-memory (DM) parallel machine. This method probabilistically partitions the space of all frequent itemsets into partitions of approximately the same size. The improvements consist in paralelization of the approximate partitioning of the search space and of dynamic reordering of items during construction of prefix-based equivalence classes. The new versions of the method achieve nearly linear speedups up to 10 processors.
Comprehensive security policies are an integral part of creating a secure network and commonly firewalls are used to accomplish this. Firewalls inspect and filter traffic arriving or departing a network by comparing p...
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ISBN:
(纸本)0889865701
Comprehensive security policies are an integral part of creating a secure network and commonly firewalls are used to accomplish this. Firewalls inspect and filter traffic arriving or departing a network by comparing packets to a set of rules and performing the matching rule action, which is accept or deny. Unfortunately, traffic inspection of this type can impose significant delays on traffic due to the complexity and size of policies. Therefore, improving firewall performance is important, given the next generation of high-speed networks. This paper investigates the performance of a function parallel firewall architecture that distributes the original policy across an array of firewalls. A packet is processed by all the firewalls simultaneously and a gate then makes a final decision (accept or deny) based on the results of the individual firewalls. Since the individual firewalls have fewer rules to process (only a portion of the original policy), the function parallel system has lower delays (e.g. 74% lower for a four firewall array) and a higher throughput than other data parallel (load-balancing) firewalls. However, the performance increase is dependent on the speed of the gate. The potential speed increase and the impact of the gate will be demonstrated empirically.
In this paper three different Service Discovery approaches based on centralized and distributed registries within so called Virtual Organizations are assessed. The first approach is a centralized model, the second a c...
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ISBN:
(纸本)088986392X
In this paper three different Service Discovery approaches based on centralized and distributed registries within so called Virtual Organizations are assessed. The first approach is a centralized model, the second a completely decentralized and the third is a hybrid of both models. The Grid environment is typically comprised of heterogeneous resources over wide-area networks, It addresses all distributedcomputing issues, especially the problem of service discovery. The benefits and drawbacks of all three models are discussed and a comparison regarding issues such as administration, management, scalability and security is followed. Furthermore, measurements are executed in order to investigate the performance of all three models, and a reliability analysis is conducted.
Large clustered computers provide low-cost compute cycles, and therefore have promoted the development of sophisticated parallel-programming algorithms based on the Message Passing Interface. Storage platforms, howeve...
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ISBN:
(纸本)088986568X
Large clustered computers provide low-cost compute cycles, and therefore have promoted the development of sophisticated parallel-programming algorithms based on the Message Passing Interface. Storage platforms, however, fall to keep pace with similar advances. This paper compares standard 4X InfiniBand (IB) to 10-Gigabit Ethernet (GbE) for Use as a common storage infrastructure in addition to message passing. Considering IB's native ability to accelerate protocol processing in hardware, the Ethernet hardware in this study provided similar acceleration using TCP Offload Engines. We evaluated their I/O perfon-nance using the IOZONE benchmark on the iSCSI-based TerraGRID parallel filesystem. Our evaluations show that 10GbE, with or without protocol-offload, offered better throughput and latency than IB to socket-based applications. Although protocol-offload in both 10GbE and IB demonstrated significant improvement in I/O performance, large amount of CPU are still being consumed to handle the associated data-copies and interrupts. The emerging RDMA technologies hold promises to remove the remaining CPU overhead. We plan to continue our study to research the applications of RDMA in parallel I/O.
An important problem in the construction of distributed systems is the openness of these systems to dynamic computations, i.e. the ability of these systems to support new infrastructure services and applications durin...
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ISBN:
(纸本)088986392X
An important problem in the construction of distributed systems is the openness of these systems to dynamic computations, i.e. the ability of these systems to support new infrastructure services and applications during their operations. Algorithms and services have been designed using several system models: synchronous, asynchronous bonded-delay, asynchronous, etc. In practice, most of the existing systems implement a limited number of system models, and can be hardly adapted to new applications. For example, a metropolitan area network used to develop a reliable data communication system can hardly support real-time audio-communications. In this paper, we describe new principles and an architectural basis for the development of distributed system infrastructures supporting multiple system models, that can be dynamically modified to be adapted to new application requirements, using programmable networks. The paper provides a framework for the application of network programmability and active networks to distributed system design, and their use to dynamically enforce multiple and concurrent system models. Such systems can be used to support multiple application profiles with the same computing and communication resources.
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