一个在线拍卖系统的性能研究外文翻译

一个在线拍卖系统的性能研究外文翻译 外文翻译Performance Investigation of an On-Line Auction System MaterialSource:/0>. 42.9402Author: Jane Hillston, Leila Kloul Abstract: The standard design of on-line auction systems places most of the computational load on the server and its adjacent links, resulting in a bottleneck in the system. In this paper, we investigate the impact, in terms of the performance of the server and its adjacent links, of introducing active nodes into the network. The performance study of the system is done using the stochastic process algebra formalism PEPA.1 Introduction In this paper we investigate the interplay of two emerging technologies: active networks and software agents to support electronic commerce. Active networks are a compelling new initiative in networking. An active network extends a conventional one with the ability for network switches to process data as it is being transmitted. The processing which is to be performed can be customised by the network user on a per-application or even per-message basis. This innovation is a dramatic departure from traditional network design where the emphasis is on the avoidance of examination or modification of data. Active networks are supported by a variety of software technologies, execution environments and node operating systemsSome recent work has focused on the performance gains that active network technology may bring to distributed applications. Examples include active reliable- multi cast and cache routing. In on-line auctions are suggested as applications which might benefit from processing at active nodes within the networkThe Internet offers exciting new prospects for electronic commerce, but it cannot always deliver the performance necessary to make them viable. The electronic transactions take a variety of forms but increasingly there is a move towards agent-based systems in which personalized semi-autonomous software agents act on behalf of consumers or businesses. In many cases such systems rely on the exchange of information and negotiation. If the integrity of such transactions is to be maintained, there is a clear need for timely behaviour of the underlying infrastructureSeveral on-line auction systems have been developed experimentally, such as the AuctionBot system from the University of Michigan, the Fish market Project or the eAuctionHouse which supports combinatorial auctions and which is from the University of Washington. In such systems, competitive behaviour on the part of the bidder relies on a rapid response to submitted bids. However this may be jeopardized by network latency and/or server overload. As suggested, but not investigated in, the in-network processing capabilities provided by an active network appears to provide a solution to this problem. As far as we are aware no thorough performance analysis of such a scenario has been carried outIn this paper, we investigate the performance issues surrounding such a situation. The idea we develop involves replacing standard, basic intermediary nodes of the network by active nodes, the goal being to transfer some tasks from the server to these nodes. This should result in a significant benefit in terms of both system throughput and system latency. The resulting system is then analyses using the stochastic process algebra modeling formalism PEPAThe paper is organized as follows. In Section 2, we describe the on-line auction system we investigate, and the motivation for the approach that we take. Then, in Section 3, after a brief introduction to the modeling formalism we use, PEPA, we present the details of our model. Our solution technique is outlined in Section 4, together with the experiments we conducted and the numerical results we have obtained. Some conclusions of this work, together with the possible extensions, are discussed in Section 5.2 The On-line Auction System In an on-line auction system, a server receives and processes bids from remote software agents representing interested consumers. These semi-autonomous agents submit bids according to a predetermined strategy together with the information that they can ascertain from the server. The server processes bids, either accepting them or rejecting them, depending on their value. In some systems additional attributes may be considered when comparing bids of the same or close valueIn addition to bids, bidder agents may also submit price notification requests, asking the server to tell them the latest bidding price. Note that the bidder agents can never be certain that they have an accurate representation of the current price due to network latency. They can, however, be certain that their current representation is out of date when a submitted bid, which is higher than their idea of the 'current' price, is rejectedThe effectiveness of the bidder agents will depend on the proportion of time that their price information is accurate. Maintaining such accurate information pl