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arXiv 0705.2065cs.DCcs.PF
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动态P2P系统中消息发送的平均场模型

Mean Field Models of Message Throughput in Dynamic Peer-to-Peer Systems

Aaron Harwood, Olga Ohrimenko

摘要:

对等系统的流失率直接限制了消息可以有效地传递给一组对等点的速率。这些限制与拓扑和消息传输延迟无关。在本文中,我们考虑一个对等网络,基于Engset模型,其中的同行到达和离开独立随机。我们展示了如何到达和离开率直接限制的容量,消息流被广播到所有其他同行,通过推导平均场模型,准确地描述了系统的行为。我们的模型涵盖了单位和更一般的K缓冲区的情况下,即一个对等体可以在任何一个时间缓冲最多k个消息,我们给出了结果为单源和多源消息流。我们定义为每单位时间的对等消息的覆盖率,即在一些对等端接收消息的速率,并表明覆盖率是有限的流失率和缓冲区大小。我们的理论引入了一个即时消息交换(IME)模型,并提供了一个更复杂的系统进一步分析的模板。使用IME模型,并假设随机过程,我们已经获得了非常准确的方程的系统动力学在各种有趣的情况下,使我们能够调整对等系统。对于一般过程和应用非瞬时模型时,我们是否能保持这种精度还有待观察。

英文摘要:

The churn rate of a peer-to-peer system places direct limitations on the rate at which messages can be effectively communicated to a group of peers. These limitations are independent of the topology and message transmission latency. In this paper we consider a peer-to-peer network, based on the Engset model, where peers arrive and depart independently at random. We show how the arrival and departure rates directly limit the capacity for message streams to be broadcast to all other peers, by deriving mean field models that accurately describe the system behavior. Our models cover the unit and more general k buffer cases, i.e. where a peer can buffer at most k messages at any one time, and we give results for both single and multi-source message streams. We define coverage rate as peer-messages per unit time, i.e. the rate at which a number of peers receive messages, and show that the coverage rate is limited by the churn rate and buffer size. Our theory introduces an Instantaneous Message Exchange (IME) model and provides a template for further analysis of more complicated systems. Using the IME model, and assuming random processes, we have obtained very accurate equations of the system dynamics in a variety of interesting cases, that allow us to tune a peer-to-peer system. It remains to be seen if we can maintain this accuracy for general processes and when applying a non-instantaneous model.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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