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To enable decentralised actions in very large distributed systems, it is often important to provide the nodes with global knowledge about the values of attributes across all nodes. This paper shows how, given an attribute whose values are distributed across a large decentralised system, each node can efficiently estimate the statistical distribution of(More)
Service-oriented computing is becoming an increasingly popular paradigm for modelling and building distributed systems in open and heterogeneous environments. However, proposed service-oriented architectures are typically based on centralised components, such as service registries or service brokers, that introduce reliability, management, and performance(More)
Peer-to-peer (P2P) systems are characterised by a wide disparity in peer resources and capabilities. In particular, a number of measurements on deployed P2P systems show that peer stability (e.g. uptime) varies by several orders of magnitude between peers. In this paper, we introduce a peer utility metric and construct a self-organising P2P topology based(More)
Despite the recent appearance of self-organizing distributed systems for Mobile Ad Hoc Networks (MANETs) and Peer-to-Peer (P2P) networks, specific theoretical aspects of both their properties and the mechanisms used to establish those properties have been largely overlooked. This has left many researchers confused as to what constitutes a self-organizing(More)
Cloud computing is currently based on hardware virtualization wherein a host operating system provides a virtual machine interface nearly identical to that of physical hardware to guest operating systems. Full transparency allows backward compatibility with legacy software but introduces unpredictability at the guest operating system (OS) level. The time(More)
Service-oriented computing is becoming an increasingly popular paradigm for modelling and building distributed systems in heterogeneous, decentralised, and open environments. However, proposed service-oriented architectures are usually based on centralised components, such as service registries or service brokers, that introduce reliability, management, and(More)
Peer-to-peer environments exhibit a very high diversity in individual peer characteristics ranging by orders of magnitude in terms of uptime, available bandwidth, and storage space. Many systems attempt to exploit this resource heterogeneity by using the best performing and most reliable peers, called super-peers, for hosting system services. However, due(More)
In order to achieve better scalability and reduce latency in handling user requests, many Web applications make extensive use of data replication through caches and content delivery networks. However, in such scenarios data is often placed on untrusted hosts. As a result, existing replication mechanisms open a wide class vulnerabilities, ranging from denial(More)