| 1. |
- Aberer, Karl, et al.
(författare)
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The Essence of P2P : A Reference Architecture for Overlay Networks
- 2005
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Ingår i: Fifth IEEE International Conference on Peer-to-Peer Computing, Proceedings. - 0769523765 ; , s. 11-20
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Konferensbidrag (refereegranskat)abstract
- The success of the P2P idea has created a huge diversity of approaches, among which overlay networks, for example, Gnutella, Kazaa, Chord, Pastry, Tapestry, P-Grid, or DKS, have received specific attention from both developers and researchers. A wide variety of algorithms, data structures, and architectures have been proposed. The terminologies and abstractions used, however have become quite inconsistent since the P2P paradigm has attracted people from many different communities, e.g., networking, databases, distributed systems, graph theory, complexity theory, biology, etc. In this paper we propose a reference model for overlay networks which is capable of modeling different approaches in this domain in a generic manner It is intended to allow researchers and users to assess the properties of concrete systems, to establish a common vocabulary for scientific discussion, to facilitate the qualitative comparison of the systems, and to serve as the basis for defining a standardized API to make overlay networks interoperable.
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| 2. |
- Al-Shishtawy, Ahmad, et al.
(författare)
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A design methodology for self-management in distributed environments
- 2009
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Ingår i: IEEE International conference on Computational Science and Engineering. - 9780769538235 ; , s. 430-436
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Konferensbidrag (refereegranskat)abstract
- Autonomic computing is a paradigm that aims at reducing administrative overhead by providing autonomic managers to make applications selfmanaging. In order to better deal with dynamic environments, for improved performance and scalability, we advocate for distribution of management functions among several cooperative managers that coordinate their activities in order to achieve management objectives. We present a methodology for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to design and development of a distributed storage service as a case study. The storage service prototype has been developed using the distributing component management system Niche. Distribution of autonomic managers allows distributing the management overhead and increased management performance due to concurrency and better locality.
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| 3. |
- Arad, Cosmin, et al.
(författare)
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Building and Evaluating P2P Systems using the Kompics Component Framework
- 2009
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Ingår i: 2009 IEEE NINTH INTERNATIONAL CONFERENCE ON PEER-TO-PEER COMPUTING (P2P 2009). - NEW YORK : IEEE. - 9781424450664 ; , s. 93-94
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Konferensbidrag (refereegranskat)abstract
- We present a framework for building and evaluating P2P systems in simulation, local execution, and distributed deployment. Such uniform system evaluations increase confidence in the obtained results. We briefly introduce the Kompics component model and its P2P framework. We describe the component architecture of a Kompics P2P system and show how to define experiment scenarios for large dynamic systems. The same experiments are conducted in reproducible simulation, in real-time execution on a single machine, and distributed over a local cluster or a wide area network. This demonstration shows the component oriented design and the evaluation of two P2P systems implemented in Kompics: Chord and Cyclon. We simulate the systems and then we execute them in real time. During real-time execution we monitor the dynamic behavior of the systems and interact with them through their web-based interfaces. We demonstrate how component-oriented design enables seamless switching between alternative protocols.
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| 4. |
- Arad, Cosmin, et al.
(författare)
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GODS: Global Observatory for Distributed Systems
- 2007. - 1
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We propose GODS, an ecosystem for the evaluation and study of world-wide distributed and dynamic systems under a realistic emulated network environment. GODS allows the evaluation of a system's actual implementation in reproducible experiments, collecting global knowledge about the system state. Furthermore, GODS addresses the problems of debugging distributed algorithms, performance tuning, measuring bandwidth consumption, regression testing, and benchmarking similar systems, thus offering a complete evaluation environment for distributed applications. Our framework uses ModelNet for the network emulation and enhances that by (1) adding dynamism by varying link properties, partitioning the network and emulating churn, (2) offering global knowledge about the observed system by gathering statistics and events and (3) enabling the user to easily deploy, manage and monitor complex, large-scale distributed systems.
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| 5. |
- Arad, Cosmin, et al.
(författare)
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Practical Protocol Composition, Encapsulation and Sharing in Kompics
- 2008
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Ingår i: SASOW 2008. - LOS ALAMITOS : IEEE COMPUTER SOC. - 9781424434688 ; , s. 266-271
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Konferensbidrag (refereegranskat)abstract
- At the core of any distributed system is a set of concurrent distributed algorithms that coordinate the functionality of the distributed system. We present a software architecture, Kompics that is component-based and compositional which facilitates building distributed protocols. The underlying computation model subsumes that of event-based systems, SEDA (staged event-driven architecture.) and thread-based models. We illustrate various salient features of Kompics such as ease of use, compositionality and configurability through a series of well chosen distributed protocols.
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| 6. |
- Brand, Per, 1952-
(författare)
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The design philosophy of distributed programming systems : the Mozart experience
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Distributed programming is usually considered both difficult and inherently different from concurrent centralized programming. It is thought that the distributed programming systems that we ultimately deploy, in the future, when we've worked out all the details, will require a very different programming model and will even need to be evaluated by new criteria. The Mozart Programming System, described in this thesis, demonstrates that this need not be the case. It is shown that, with a good system design, distributed programming can be seen as an extended form of concurrent programming. This is from the programmer's point-of-view; under the hood the design and implementation will necessarily be more complex. We relate the Mozart system with the classical transparencies of distributed systems. We show that some of these are inherently on the application level, while as Mozart demonstrates, others can and should be dealt with on the language/system level. The extensions to the programming model, given the right concurrent programming base, are mainly concerned with non-functional properties of programs. The models and tuning facilities for failure and performance need to take latency, bandwidth, and partial failure into account. Other than that there need not be any difference between concurrent programming and distributed programming. The Mozart Programming System is based on the concurrent programming language Oz, which integrates, in a coherent way, all three known concurrency or thread-interaction models. These are message-passing (like Erlang), shared objects (like Java with threads) and shared data-flow variables. The Mozart design philosophy is thus applicable over the entire range of concurrent programming languages/systems. We have extracted from the experience with Mozart a number of principles and properties that are applicable to the design and implementation of all (general-purpose) distributed programming systems. The full range of the design and implementation issues behind Mozart are presented. This includes a description of the consistency protocols that make transparency possible for the full language, including distributed objects and distributed data-flow variables. Mozart is extensively compared with other approaches to distributed programming, in general, and to other language-based distributed programming systems, in particular
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| 7. |
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| 8. |
- Dowling, Jim, et al.
(författare)
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Developing a Distributed Electronic Health-Record Store for India
- 2008
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Ingår i: ERCIM News. - 0926-4981 .- 1564-0094. ; :75, s. 56-57
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Forskningsöversikt (populärvet., debatt m.m.)abstract
- The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India. There has been much recent interest in information services that offer to manage an individual's healthcare records in electronic form, with systems such as Microsoft HealthVault and Google Health receiving widespread media attention. These systems are, however, proprietary and fears have been expressed over how the information stored in them will be used. In relation to these developments, countries with nationalized healthcare systems are also investigating the construction of healthcare information systems that store Electronic Health Records (EHRs) for their citizens.
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| 9. |
- Dowling, Jim, et al.
(författare)
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Improving ICE service selection in a P2P system using the gradient topology
- 2007
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Ingår i: First IEEE International Conference on Self-Adaptive and Self-Organizing Systems. - 9780769529066 ; , s. 285-288
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Konferensbidrag (refereegranskat)abstract
- Internet Connectivity Establishment (ICE) is becoming increasingly important for P2P systems on the open Internet, as it enables NAT-bound peers to provide accessible services. A problem for P2P systems that provide ICE services is how peers discover good quality ICE servers for NAT traversal, that is, the TURN and STUN servers that provide relaying and hole-punching services, respectively. Skype provides a P2P-based solution to this problem, where super-peers provide ICE services. However experimental analysis of Skype indicates that peers perform a random walk of super-peers to find one with an acceptable round-trip latency. In this paper, we discuss a self organizing approach to discovering good quality ICE servers in a P2P system based the walk Topology. The walk Topology uses information about each peer’s ability to provide ICE services (open IP address, available bandwidth and expected session times) to construct a topology where the “better” peers for providing ICE services cluster in the center of the topology; this adaptation of the super-peer search space reduces the problem of finding a good quality ICE server from a random walk to a gradient ascent search.
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| 10. |
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