Perspectives on optimistically replicated, peer-to-peer filing

Page, Thomas W.; Guy, Richard; Heidemann, John; Ratner, David; Reiher, Peter; Goel, Ashvin; Kuenning, Geoff; Popek, Gerald J.

doi:10.1002/(sici)1097-024x(199802)28:2<155::aid-spe155>3.0.co;2-5

Cited by 58 publications

(43 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is substantial peer-to-peer work in the file system and OS literature that is relevant, including the Ficus [23], JetFile [13], Bayou [28] projects. All of them are replicated storage systems based on the peer-to-peer architecture.…”

Section: Related Workmentioning

confidence: 99%

Effects of power conservation, wireless coverage and cooperation on data dissemination among mobile devices

Papadopouli

Schulzrinne

2001

Proceedings of the 2nd ACM International Symposium on Mobile Ad Hoc Networking &Amp; Computing - MobiHoc '01

143

View full text Add to dashboard Cite

This paper presents 7DS, a novel peer-to-peer data sharing system. 7DS is an architecture, a set of protocols and an implementation enabling the exchange of data among peers that are not necessarily connected to the Internet. Peers can be either mobile or stationary. It anticipates the information needs of users and fulfills them by searching for information among peers. We evaluate via extensive simulations the effectiveness of our system for data dissemination among mobile devices with a large number of user mobility scenarios. We model several general data dissemination approaches and investigate the effect of the wireless coverage range, 7DS host density, query interval and cooperation strategy among the mobile hosts. Using theory from random walks, random environments and diffusion of controlled processes, we model one of these data dissemination schemes and show that the analysis confirms the simulation results for this scheme.

show abstract

Section: Related Workmentioning

confidence: 99%

Effects of power conservation, wireless coverage and cooperation on data dissemination among mobile devices

Papadopouli

Schulzrinne

2001

Proceedings of the 2nd ACM International Symposium on Mobile Ad Hoc Networking &Amp; Computing - MobiHoc '01

143

View full text Add to dashboard Cite

show abstract

“…Each replica obtains a quorum by gathering weighted votes from other replicas in the system and by providing its vote to others. Similarly, Coda [14] and Ficus [17] provide support for disconnected operations in the domain of distributed file systems. Each mobile device can modify its cached files while disconnected.…”

Section: Related Workmentioning

confidence: 99%

Neighborhood-Consistent Transaction Management for Pervasive Computing Environments

Perich

Joshi

Yesha

et al. 2003

Lecture Notes in Computer Science

View full text Add to dashboard Cite

Abstract. This paper examines the problem of transaction management in pervasive computing environments and presents a new approach to address them. We represent each entity as a mobile or static semi-autonomous device. The purpose of each device is to satisfy user queries based on its local data repository and interactions with other devices currently in its vicinity. Pervasive environments, unlike traditional mobile computing paradigm, do not differentiate between clients and servers that are located in a fixed, wired infrastructure. Consequently, we model all devices as peers. These environments also relax other assumptions made by mobile computing paradigm, such as the possibility of reconnection with a given device, support from wired infrastructure, or the presence of a global schema. These fundamental characteristics of pervasive computing environments limit the use of techniques developed for transactions in a "mobile" computing environments. We define an alternative optimistic transaction model whose main emphasis is to provide a high rate of successful transaction terminations and to maintain a neighborhood-based consistency. The model accomplishes this via the help of active witnesses and by employing an epidemic voting protocol. The advantage of our model is that it enables two or more peers to engage in a reliable and consistent transaction while in a pervasive environment without assuming that they can talk to each other via infrastructure such as base stations. The advantage of using active witnesses and an epidemic voting protocol is that transaction termination does not depend on any single point of a failure. Additionally, the use of an epidemic voting protocol does not require all involved entities to be simultaneously connected at any time and, therefore, further overcomes the dynamic nature of the environments. We present the implementation of the model and results from simulations.

show abstract

“…Typically, reconciliation takes place between two replicas. Updates are tracked using either logging [13] or scanning [10]. Conflicts occur when different replicas of the same file are updated after the most recent reconciliation.…”

Section: Introductionmentioning

confidence: 99%

Using Permuted States and Validated Simulation to Analyze Conflict Rates in Optimistic Replication

2007

View full text Add to dashboard Cite

Optimistic replication provides high data availability in the presence of network outages. Although widely deployed, this relaxed consistency model introduces concurrent updates, whose behavior is poorly understood due to the vast state space.This paper introduces the notion of permuted states to eliminate system states that are redundant and unreachable, which can constitute the majority of states (4069 out of 4096 for four replicas). With the aid of permuted states, we are for the first time able to construct analytical models beyond the two-replica case. By examining the analysis for 2 to 4 replicas, we can demystify the process of forming identical conflicts-the most common conflict type at high replication factors. Additionally, we have automated and optimized the generation of permuted states, which allows us to explore higher replication factors (up to 10 replicas) using hybrid techniques. It also allows us to validate our results with existing simulations based on actual replication mechanisms, which previously were analytically validated with only one pair of replicas.Finally, we have discovered that update locality and bimodal access patterns are the primary factors contributing to the formation of identical conflicts.

show abstract

Perspectives on optimistically replicated, peer-to-peer filing

Cited by 58 publications

References 26 publications

Effects of power conservation, wireless coverage and cooperation on data dissemination among mobile devices

Effects of power conservation, wireless coverage and cooperation on data dissemination among mobile devices

Neighborhood-Consistent Transaction Management for Pervasive Computing Environments

Using Permuted States and Validated Simulation to Analyze Conflict Rates in Optimistic Replication

Contact Info

Product

Resources

About