Peer-to-peer (P2P) computing can be defined as the sharing of computer resources and services by direct exchange between the participating nodes. Since Napster’s introduction in the late 90s, the area has received increasing attention from the research community and the general public. Peers in P2P systems typically define an overlay network topology by keeping a number of connections to other peers, their “friends,” and implementing a maintenance protocol that continuously repairs the overlay as new members join and others leave the
system.
Due in part to the autonomous nature of peers, their mutual dependency, and their astoundingly large populations, the transiency of peers (a.k.a. churn) and its implications on the overall system’s performance have recently attracted the attention of the research community. A well-accepted metric of churn is node session time – the time from the node’s joining to its subsequent leaving from the system. Measurement studies of deployed P2P systems have reported median session times varying from one hour to one minute.
Yi Qiao, Dong Lu, Fabián E. Bustamante, Peter Dinda, Stefan Birrer Improving Peer-to-Peer Performance Through Server-Side Scheduling Journal Article In ACM Transactions on Computer Systems (TOCS), 26 (4), 2008. Abstract | BibTeX | Links:  @article{P2PPSSS,
title = { Improving Peer-to-Peer Performance Through Server-Side Scheduling},
author = {Yi Qiao and Dong Lu and Fabián E. Bustamante and Peter Dinda and Stefan Birrer},
url = {https://dl.acm.org/citation.cfm?id=1455260},
year = {2008},
date = {2008-12-03},
journal = {In ACM Transactions on Computer Systems (TOCS)},
volume = {26},
number = {4},
abstract = {We show how to significantly improve the mean response time seen by both uploaders and downloaders in peer-to-peer data-sharing systems. Our work is motivated by the observation that response times are largely determined by the performance of the peers serving the requested objects, that is, by the peers in their capacity as servers. With this in mind, we take a close look at this server side of peers, characterizing its workload by collecting and examining an extensive set of traces. Using trace-driven simulation, we demonstrate the promise and potential problems with scheduling policies based on shortest-remaining-processing-time (SRPT), the algorithm known to be optimal for minimizing mean response time. The key challenge to using SRPT in this context is determining request service times. In addressing this challenge, we introduce two new estimators that enable predictive SRPT scheduling policies that closely approach the performance of ideal SRPT. We evaluate our approach through extensive single-server and system-level simulation coupled with real Internet deployment and experimentation.},
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We show how to significantly improve the mean response time seen by both uploaders and downloaders in peer-to-peer data-sharing systems. Our work is motivated by the observation that response times are largely determined by the performance of the peers serving the requested objects, that is, by the peers in their capacity as servers. With this in mind, we take a close look at this server side of peers, characterizing its workload by collecting and examining an extensive set of traces. Using trace-driven simulation, we demonstrate the promise and potential problems with scheduling policies based on shortest-remaining-processing-time (SRPT), the algorithm known to be optimal for minimizing mean response time. The key challenge to using SRPT in this context is determining request service times. In addressing this challenge, we introduce two new estimators that enable predictive SRPT scheduling policies that closely approach the performance of ideal SRPT. We evaluate our approach through extensive single-server and system-level simulation coupled with real Internet deployment and experimentation. |
Fabián E. Bustamante, Yi Qiao Designing Less-structured P2P Systems for the Expected High Churn Journal Article In IEEE/ACM Transactions on Networking, (ToN), 16 (3), 2008. Abstract | BibTeX | Links:  @article{DesigningLess,
title = {Designing Less-structured P2P Systems for the Expected High Churn},
author = {Fabián E. Bustamante and Yi Qiao},
url = {http://www.aqualab.cs.northwestern.edu/wp-content/uploads/2019/02/BustamanteTON07.pdf},
year = {2008},
date = {2008-06-03},
journal = {In IEEE/ACM Transactions on Networking, (ToN)},
volume = {16},
number = {3},
abstract = {We address the problem of highly transient populations in unstructured and loosely-structured peer-to-peer systems. We propose a number of illustrative query-related strategies and organizational protocols that, by taking into consideration the expected session times of peers (their lifespans), yield systems with performance characteristics more resilient to the natural instability of their environments. We first demonstrate the benefits of lifespan-based organizational protocols in terms of end-application performance and in the context of dynamic and heterogeneous Internet environments. We do this using a number of currently adopted and proposed query-related strategies, including methods for query distribution, caching and replication. We then show, through trace-driven simulation and wide-area experimentation, the performance advantages of lifespan-based, query-related strategies when layered over currently employed and lifespan-based organizational protocols. While merely illustrative, the evaluated strategies and protocols clearly demonstrate the advantages of considering peers' session time in designing widely-deployed peer-to-peer systems.},
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pubstate = {published},
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We address the problem of highly transient populations in unstructured and loosely-structured peer-to-peer systems. We propose a number of illustrative query-related strategies and organizational protocols that, by taking into consideration the expected session times of peers (their lifespans), yield systems with performance characteristics more resilient to the natural instability of their environments. We first demonstrate the benefits of lifespan-based organizational protocols in terms of end-application performance and in the context of dynamic and heterogeneous Internet environments. We do this using a number of currently adopted and proposed query-related strategies, including methods for query distribution, caching and replication. We then show, through trace-driven simulation and wide-area experimentation, the performance advantages of lifespan-based, query-related strategies when layered over currently employed and lifespan-based organizational protocols. While merely illustrative, the evaluated strategies and protocols clearly demonstrate the advantages of considering peers' session time in designing widely-deployed peer-to-peer systems. |
Yi Qiao, Dong Lu, Fabián E. Bustamante, Peter Dinda Looking at the Server-Side of Peer-to-Peer Systems Technical Report Department of Computer Science, Northwestern University ( NWU-CS-04-37), 2004. Abstract | BibTeX | Links: @techreport{SSP2PS,
title = {Looking at the Server-Side of Peer-to-Peer Systems},
author = {Yi Qiao and Dong Lu and Fabián E. Bustamante and Peter Dinda},
url = {http://typica.cs.northwestern.edu/wp-content/uploads/2019/02/NWU-CS-04-37.pdf},
year = {2004},
date = {2004-02-01},
number = { NWU-CS-04-37},
institution = {Department of Computer Science, Northwestern University},
abstract = {Peer-to-peer systems have grown significantly in popularity over the last few years. An increasing number of research projects have been closely following this trend, looking at many of the paradigm s technical aspects. In the context of data-sharing services, efforts have focused on a variety of issues from object location and routing to fair sharing and peer lifespans. Overall, the majority of these projects have concentrated on either the whole P2P infrastructure or the client-side of peers. Little attention has been given to the peer s server-side, even when that side determines much of the everyday user s experience. In this paper, we make the case for looking at the server side of peers, focusing on the problem of scheduling with the intent of minimizing the average response time experienced by users. We start by characterizing server workload based on extensive trace collection and analysis. We then evaluate the performance and fairness of different scheduling policies through trace-driven simulations. Our results show that average response time can be dramatically reduced by more effectively scheduling the requests on the server-side of P2P systems.},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
Peer-to-peer systems have grown significantly in popularity over the last few years. An increasing number of research projects have been closely following this trend, looking at many of the paradigm s technical aspects. In the context of data-sharing services, efforts have focused on a variety of issues from object location and routing to fair sharing and peer lifespans. Overall, the majority of these projects have concentrated on either the whole P2P infrastructure or the client-side of peers. Little attention has been given to the peer s server-side, even when that side determines much of the everyday user s experience. In this paper, we make the case for looking at the server side of peers, focusing on the problem of scheduling with the intent of minimizing the average response time experienced by users. We start by characterizing server workload based on extensive trace collection and analysis. We then evaluate the performance and fairness of different scheduling policies through trace-driven simulations. Our results show that average response time can be dramatically reduced by more effectively scheduling the requests on the server-side of P2P systems. |
Yi Qiao, Fabián E. Bustamante Elders Know Best: Lifespan-Based Ideas in P2P Systems Journal Article 19th Symposium on Operating Systems Principles, 2003. Abstract | BibTeX | Links:  @article{EKBLBI,
title = {Elders Know Best: Lifespan-Based Ideas in P2P Systems},
author = {Yi Qiao and Fabián E. Bustamante},
url = {http://typica.cs.northwestern.edu/wp-content/uploads/2019/02/YQiao03EKB.pdf
http://typica.cs.northwestern.edu/wp-content/uploads/2019/02/YQiao03EKB.ppt},
year = {2003},
date = {2003-10-03},
journal = {19th Symposium on Operating Systems Principles},
abstract = {The transiency of peer population and its implications on peer-to-peer (P2P) applications are increasingly calling the attention of the research community. As undesireable as unavoidable, peers transiency could negate many of the appealing features of the P2P approach.
We are exploring new P2P protocols and strategies that, by considering peers' lifespan a key attribute, can greatly boost the stability, efficiency and scalability of these systems. This work-in-progress briefly discusses our appraoch and presents some initial results.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The transiency of peer population and its implications on peer-to-peer (P2P) applications are increasingly calling the attention of the research community. As undesireable as unavoidable, peers transiency could negate many of the appealing features of the P2P approach.
We are exploring new P2P protocols and strategies that, by considering peers' lifespan a key attribute, can greatly boost the stability, efficiency and scalability of these systems. This work-in-progress briefly discusses our appraoch and presents some initial results. |
Fabián E. Bustamante, Yi Qiao Friendships that last: Peer lifespan and its role in P2P protocols Journal Article In Proc. of the International Workshop on Web Content Caching and Distribution, 2003. Abstract | BibTeX | Links: @article{PLP2PP,
title = {Friendships that last: Peer lifespan and its role in P2P protocols},
author = {Fabián E. Bustamante and Yi Qiao},
url = {http://typica.cs.northwestern.edu/wp-content/uploads/2019/02/Bustamante03FLPL.pdf
http://typica.cs.northwestern.edu/wp-content/uploads/2019/02/Bustamante03FLPL-2.ppt},
year = {2003},
date = {2003-09-03},
journal = {In Proc. of the International Workshop on Web Content Caching and Distribution},
abstract = {We consider the problem of choosing who to "befriend" among a collection of known peers in distributed P2P systems. In particular, our work explores a number of P2P protocols that, by considering peers' lifespan distribution a key attribute, can yield systems with performance characteristics more resilient to the natural instability of their environments.
This article presents results from our initial efforts, focusing on currently deployed decentralized P2P systems. We measure the observed lifespan of more than 500,000 peers in a popular P2P system for over a week and propose a functional form that fits the distribution well. We consider a number of P2P protocols based on this distribution, and use a trace-driven simulator to compare them against alternative protocols for decentralized and unstructured or loosely-structured P2P systems. We find that simple lifespan-based protocols can reduce the ratio of connection breakdowns and their associated costs by over 42%.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We consider the problem of choosing who to "befriend" among a collection of known peers in distributed P2P systems. In particular, our work explores a number of P2P protocols that, by considering peers' lifespan distribution a key attribute, can yield systems with performance characteristics more resilient to the natural instability of their environments.
This article presents results from our initial efforts, focusing on currently deployed decentralized P2P systems. We measure the observed lifespan of more than 500,000 peers in a popular P2P system for over a week and propose a functional form that fits the distribution well. We consider a number of P2P protocols based on this distribution, and use a trace-driven simulator to compare them against alternative protocols for decentralized and unstructured or loosely-structured P2P systems. We find that simple lifespan-based protocols can reduce the ratio of connection breakdowns and their associated costs by over 42%.
|
Yi Qiao, Fabián E. Bustamante The effect of lasting friendships in P2P protocols Technical Report Department of Computer Science, Northwestern University (NWU-CS-03-23 ), 2003. BibTeX @techreport{FP2PP,
title = {The effect of lasting friendships in P2P protocols},
author = {Yi Qiao and Fabián E. Bustamante},
year = {2003},
date = {2003-02-03},
number = {NWU-CS-03-23 },
institution = {Department of Computer Science, Northwestern University},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
|
