@article{378,
abstract = {The Chord peer-to-peer system is considered, together with CAN, Tapestry and Pastry, as one of the pioneering works on peer-to-peer distributed hash tables (DHT) that inspired a large volume of papers and projects on DHTs as well as peer-to-peer systems in general. Chord, in particular, has been studied thoroughly, and many variants of Chord have been presented that optimize various criteria. Also, several implementations of Chord are available on various platforms. Though Chord is known to be very efficient and scalable and it can handle churn quite well, no protocol is known yet that guarantees that Chord is self-stabilizing, i.e., the Chord network can be recovered from any initial state in which the network is still weakly connected. This is not too surprising since it is known that the Chord network is not locally checkable for its current topology. We present a slight extension of the Chord network, called Re-Chord (reactive Chord), that turns out to be locally checkable, and we present a self-stabilizing distributed protocol for it that can recover the Re-Chord network from any initial state, in which the n peers are weakly connected, in O(nlogn) communication rounds. We also show that our protocol allows a new peer to join or an old peer to leave an already stable Re-Chord network so that within O(logn)^2) communication rounds the Re-Chord network is stable again.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
journal = {Theory of Computing Systems},
number = {3},
pages = {591--612},
publisher = {Springer},
title = {{Re-Chord: A Self-stabilizing Chord Overlay Network}},
doi = {10.1007/s00224-012-9431-2},
year = {2014},
}
@inproceedings{393,
abstract = {A fundamental problem for peer-to-peer systems is to maintain connectivity while nodes are leaving, i.e., the nodes requesting to leave the peer-to-peer system are excluded from the overlay network without affecting its connectivity. There are a number of studies for safe node exclusion if the overlay is in a well-defined state initially. Surprisingly, the problem is not formally studied yet for the case in which the overlay network is in an arbitrary initial state, i.e., when looking for a self-stabilizing solution for excluding leaving nodes. We study this problem in two variants: the Finite Departure Problem (FDP) ) and the Finite Sleep Problem (FSP). In the FDP the leaving nodes have to irrevocably decide when it is safe to leave the network, whereas in the FSP, this leaving decision does not have to be final: the nodes may resume computation if necessary. We show that there is no self-stabilizing distributed algorithm for the FDP, even in a synchronous message passing model. To allow a solution, we introduce an oracle called NIDEC and show that it is sufficient even for the asynchronous message passing model by proposing an algorithm that can solve the FDP using NIDEC. We also show that a solution to the FSP does not require an oracle.},
author = {Foreback, Dianne and Koutsopoulos, Andreas and Nesterenko, Mikhail and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 16th International Symposium on Stabilization, Safety, and Security of Distributed Systems},
pages = {48----62},
title = {{On Stabilizing Departures in Overlay Networks}},
doi = {10.1007/978-3-319-11764-5_4},
year = {2014},
}
@article{387,
abstract = {This article studies the design of medium access control (MAC) protocols for wireless networks that are provably robust against arbitrary and unpredictable disruptions (e.g., due to unintentional external interference from co-existing networks or due to jamming). We consider a wireless network consisting of a set of n honest and reliable nodes within transmission (and interference) range of each other, and we model the external disruptions with a powerful adaptive adversary. This adversary may know the protocol and its entire history and can use this knowledge to jam the wireless channel at will at any time. It is allowed to jam a (1 − )-fraction of the timesteps, for an arbitrary constant > 0 unknown to the nodes. The nodes cannot distinguish between the adversarial jamming or a collision of two or more messages that are sent at the same time. We demonstrate, for the first time, that there is a local-control MAC protocol requiring only very limited knowledge about the adversary and the network that achieves a constant (asymptotically optimal) throughput for the nonjammed time periods under any of the aforementioned adversarial strategies. The derived principles are also useful to build robust applications on top of the MAC layer, and we present an exemplary study for leader election, one of the most fundamental tasks in distributed computing.},
author = {Awerbuch, Baruch and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {Transactions on Algorithms},
number = {4},
publisher = {ACM},
title = {{Principles of Robust Medium Access and an Application to Leader Election}},
doi = {10.1145/2635818},
year = {2014},
}
@article{464,
abstract = {Topological self-stabilization is an important concept to build robust open distributed systems (such as peer-to-peer systems) where nodes can organize themselves into meaningful network topologies. The goal is to devise distributed algorithms where nodes forward, insert, and delete links to neighboring nodes, and that converge quickly to such a desirable topology, independently of the initial network configuration. This article proposes a new model to study the parallel convergence time. Our model sheds light on the achievable parallelism by avoiding bottlenecks of existing models that can yield a distorted picture. As a case study, we consider local graph linearization—i.e., how to build a sorted list of the nodes of a connected graph in a distributed and self-stabilizing manner. In order to study the main structure and properties of our model, we propose two variants of a most simple local linearization algorithm. For each of these variants, we present analyses of the worst-case and bestcase parallel time complexities, as well as the performance under a greedy selection of the actions to be executed. It turns out that the analysis is non-trivial despite the simple setting, and to complement our formal insights we report on our experiments which indicate that the runtimes may be better in the average case.},
author = {Gall, Dominik and Jacob, Riko and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Täubig, Hanjo },
journal = {Theory of Computing Systems},
number = {1},
pages = {110--135},
publisher = {Springer},
title = {{A Note on the Parallel Runtime of Self-Stabilizing Graph Linearization}},
doi = {10.1007/s00224-013-9504-x},
year = {2014},
}
@article{1868,
author = {W. Richa, Andr{\'{e}}a and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {Distributed Computing},
number = {3},
pages = {159----171},
title = {{Competitive throughput in multi-hop wireless networks despite adaptive jamming}},
doi = {10.1007/s00446-012-0180-x},
year = {2013},
}
@article{1870,
author = {Mohd Nor, Rizal and Nesterenko, Mikhail and Scheideler, Christian},
journal = {Theor. Comput. Sci.},
pages = {119----129},
title = {{Corona: A stabilizing deterministic message-passing skip list}},
doi = {10.1016/j.tcs.2012.08.029},
year = {2013},
}
@inproceedings{542,
abstract = {We consider the problem of managing a dynamic heterogeneous storagesystem in a distributed way so that the amount of data assigned to a hostin that system is related to its capacity. Two central problems have to be solvedfor this: (1) organizing the hosts in an overlay network with low degree and diameterso that one can efficiently check the correct distribution of the data androute between any two hosts, and (2) distributing the data among the hosts so thatthe distribution respects the capacities of the hosts and can easily be adapted asthe set of hosts or their capacities change. We present distributed protocols forthese problems that are self-stabilizing and that do not need any global knowledgeabout the system such as the number of nodes or the overall capacity of thesystem. Prior to this work no solution was known satisfying these properties.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
booktitle = {Proceedings of the 27th International Symposium on Distributed Computing (DISC)},
pages = {537--549},
title = {{CONE-DHT: A distributed self-stabilizing algorithm for a heterogeneous storage system}},
doi = {10.1007/978-3-642-41527-2_37},
year = {2013},
}
@article{1871,
author = {W. Richa, Andrea and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {IEEE/ACM Trans. Netw.},
number = {3},
pages = {760----771},
title = {{An Efficient and Fair MAC Protocol Robust to Reactive Interference}},
doi = {10.1109/TNET.2012.2210241},
year = {2013},
}
@inproceedings{513,
abstract = {This paper initiates the study of self-adjusting networks (or distributed data structures) whose topologies dynamically adapt to a communication pattern $\sigma$. We present a fully decentralized self-adjusting solution called SplayNet. A SplayNet is a distributed generalization of the classic splay tree concept. It ensures short paths (which can be found using local-greedy routing) between communication partners while minimizing topological rearrangements. We derive an upper bound for the amortized communication cost of a SplayNet based on empirical entropies of $\sigma$, and show that SplayNets have several interesting convergence properties. For instance, SplayNets features a provable online optimality under special requests scenarios. We also investigate the optimal static network and prove different lower bounds for the average communication cost based on graph cuts and on the empirical entropy of the communication pattern $\sigma$. From these lower bounds it follows, e.g., that SplayNets are optimal in scenarios where the requests follow a product distribution as well. Finally, this paper shows that in contrast to the Minimum Linear Arrangement problem which is generally NP-hard, the optimal static tree network can be computed in polynomial time for any guest graph, despite the exponentially large graph family. We complement our formal analysis with a small simulation study on a Facebook graph.},
author = {Avin, Chen and Häupler, Bernhard and Lotker, Zvi and Scheideler, Christian and Schmid, Stefan},
booktitle = {Proceedings of the 27th IEEE International Parallel and Distributed Processing Symposium (IPDPS)},
pages = {395--406},
title = {{Locally Self-Adjusting Tree Networks}},
doi = {10.1109/IPDPS.2013.40},
year = {2013},
}
@inproceedings{519,
abstract = {In this work we present the first scalable distributed information system,i.e., a system with low storage overhead, that is provably robust againstDenial-of-Service (DoS) attacks by a current insider. We allow acurrent insider to have complete knowledge about the information systemand to have the power to block any \epsilon-fraction of its serversby a DoS-attack, where \epsilon can be chosen up to a constant. The taskof the system is to serve any collection of lookup requests with at most oneper non-blocked server in an efficient way despite this attack. Previously,scalable solutions were only known for DoS-attacks of past insiders, where apast insider only has complete knowledge about some past time pointt_0 of the information system. Scheideler et al. (DISC 2007, SPAA 2009) showedthat in this case it is possible to design an information system so that anyinformation that was inserted or last updated after t_0 is safe against a DoS-attack. But their constructions would not work at all for a current insider. The key idea behindour IRIS system is to make extensive use of coding. More precisely, we presenttwo alternative distributed coding strategies with an at most logarithmicstorage overhead that can handle up to a constant fraction of blocked servers.},
author = {Eikel, Martina and Scheideler, Christian},
booktitle = {Proceedings of the 25th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
pages = {119--129},
title = {{IRIS: A Robust Information System Against Insider DoS-Attacks}},
doi = {10.1145/2486159.2486186},
year = {2013},
}