Of Choices, Failures and Asynchrony: The Many Faces of Set Agreement

Abstract : Set agreement is a fundamental problem in distributed com- puting in which processes collectively choose a small subset of values from a larger set of proposals. The impossibility of fault-tolerant set agreement in asynchronous networks is one of the seminal results in distributed computing. The complexity of set agreement in synchronous networks has also been a significant research challenge. Real systems, however, are neither purely synchronous nor purely asynchronous. Rather, they tend to alternate between periods of synchrony and periods of asynchrony. In this paper, we analyze the complexity of set agreement in a such a "partially synchronous" setting, presenting the first (asymptotically) tight bound on the complexity of set agreement in such systems. We introduce a novel technique for simulating, in fault-prone asynchronous shared memory, executions of an asynchronous and failure-prone message- passing system in which some fragments appear synchronous to some processes. We use this technique to derive a lower bound on the round complexity of set agreement in a partially synchronous system by a reduction from asynchronous wait-free set agreement. We also present an asymptotically matching algorithm that relies on a distributed asyn- chrony detection mechanism to decide as soon as possible during periods of synchrony. By relating environments with differing degrees of synchrony, our simu- lation technique is of independent interest. In particular, it allows us to obtain a new lower bound on the complexity of early deciding k-set agree- ment complementary to that of [12], and to re-derive the combinatorial topology lower bound of [13] in an algorithmic way.
Type de document :
Communication dans un congrès
Yingfei Dong and Ding-Zhu Du and Oscar H. Ibarra. ISAAC, 2009, Unknown, Springer, 5878, pp.943-953, 2009, Lecture Notes in Computer Science
Liste complète des métadonnées

Littérature citée [18 références]  Voir  Masquer  Télécharger

https://hal.inria.fr/hal-00992777
Contributeur : Corentin Travers <>
Soumis le : lundi 19 mai 2014 - 11:51:06
Dernière modification le : mercredi 16 mai 2018 - 11:23:13
Document(s) archivé(s) le : lundi 10 avril 2017 - 23:42:46

Fichier

7.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

  • HAL Id : hal-00992777, version 1

Citation

Dan Alistarh, Seth Gilbert, Rachid Guerraoui, Corentin Travers. Of Choices, Failures and Asynchrony: The Many Faces of Set Agreement. Yingfei Dong and Ding-Zhu Du and Oscar H. Ibarra. ISAAC, 2009, Unknown, Springer, 5878, pp.943-953, 2009, Lecture Notes in Computer Science. 〈hal-00992777〉

Partager

Métriques

Consultations de la notice

378

Téléchargements de fichiers

76