Verification of Randomized Distributed Algorithms under Round-Rigid Adversaries

Abstract : Randomized fault-tolerant distributed algorithms pose a number of challenges for automated verification: (i) parameterization in the number of processes and faults, (ii) randomized choices and probabilistic properties, and (iii) an unbounded number of asynchronous rounds. The combination of these challenges makes verification hard. Challenge (i) was recently addressed in the framework of threshold automata. We extend threshold automata to model randomized algorithms that perform an unbounded number of asynchronous rounds. For non-probabilistic properties, we show that it is necessary and sufficient to verify these properties under round-rigid schedules, that is, schedules where no process enters round r before all other processes finished round r −1. For almost-sure termination, we analyze these algorithms under round-rigid adversaries , that is, fair adversaries that only generate round-rigid schedules. This allows us to do compositional and inductive reasoning that reduces verification of the asynchronous multi-round algorithms to model checking of a one-round threshold automaton. We apply this framework to classic algorithms: Ben-Or's and Bracha's seminal consensus algorithms for crashes and Byzantine faults, 2-set agreement for crash faults, and RS-Bosco for the Byzantine case.
Type de document :
Pré-publication, Document de travail
Experiments presented in this paper were carried out using the Grid5000 testbed, supported by a s.. 2018
Liste complète des métadonnées

https://hal.inria.fr/hal-01925533
Contributeur : Nathalie Bertrand <>
Soumis le : lundi 19 novembre 2018 - 10:06:24
Dernière modification le : mercredi 21 novembre 2018 - 01:12:37

Fichier

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

Identifiants

  • HAL Id : hal-01925533, version 2

Citation

Nathalie Bertrand, Igor Konnov, Marijana Lazic, Josef Widder. Verification of Randomized Distributed Algorithms under Round-Rigid Adversaries. Experiments presented in this paper were carried out using the Grid5000 testbed, supported by a s.. 2018. 〈hal-01925533v2〉

Partager

Métriques

Consultations de la notice

60

Téléchargements de fichiers

35