A Self-Stabilizing Communication Primitive

Parallel Processing Letters, 2008

We provide self-stabilizing algorithms to obtain and maintain a maximal matching, maximal independent set or minimal dominating set in a given system graph. They converge in linear rounds under a distributed or synchronous daemon. They can be implemented in an ad hoc network by piggy-backing on the beacon messages that nodes already use.

Dijkstra: it is the property f o r a system t o eventually recover by itself a legitimate state after any perturbation modifying the m e m o r y state. This paper proposes a dynamic automatic selfstabilizing protocol. This algorithm runs i n the fully asynchronous message-passing model in which messages can also be corrupted. The principle of the algorithm is t o compute regularly a global state and if necessary t o generate a global reset. W h e n the system is stabilized, the message complexity is O(max(6 * m,n2)) where 6 is the degree of the communication graph, m the number of links and n the number of processus. This complexity allows a possable implementation.

Journal of Computer and System Sciences, 2010

This paper presents a shared-memory self-stabilizing failure detector, asynchronous consensus and replicated state-machine algorithm suite, the components of which can be started in an arbitrary state and converge to act as a virtual state-machine. Self-stabilizing algorithms can cope with transient faults. Transient faults can alter the system state to an arbitrary state and hence, cause a temporary violation of the safety property of the consensus. Started in an arbitrary state, the long lived, memory bounded and self- ...

SIAM Journal on Computing, 1997

Self-stabilizing message driven protocols are de ned and discussed. The class weakexclusion that contains many natural tasks such as `-exclusion and token-passing is dened, and it is shown that in any execution of any self-stabilizing protocol for a task in this class, the con guration size must grow at least in a logarithmic rate. This last lower bound is valid even if the system is supported by a time-out mechanism that prevents communication deadlocks. Then we present three self-stabilizing message driven protocols for token-passing. The rate of growth of con guration size for all three protocols matches the aforementioned lower bound. Our protocols are presented for two processor systems but can be easily adapted to rings of arbitrary size. Our results have an interesting interpretation in terms of automata theory.

ArXiv, 2018

We study the problem of privately emulating shared memory in message-passing networks. The system includes clients that store and retrieve replicated information on N servers, out of which e are malicious. When a client access a malicious server, the data field of that server response might be different than the value it originally stored. However, all other control variables in the server reply and protocol actions are according to the server algorithm. For the coded atomic storage (CAS) algorithms by Cadambe et al., we present an enhancement that ensures no information leakage and malicious fault-tolerance. We also consider recovery after the occurrence of transient faults that violate the assumptions according to which the system is to behave. After their last occurrence, transient faults leave the system in an arbitrary state (while the program code stays intact). We present a self-stabilizing algorithm, which recovers after the occurrence of transient faults. This addition to C...

2005

Awareness of the need for robustness in distributed systems increases as distributed systems become integral parts of day-to-day systems. Self-stabilizing while tolerating ongoing Byzantine faults are wishful properties of a distributed system. Many distributed tasks (e.g. clock synchronization) possess ecient non-stabilizing solutions tolerating Byzantine faults or conversely non-Byzantine but self-stabilizing solutions. In contrast, designing algorithms that self-stabilize while at the same time tolerating an eventual fraction of permanent Byzantine failures present a special challenge due to the ambition of malicious nodes to hamper stabilization if the systems tries to recover from a corrupted state. This diculty might be indicated by the remarkably few algorithms that are resilient to both fault models. We present the rst scheme that takes a Byzantine distributed algorithm and produces its self-stabilizing Byzantine counterpart, while having a relatively low overhead of O(f ) communication rounds, where f is the number of actual faults. Our protocol is based on a tight Byzantine self-stabilizing pulse synchronization procedure. The synchronized pulses are used as events for initializing Byzantine agreement on every node's local state. The set of local states is used for global predicate detection. Should the global state represent an illegal system state then the target algorithm is reset.

2009 29th IEEE International Conference on Distributed Computing Systems, 2009

Self-stabilization is a general paradigm to provide forward recovery capabilities to distributed systems and networks. Intuitively, a protocol is selfstabilizing if it is able to recover without external intervention from any catastrophic transient failure. In this paper, our focus is to lower the communication complexity of self-stabilizing protocols below the need of checking every neighbor forever. In more details, the contribution of the paper is threefold: (i) We provide new complexity measures for communication efficiency of self-stabilizing protocols, especially in the stabilized phase or when there are no faults, (ii) On the negative side, we show that for non-trivial problems such as coloring, maximal matching, and maximal independent set, it is impossible to get (deterministic or probabilistic) self-stabilizing solutions where every participant communicates with less than every neighbor in the stabilized phase, and (iii) On the positive side, we present protocols for coloring, maximal matching, and maximal independent set such that a fraction of the participants communicates with exactly one neighbor in the stabilized phase.