Title :
Analyzing dynamic voting using Petri nets
Author :
Chen, Ing-Ray ; Wang, Ding-Chau
Author_Institution :
Inst. of Inf. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
Abstract :
Dynamic voting is considered a promising technique for achieving high availability in distributed systems with data replication. To date, stochastic analysis of dynamic voting algorithms is restricted to either site or link Markov models, but not both, possibly because of the difficulty in specifying the state-space which grows exponentially as the number of sites increases. Furthermore, to reduce the state-space, the assumption of “frequent updates” was normally made, which results in an overestimation of the availability. In this paper, we develop a Petri net model that considers both site and link failures and also relaxes the modeling assumption of frequent updates. We test our Petri net model on ring and star network topologies to analyze if availability under dynamic voting can be seriously degraded if updates are not frequent under various site and link failure/repair situations. Finally, We use the Petri net developed in the paper to determine the maximum achievable improvement in availability when null updates are introduced to augment regular updates to keep the status of availability up-to-date
Keywords :
Petri nets; distributed databases; replicated databases; software reliability; Petri net model; Petri nets; availability; data replication; distributed systems; dynamic voting; high availability; maximum achievable improvement; Algorithm design and analysis; Availability; Degradation; Failure analysis; Heuristic algorithms; Network topology; Petri nets; Stochastic processes; Testing; Voting;
Conference_Titel :
Reliable Distributed Systems, 1996. Proceedings., 15th Symposium on
Conference_Location :
Nigara-on-the-Lake, Ont.
Print_ISBN :
0-8186-7481-4
DOI :
10.1109/RELDIS.1996.559695