7 research outputs found
A Dual Digraph Approach for Leaderless Atomic Broadcast (Extended Version)
Many distributed systems work on a common shared state; in such systems,
distributed agreement is necessary for consistency. With an increasing number
of servers, these systems become more susceptible to single-server failures,
increasing the relevance of fault-tolerance. Atomic broadcast enables
fault-tolerant distributed agreement, yet it is costly to solve. Most practical
algorithms entail linear work per broadcast message. AllConcur -- a leaderless
approach -- reduces the work, by connecting the servers via a sparse resilient
overlay network; yet, this resiliency entails redundancy, limiting the
reduction of work. In this paper, we propose AllConcur+, an atomic broadcast
algorithm that lifts this limitation: During intervals with no failures, it
achieves minimal work by using a redundancy-free overlay network. When failures
do occur, it automatically recovers by switching to a resilient overlay
network. In our performance evaluation of non-failure scenarios, AllConcur+
achieves comparable throughput to AllGather -- a non-fault-tolerant distributed
agreement algorithm -- and outperforms AllConcur, LCR and Libpaxos both in
terms of throughput and latency. Furthermore, our evaluation of failure
scenarios shows that AllConcur+'s expected performance is robust with regard to
occasional failures. Thus, for realistic use cases, leveraging redundancy-free
distributed agreement during intervals with no failures improves performance
significantly.Comment: Overview: 24 pages, 6 sections, 3 appendices, 8 figures, 3 tables.
Modifications from previous version: extended the evaluation of AllConcur+
with a simulation of a multiple datacenters deploymen