Toggle Main Menu Toggle Search

Open Access padlockePrints

Improving ZooKeeper Atomic Broadcast Performance by Coin Tossing

Lookup NU author(s): Ibrahim El-sanosi, Dr Paul EzhilchelvanORCiD


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


ZooKeeper atomic broadcast (Zab) is at the core of ZooKeeper system, enforcinga total order on service requests that seek to modify the replicated service state.Since it is a leader based protocol, its performance degradeswhen the leader server is made to handle an increased message traffic.We address this concern by having the other, non-leader server replicas toss a coin andbroadcast their acknowledgement of a leader's proposalonly if the toss results in an outcome of Head.We model the coin-tossing process and derive analytical expressionsfor estimating the coin's probability of Head for a given arrival rate of service requestssuch that the dual objectives ofperformance gains and traffic reduction can be accomplished.Experiments compare the performance of our coin-tossing Zab version (ZabCT)with Zab performanceand confirm that the dual objectives are demonstrably met under heavy workloads.Moreover, ZabCT meets all requirementsessential for crash-tolerance provisions within Zab which can therefore beadopted in any ZabCT implementation.

Publication metadata

Author(s): El-Sanosi I, Ezhilchelvan P

Editor(s): Reinecke, P; DiMarco, A;

Publication type: Conference Proceedings (inc. Abstract)

Publication status: Published

Conference Name: Computer Performance Engineering (EPEW 2017)

Year of Conference: 2017

Pages: 249-265

Print publication date: 07/09/2017

Acceptance date: 29/06/2017

ISSN: 9783319665832

Publisher: Springer


DOI: 10.1007/978-3-319-66583-2_16

Notes: It describes a novel design that seeks to improve the performance of Zookeeper - a leader based coordination protocol - by reducing message traffic at the leader, both inbound and outbound. Experiments confirm that adaptive estimation of coin-toss probabilities increase coordination latency considerably, particularly when the load on the system is high.

Series Title: Lecture Notes in Computer Science