Hardening Cassandra Against Byzantine Failures

TL;DR

This paper analyzes Cassandra's vulnerabilities to Byzantine failures and proposes protocols to enhance its robustness, supported by empirical performance evaluations using YCSB benchmark.

Contribution

It introduces new protocols for Byzantine fault tolerance in Cassandra, combining cryptographic and algorithmic solutions with empirical performance analysis.

Findings

Protocols improve Cassandra's resilience to Byzantine failures

Cryptographic adjustments have acceptable performance overhead

Empirical results demonstrate feasibility of the proposed solutions

Abstract

Cassandra is one of the most widely used distributed data stores these days. Cassandra supports flexible consistency guarantees over a wide-column data access model and provides almost linear scale-out performance. This enables application developers to tailor the performance and availability of Cassandra to their exact application's needs and required semantics. Yet, Cassandra is designed to withstand benign failures, and cannot cope with most forms of Byzantine attacks. In this work, we present an analysis of Cassandra's vulnerabilities and propose protocols for hardening Cassandra against Byzantine failures. We examine several alternative design choices and compare between them both qualitatively and empirically by using the Yahoo! Cloud Serving Benchmark (YCSB) performance benchmark. We include incremental performance analysis for our algorithmic and cryptographic adjustments, supporting our design choices.