Testing Raft-Replicated Database Systems

Abstract

The replication technique based on Raft protocol is essential in modern distributed and highly-available database systems. Although Raft is a protocol easy to understand and implement, testing a Raft-replicated database system is still a challenging task due to multiple sources of nondeterminism. Conventional testing techniques, such as unit, integration and stress testing, are ineffective in preventing serious but subtle bugs from reaching production. This paper first introduces evaluation metrics after the abstraction of general Raft-replicated database systems. These metrics are defined from several aspects including correctness, performance, and scalability. Then, we present test dimensions for the design of test cases, which contain various fault types, different workloads and system configurations. Finally, we describe test results of Raft-replicated open source database system.