CassandrEAS: Highly Available and Storage-Efficient Distributed Key-Value Store with Erasure Coding

In this work, we propose an erasure coding-based protocol that implements a key-value store with atomicity and near-optimal storage cost. Our protocol supports concurrent read and write operations while tolerating asynchronous communication and crash failures of any client and some fraction of servers. One novel feature is a tunable knob between the number of supported concurrent operations, availability, and storage cost. We implement our protocol into Cassandra, namely Cassan-drEAS (Cassandra + Erasure-coding Atomic Storage). Extensive evaluation using YCSB on Google Cloud Platform shows that CassandrEAS incurs moderate penalty on latency and throughput, yet saves significant amount of storage space.