DerechoDDS: Strongly Consistent Data Distribution for Mission-Critical Applications

Mission-critical applications frequently rely on communication middleware products, enabling ease of deployment, component integration, and proven dependability. However, existing communication middleware options present limitations such as weak consistency guarantees, reflecting concerns about overheads for strong forms of assurance. The hardware landscape is now evolving: hardware-based kernel bypass technologies like Remote Direct Memory Access (RDMA) offer faster communication with near-perfect reliability. This paper introduces DerechoDDS, an implementation of the OMG Data Distribution Service (DDS) layered over Derecho, an open-source library embodying a new approach to atomic multicast that maps efficiently to RDMA (or TCP emulations of RDMA). We first describe how DerechoDDS maps the standard DDS API on the Derecho library to achieve a zero-copy data path among remote entities. Then, we propose a novel QoS policy to control the level of consistency for data distribution. We demonstrate that DerechoDDS offers comparable or substantially higher performance than today's major DDS implementations, while simultaneously strengthening guarantees. Even when configured for strong consistency, DerechoDDS achieves high performance.