Time hybrid total order broadcast: Exploiting the inherent synchrony of broadcast networks

• We give experimental evidence of the inherent synchrony exhibited by broadcast networks.
• We investigate the implications of synchrony to the design of total order broadcasts.
• We detail a novel synchronous total order protocol (THyTOB) and its implementation.
• We implement and assess a rounds protocol that serves as the substrate for THyTOB.
• THyTOB’s performance is on a par with protocols designed for purely asynchronous systems.

Total order broadcast is a fundamental communication primitive for the construction of highly-available systems. Informally, the primitive guarantees that messages sent by a group of processes are delivered to all processes in the same order. This paper investigates the design and performance of a very simple synchronous total order broadcast that is built atop of an asynchronous distributed system based on a broadcast network. Our Time Hybrid Total Order Broadcast (THyTOB) explores the inherent synchrony of the broadcast network to build a total order for the messages, while ensuring safety under asynchrony and in the presence of process failures. We assess the performance of THyTOB in an Ethernet-based commodity cluster, and show that it is on a par with the performance of other well-known, and more complex total order broadcast protocols inherently designed for the asynchronous model.