Revisiting Time, Clocks, and Synchronization

TL;DR

This paper reviews existing clock synchronization methods, highlights their limitations, and proposes exploring independent time network approaches for achieving low-cost, high-precision synchronization in computer systems.

Contribution

It provides a comprehensive review of current synchronization techniques and discusses potential improvements and alternative approaches for better precision and cost-effectiveness.

Findings

White Rabbit achieves sub-nanosecond synchronization

Existing systems like Spanner and Sundial have limitations

Independent time network approaches offer promising future directions

Abstract

Sub-nanosecond precision clock synchronization over the packet network has been achieved by the White Rabbit protocol for a decade. However, few computer systems utilize such a technique. We try to attract more interest in the clock synchronization problem. We first introduce the basics of clock and synchronization in the time and frequency discipline. Then we revisit several related works, such as Google's Spanner, Huygens, FARMv2, DTP, and Sundial, explain why these works could be improved. Finally, we briefly discuss an independent time network approach towards low-cost and high-precision synchronization.