Booting clock synchronization in partially synchronous systems with hybrid process and link failures

摘要

This paper provides description and analysis of a new clock synchronization algorithm for synchronous and partially synchronous systems with unknown upper and lower bounds on delays. It is purely message-driven, timer-free and relies on a hybrid failure model incorporating both process and link failures, in both time and value domain. Unlike existing solutions, our algorithm works during both system start-up and normal operation: Whereas bounded precision (the mutual deviation of any two clocks) can always be guaranteed, accuracy (clocks being within a linear envelope of real-time) and hence progress is only ensured when sufficiently many correct processes are eventually up and running. By means of a detailed analysis, we provide formulas for resilience, precision and envelope bounds.