Achieving Precise Clock Synchronization on AWS

Franck Pachot's blog post delves into the intricacies of achieving precise clock synchronization in Amazon EC2 instances, which is crucial for maintaining database consistency and performance in distributed systems like YugabyteDB. The post discusses the importance of accurate timekeeping for correct event ordering in distributed databases, where operations must be executed in sequence to maintain data integrity, as exemplified by banking transactions. It explores how traditional databases use sequential numbering systems for event ordering, whereas distributed databases face challenges due to potential clock drift across nodes. The blog highlights various time synchronization methods on AWS, notably the Network Time Protocol (NTP), AWS Time Sync Service, and the Precision Hardware Clock (PHC) introduced at AWS re:Invent 2023, which offers sub-millisecond accuracy. Furthermore, it discusses the Precision Time Protocol (PTP) for greater precision and the use of ClockBound to provide a secure time source, enabling YugabyteDB to replace its conservative 500ms clock skew setting. Overall, the post emphasizes how AWS's time synchronization innovations, particularly PHC and ClockBound, allow distributed databases to operate with enhanced precision and performance, leveraging cloud infrastructure capabilities.