TrueTime
TrueTime is a distributed clock synchronization service developed by Google that provides globally consistent time across data centers. It exposes a clock API that returns a time interval (earliest, latest) guaranteed to contain the actual current time, accounting for uncertainty due to network delays and clock drift. This enables distributed systems to achieve strong consistency without relying on perfectly synchronized clocks.
Developers should learn TrueTime when building globally distributed applications that require strict ordering of events, such as financial transactions, distributed databases (like Spanner), or coordination services. It solves the fundamental challenge of clock synchronization in distributed systems, allowing for operations like globally consistent reads and writes without complex consensus protocols for every timestamp.