Clocks and Causality – Ordering Events in Distributed Systems (2022)
> However, because of clock drifts and/or assumptions around network time delays, timestamps from conventional clocks are not always mutually comparable, and therefore events cannot be reliably ordered using timestamps from conventional clocks.<p>This isn’t quite right. CockroachDB and Yuggabyte both use conventional clocks to reliably order events. Spanner uses GPS to do so (conventional time stamp but maybe not technically a conventional clock).