This is an example of a system built like you're describing at the end: https://www.pingcap.com/blog/how-an-open-source-distributed-newsql-database-delivers-tim

This is an example of a system built like you're describing at the end: https://www.pingcap.com/blog/how-an-open-source-distributed-newsql-database-delivers-time-services/ https://www.pingcap.com/blog/how-an-open-source-distributed-... Also see https://tikv.org/deep-dive/distributed-transaction/timestamp-oracle/ https://tikv.org/deep-dive/distributed-transaction/timestamp... Cockroachdb describes their approach here: https://www.cockroachlabs.com/blog/living-without-atomic-clocks/ https://www.cockroachlabs.com/blog/living-without-atomic-clo...