Living Without Atomic Clocks | Where CockroachDB & Spanner Diverge

The text discusses the importance of time synchronization in distributed systems, specifically focusing on Google's Spanner and CockroachDB. It explains how TrueTime provides linearizability for Spanner by using atomic clocks and GPS clocks to give participating nodes really accurate wall time synchronization. In contrast, CockroachDB is designed to be run on off-the-shelf commodity hardware without the need for specialized clock synchronization hardware. The text also delves into concepts such as linearizability, serializability, and causal reverse, explaining how these are managed in both systems. It concludes by highlighting that while Spanner always waits after writes, CockroachDB sometimes delays reads to handle clock-related issues.