Living Without Atomic Clocks

The design of CockroachDB is based on Google’s Spanner data storage system. One of the most surprising and inspired facets of Spanner is its use of atomic clocks and GPS clocks to give participating nodes really accurate wall time synchronization. The designers of Spanner call this “TrueTime”, and it provides a tight bound on clock offset between any two nodes […]

The design of CockroachDB is based on Google’s Spanner data storage system. One of the most surprising and inspired facets of Spanner is its use of atomic clocks and GPS clocks to give participating nodes really accurate wall time synchronization. The designers of Spanner call this “TrueTime”, and it provides a tight bound on clock offset between any two nodes in the system. This lets them do pretty nifty things! We’ll elaborate on a few of these below, but chief among them is their ability to leverage tightly synchronized clocks to provide a high level of external consistency (we’ll explain what this is).
Source: CockroachDB