Hybridtime

HybridTime introduces a hybrid between physical and logical clocks that can be used to implement globally consistent database snapshots. HybridTime is one implementation of the general concept of Hybrid Logical Clocks that combine the logical clock semantics of Lamport and Vector clocks with a physical representation of time such as Spanner’s TrueTime. HybridTime follows similar update semantics as Lamport and Vector Clocks, where each node in the system updates their internal clock in response to events received. It differs in that HybridTime values are not purely logical — they include a physical time component that allows values to be associated with a physical point-in-time. ...