Time and Clocks Summary

Time and Clocks Summary

Summary and comparison of time synchronization approaches.

| Clock Type | Tracks Real Time | Orders Events | Detects Concurrency | | -------------- | ---------------- | ------------- | ------------------- | | Physical Clock | Yes | No | No | | Lamport Clock | No | Yes | No | | Vector Clock | No | Yes | Yes |

Confusion: -> physical Clock - hardware clock -> current_time = now() -> Lamport Clock and Vector Clock we do it manually. by maintaing variables in our code -> Vector Clocks are used in Cassandra (early version), Amazon Dynamo -> Conflict-free Replicated Data Type (Google Docs) please study