A logical clock is a mechanism for capturing chronological and causal relationships in a distributed system.
Logical clock algorithms of note are:
- Lamport timestamps, which are monotonically increasing software counters.
- Vector clocks, that allow for total ordering of events in a distributed system.
- Version vectors, order replicas, according to updates, in an optimistic replicated system.
- Matrix clocks, an extension of vector clocks that also contains information about other processes' views of the system.
Famous quotes containing the words logical and/or clock:
“Nature’s law says that the strong must prevent the weak from living, but only in a newspaper article or textbook can this be packaged into a comprehensible thought. In the soup of everyday life, in the mixture of minutia from which human relations are woven, it is not a law. It is a logical incongruity when both strong and weak fall victim to their mutual relations, unconsciously subservient to some unknown guiding power that stands outside of life, irrelevant to man.”
—Anton Pavlovich Chekhov (1860–1904)
“We all run on two clocks. One is the outside clock, which ticks away our decades and brings us ceaselessly to the dry season. The other is the inside clock, where you are your own timekeeper and determine your own chronology, your own internal weather and your own rate of living. Sometimes the inner clock runs itself out long before the outer one, and you see a dead man going through the motions of living.”
—Max Lerner (b. 1902)