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:
“Grammar is a tricky, inconsistent thing. Being the backbone of speech and writing, it should, we think, be eminently logical, make perfect sense, like the human skeleton. But, of course, the skeleton is arbitrary, too. Why twelve pairs of ribs rather than eleven or thirteen? Why thirty-two teeth? It has something to do with evolution and functionalism—but only sometimes, not always. So there are aspects of grammar that make good, logical sense, and others that do not.”
—John Simon (b. 1925)
“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)