Jump to content

Logical clock

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by CesarB (talk | contribs) at 01:58, 4 February 2006 (wikify Lamport logical clock). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

A logical clock is a mechanism for capturing chronological and causal relationships in a distributed system. As physical clocks cannot be perfectly synchronized, event timestamps derived from readings of physical clocks cannot in general be used to find out the order in which events happened.

Logical clock algorithms of note are:

  • Lamport logical clocks, which is a monotonically increasing software counters
  • Vector clocks, that allow for total ordering of events in a distributed system.
  • Matrix clocks, an extension of vector clocks that also contains information about other processes' views of the system.