Course: Distributed operating systems

Time, Synchronisation and Coordination in Distributed Systems

Time and Clocks

• Time and its Representation
  Time
  Real Time
  Clock time
  Ideal clock
  Real Clock
• Events, States and Intervals
  Intervals in Real Time
  Intervals in Clock Time
  Events, States and Temporal Intervals
• Event Ordering
  Casual (or happened-before) ordering
  Global (or total) ordering
  Sync (or casual-global) ordering
• Clocks in Real-Time Systems
  Physical clock
  Logical clock (or Lamport’s clock)
  Vector clock

• Centralised Co-ordination
• Cristian’s algorithm
  Berkeley algorithm

• Centralised Co-ordination
  Central process or server
  Eventcounts
  Static sequencer
• Distributed Coordination
  Multiple physical clocks
  Multiple logical clocks
• Election
  The Bully algorithm for election
  Ring algorithm for election