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Lecture #15 Distributed Algorithms (III). CS492 Special Topics in Computer Science: Distributed Algorithms and Systems. Admin Stuff. Next week Team #1 at 9:00am on Tue Team #2 at 9:45am on Tue Team #3 at ??? on Tue Team #4 at ??? on Tue Additional meeting on demand on Fri 10am-3pm
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Lecture #15Distributed Algorithms (III) CS492 Special Topics in Computer Science: Distributed Algorithms and Systems
Admin Stuff • Next week • Team #1 at 9:00am on Tue • Team #2 at 9:45am on Tue • Team #3 at ??? on Tue • Team #4 at ??? on Tue • Additional meeting on demand on Fri 10am-3pm • Expected deliverables • Steady progress from last week • Concrete execution plan
Key Idea Trajectories of successive tokens originating at process i in teh HS algorithm
Complexity Analysis p34 bottom
What if we don’t use comparison? • The TimeSlice algorithm • ring size n is known • unidirectional communication • idea: elect the process with minimum UID • “non-arrival” very meaningful • time complexity? • message complexity?
What if ring size is unknown? While keeping message complexity of O(n) Can we do it? How about time complexity? VariableSpeeds algorithms
Now the question is: Is O (n log n) the lower bound for comparison-based algorithms?
Next question is: What is the lower bound for non-comparison-based algorithms? Is it possible to show that this can only happen at the cost of large time complexity?