A Topological Treatment of Early-Deciding Set-Agreement

This paper considers the k-set-agreement problem in a synchronous message passing distributed system where up to t processes can fail by crashing. We determine the number of communication rounds needed for all correct processes to reach a decision in a given run, as a function of k, the degree of coordination, and f <= t the number of processes that actually fail in the run. We prove a lower bound of min(\floor{f/k}+2,\floor{t/k}+1) rounds. Our proof uses simple topological tools to reason about runs of a full information set-agreement protocol. In particular, we introduce a new topological operator, which we call the early deciding operator, to capture rounds where k processes fail but correct processes see only k-1 failures.

Published in:
Proceedings of the 10th International Conference On Principles Of Distributed Systems (OPODIS '06)
Presented at:
OPODIS 2006, Bordeaux, France, December 12-15, 2006

 Record created 2006-10-05, last modified 2018-03-17

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