An Evaluation of Efficient Leader Election Algorithms for Crash-Recovery Systems

Abstract

This paper presents an evaluation of three communication-efficient algorithms implementing the Omega class of failure detectors, which provides an eventual leader election functionality, in distributed systems where processes can crash and recover. Communication efficiency means that eventually only a correct process, i.e., the elected leader, keeps sending a message periodically to the rest of processes. The first algorithm relies on the use of stable storage to store the identity of the leader and an incarnation number. The second algorithm does not use stable storage, but requires a majority of correct processes. Also, it is near-communication-efficient, since besides the leader, unstable processes, i.e., those that crash and recover infinitely often, may send messages periodically before they receive a message from the leader. Finally, the third algorithm does neither use stable storage nor require a majority of correct processes, but assumes that each process has access to a nondecreasing and persistent local clock. Using the OMNeT++ network simulation framework, we evaluate the performance and the quality of service provided by these algorithms, in terms of the number of messages exchanged among processes and the capability of the failure detector to provide a single leader, respectively.