On Using Raft Over Networks: Improving Leader Election

【Author】 Choumas, Kostas; Korakis, Thanasis

【Source】IEEE TRANSACTIONS ON NETWORK AND SERVICE MANAGEMENT

【影响因子】4.758

【Abstract】Raft is a state-of-the-art consensus algorithm for state replication over a distributed system of nodes. According to Raft, all state updates occurring anywhere in the system are forwarded to the leader, which is elected among the system nodes to collect and replicate these updates to all other nodes. Thus, the time required for the state replication, named as system response time, depends on the delays between the leader and all other nodes. After multiple node failures and leadership transitions, each node can be leader with a probability that affects the expected response time. The leadership probabilities, in turn, are affected by the random intervals that nodes are waiting, after detecting a leader failure and before competing for the successive leadership. The Raft designers suggest the ranges of these intervals to be equal for all nodes. However, this may result in increased expected response time. In this paper, mathematical models are presented for estimating the ranges resulting in the desired leadership probabilities. The presented theoretical results are also confirmed by testbed experimentation with an open-source and widely used Raft implementation.

【Keywords】Voting; Time factors; Leadership; Delays; Heart beat; Protocols; Open source software; Raft; distributed-system; clustering; testbed-experimentation

【发表时间】2022 JUN

【收录时间】2022-06-22

【文献类型】实证性文章

【主题类别】

区块链技术-核心技术-共识机制