Formal Specification and Model Checking of Raft Leader Election in Maude*

Abstract

Raft is widely known as one of the distributed consensus protocols and is used to build highly available and strongly consistent services. Using Maude, we formally specify the leader election in Raft and conduct model checking to check whether the protocol enjoys the Election Safety Property that at most one leader can be elected in each logical time, which is one of the properties that Raft is expected to guarantee. Our model checking experiments show that the protocol enjoys the property under the condition that we limit the logical time and the number of servers. We also aim to promote understanding of the leader election in Raft.