  Consensus is one of the key problems in blockchains. There are many articles
analyzing the performance of threat models for blockchains. But the network
stability seems lack of attention, which in fact affects the blockchain
performance. This paper studies the performance of a well adopted consensus
algorithm, Raft, in networks with non-negligible packet loss rate. In
particular, we propose a simple but accurate analytical model to analyze the
distributed network split probability. At a given time, we explicitly present
the network split probability as a function of the network size, the packet
loss rate, and the election timeout period. To validate our analysis, we
implement a Raft simulator and the simulation results coincide with the
analytical results. With the proposed model, one can predict the network split
time and probability in theory and optimize the parameters in Raft consensus
algorithm.
