Raft election cycles

[krgn]

Description

In a local setup with 2 machines, the Raft sub-system often causes re-election election for no apparent reason. According to the logs, these are due to election timeouts occurring when a follower doesn't receive the empty AppendEntries requests in time. We found that there are unusually high deltas between the last 2 requests in the leaders log, which are not really easily explainable.