Knowledge and Common Knowledge in a Distributed Environment, Part 1

Saraswati, goddess of knowledge We usually reason about distributed systems by asking, what can one process know about the state of the system? E.g., if a majority of Raft nodes tell the leader that they have replicated a log entry, the leader knows the entry is durable. Therefore the leader can take various actions, like replying to the user who submitted the log entry. On the other hand, if a…