I may have misunderstood, but I think they're using the log as a write ahead log, which is a similar, but subtly different idea to event logging. A Write Ahead

I may have misunderstood, but I think they're using the log as a write ahead log, which is a similar, but subtly different idea to event logging. A Write Ahead Log is an implementation detail of a distributed system, whereby the system has a log of actions it applies against a state machine. Protocols, such as Raft, exist to keep the log in sync, and the state machine is kept in sync as a consequence. The log entries would be quite abstract and low-level, like "tuple inserted". An Event Log, on the other hand, is an application level architecture technique. The log entries would be application-specific actions, like "user logged in".