[sewen]

There is nothing to coordinate for the application, because, yes, the log coordinates everything. But not globally, on the level of a single event handler execution, or a single key.

That has been proven to scale well - the way we implement that in Restate is classical shared nothing physical partitioning, with indexing on a key granularity.

So nothing like a shared mutex unless you want to access the same key, which otherwise your database synchronizes, if you want any reasonable level of consistency.