State machines
These compact machines show durable lifecycle boundaries. Workflow status does not automatically change protocol visibility; the authority column remains decisive.
Stream
ACTIVE permits append/read, SEALED permits historical read but blocks new append, DELETING
blocks new ordinary operations, and DELETED is the logical terminal state while physical GC may
continue.
Higher generation
Only COMMITTED index publication makes a generation a reader candidate.
Physical Object root
Object LIST discovers possible orphans but cannot authorize a transition. A deletion journal makes
DELETING restartable after process or response failure.
Append outcome
KNOWN_NOT_COMMITTED -> safe to start a new attempt
MAY_HAVE_COMMITTED -> recover the original attempt and suspend the stream lane
KNOWN_COMMITTED -> do not append again; finish index/Object completion or return the result
The outcome describes commit certainty and is orthogonal to timeout, fencing, and metadata-unavailable error codes.