> that desired shouldn't be a separately stored thing, and only serves to confuse us whenever storing things in Cassandra goes horribly wrong

@lvh My worry is primarily due to launch/delete server failures causing deviation between desired and real instead of cassandra failure. We can avoid CASS failures by storing desired as set of immutable changes.  Nova failures was (I think) the primary reason why we thought of having desired and always converging to that (if it fails once, it tries some other time and gets fixed).