While reading the Quorum section, I wondered that are writes propagated to other nodes? I mean, as I can see, Quorum approach actually solves this issue (low availability of writes in a synchronous system), by making sure reads fall on at least one of the concurrently write-ordered node, but I just wanted to make sure, I am getting it right. If there is no propagation, so basically a node individually can hold a stale data, but it is not a problem due to the relationship between Vw and Vr features of quorum, am I right?
While following Quorum approach we make sure that every read operation should obtain a read quorum of replicas. Meanwhile, a write operation should obtain a write quorum and we ensure that a data item is not read and written by two operations concurrently. Also, at least one node receives both of the two write operations and imposes an order on them. This means that two write operations from two different operations cannot occur concurrently on the same data item.