For the remainder of our discussion of consistency, let's assume we're using a replication factor of three. That means, regardless of the total number of nodes we have in our cluster, any given piece of data will live on three different nodes.
Let's say we update the alice row in the users table, changing her e-mail address using the ONE consistency level. This means that the write should be considered a success as soon as one copy of the data is written durably. When the request is completed, we know that alice's new e-mail address has definitely been written to one node, but we don't know whether the change has propagated to the other two replicas.
If, immediately after writing the alice row, we attempt to ...
