I don't understand about how Hbase works but I will try to answer based on
your abstraction here.
As other people already said, if you want to use ZK's notification (watch)
of a single znode as mechanism to drive a state transition of another peer
then it is not going to work.
If want you really need is a reliable notification, ZK doesn't not provide
this mechanism directly. However, you might be able to implement it on top
of ZK by storing each state transition as an individual znode, then it
might be possible to have a peer subscribe to all the state transition.
"Suitable" is a tricky word. You might be able to find other systems which
provide the exact mechanism that you want but then you have to evaluate if
it fit your reliability, throughput or other requirements or not.