write availability

[Marcelo Valle (BLOOMBERG/ LONDON)]

If I have an application that writes to a HBase cluster, can I count that the 
cluster will always available to receive writes? 
I might not be able to read if a region server which handles a range of keys is 
down, but will I be able to keep writing to other nodes, so everything get in 
sync when the other nodes get up again? 
Or I might get no write availability for a while?