ldlework: well, currently there's minimum and maximum replication. You can set both to -1 for "everywhere". If you set minimum and maximum it means that maximum replication is the replication where it starts with, while minimum is the replication where it will start to create another copy (wenn it drops below).

So if you use 10 as maximum and 4 as minimum, the cluster will hold 10 copies for everything.

If one node goes offline, the cluster will hold 9 copies.

If 7 nodes goes offline, the replication will drop below 4 and another copy will be made :)

( A simplified example )