cluster with cross data center and local

[Keith Wright]

Hi all,

   I have a cluster with 2 data centers with an RF 2 keyspace using network 
topology on 1.1.10.  I would like to configure it such that some of the data is 
not cross data center replicated but is replicated between the nodes of the 
local data center.  I assume my only options are to create another cluster or 
to create another keyspace using LocalStrategy strategy?  What's the difference 
between LocalStrategy and SimpleStrategy?

Thanks!