Hello Everyone,

Is there a practical formula for determining Cassandra system requirements using OrderPreservingPartitioner ?

We have hundreds of millions of rows in a single column family with a potential target of maybe a billion rows.

How can we estimate the Cassandra system requirements given factors such as:
 
N=number of nodes
M=memory allocated for Cassandra
R=replication factor
K=key size
D=individual column data size
CR=columns/row
NR=number of rows (keys) in column family

It seems like the compaction process gets more stressed as we add more data, but I have no idea how close we are
to a breaking point.

Thanks,
Jon