A quick question on cluster topology and partitions?

[John Wilson]

Hi,


   1. What exactly is a cluster topology? What makes a cluster topology
   invalid for further cache operations?
   2.  Why do we have the concept of partitions in Ignite? Why don't we
   have a key-to-node mapping rather than a key-to-partition and a
   partition-to-node mapping?

Thanks,
John