



        
        
        My create KeySpace command looks like this:

        CREATE KEYSPACE sales
         WITH REPLICATION = {'class' : 'NetworkTopologyStrategy',
                             'DataCenterWest' : 2, 'DataCenterEast' : 1};
                             
                             
       Cassandra uses the AP out of the CAP theorem, this means I to the 
       Partition Tolorance I need more than 1 copy of the records
       
       so... Where do I put these copies?
       
       the Replicaiton Strategy is critical, 
       
       the Ring is a collection of Nodes, somewhere in the Data Centers
       
       so i need to match the Node location to the physical location
       
       that is the job of the Snitch.
       
       Concepts:
       
       a Node is a Java application running on a physical server
       
       this server is in a Rack of machines, the Data Center has a collection of Racks
       so I want to avoid a Single Point Of Failure, and NOT put all my Nodes
       on the same Rack or the same Data Center
       
       
       the Snitch (like the Gossiper) keep track of Topology
       
       My example (3 Node Cluster) use a Network aware Snitch
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       

        
