> I have 4 nodes, then I I create one keyspace (such as FOO) with replica > factor =1 and insert an data, why I can see the directory of > /var/lib/Cassandra/data/FOO in every nodes? As I know, I just have one replica
The schema (keyspaces and column families) are global across the cluster (anything else would not make a lot of sense I think). The replication factor determines the number of replicas of actual data, based on row key. Given replication factor one, the data should only show up on one node (assuming a single row), but all nodes will be aware of your keyspace/column family. -- / Peter Schuller
