title: How to do data migration of Cassandra from one keyspace to another keyspace?
body: <p>I created an old keyspace in Cassandra cluster but found the definition of its "comparator" is wrong, so I have to recreate a new keyspace and do data migration. Is there any tool to do data migration? or I have to program with Thrift client read all data from old keyspace and write them to new keyspace? Any suggestions or code snippets is welcome!</p>