To manage our database migrations for Cassandra, we've taken to creating scripts that create/modify the schema and populate configuration data. In my previous post, I showed how to dump and load the schema (keyspaces and column families).

Here is a code snippet that lets you dump the data into set statements that you can then load via the CLI.

 public void dumpColumnFamily() { 
 String columnFamily = "YOUR_COLUMN_FAMILY"; 
 Cluster cluster = HFactory.getOrCreateCluster("dev", "localhost:9160"); 
 Keyspace keyspace = HFactory.createKeyspace("YOUR_KEYSPACE", cluster); 
 RangeSlicesQuery<String, String, String> rangeSlicesQuery = HFactory 
 .createRangeSlicesQuery(keyspace, StringSerializer.get(), 
 StringSerializer.get(), StringSerializer.get()); 
 rangeSlicesQuery.setColumnFamily(columnFamily); 
 rangeSlicesQuery.setKeys("", ""); 
 rangeSlicesQuery.setRange("", "", false, 2000); // MAX_COLUMNS 
 rangeSlicesQuery.setRowCount(2000); // MAX_ROWS 
 QueryResult<OrderedRows<String, String, String>> result = rangeSlicesQuery .execute(); 
 OrderedRows<String, String, String> orderedRows = result.get(); 
 for (Row<String, String, String> r : orderedRows) { 
 ColumnSlice<String, String> slice = r.getColumnSlice(); 
 for (HColumn<String, String> column : slice.getColumns()) { 
 System.out.println("set " + columnFamily + "['" + r.getKey() 
 + "']" + "['" + column.getName() + "'] = '" 
 + column.getValue() + "';"); 
 } 
 } 
 }