Cassandra lose datas

[ilhami Kalkan]

Hi all,
I'm new to Gora. I want to insert datas to cassandra with gora. I have 
successfully saved datas to db but about 1 minute they are removed from 
db. Do you know why? I add my source codes below

public class CassandraTest {

    public static void main(String[] args) {

        DataStore<String, users> datastore = null;

        try {
            datastore = DataStoreFactory.createDataStore(
                    (Class<? extends DataStore<String, users>>) Class
.forName("org.apache.gora.cassandra.store.CassandraStore"),
                    String.class, users.class, new Configuration());
        } catch (GoraException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


        users user = users.newBuilder().build();
        user.setAge(1);
        user.setName(new Utf8("foo1"));
        user.setSurname(new Utf8("example"));

        datastore.put(user.getName().toString(), user);
        datastore.flush();

        datastore.close();
    }