A brief overview of some of the features of Spring Data Cassandra. Loosely based on material from .... http://www.infoq.com/presentations/spring-data-cassandra-couchbase Find an example project referenced in the slides here. https://github.com/digbigdata/sdcassandra/ And more information about us on digbigdata.com

1. CASSANDRA
INTEGRATION
Spring Data

2. CASSANDRA INTRO

3. SPRING DATA
CASSANDRA

4. Rationale
• Reduces ramp up time and code required to work with
Cassandra
• Clear, annotation based mappings for java objects to
Cassandra tables
• Good fit if already using spring data / spring boot
• Minimal property based configuration

5. Features
• Uses common spring data repository pattern
• Synchronous and Asynchronous requests via the
DataStax Java Driver
• XML based CQL schema creation
• JavaConfig / XML support via properties
• QueryBuilder interface for complex query creation.

6. Annotated POJOs
• Allows easy mapping of annotated POJOs to Cassandra
tables.
@Table("users")
public class User {
@PrimaryKey("user_id")
private String userId;
@Column("first_name")
private String firstName;
@Column("last_name")
private String lastName;
private String password;

7. Spring Repository Support
• Basic Support of Spring Data Repository pattern.
• Provides CRUD operations without code, findOne, findAll,
save (upsert), delete.
• Easily extensible with custom queries.
public interface UserRepository extends CassandraRepository<User> {
@Query("select * from users where user_id = ?0")
User findByUserId(String userId);
}

8. Primary Keys
• Easily define simple, compound or composite primary
keys. Allows for narrow or wide rows.
• Simple Key example:
@PrimaryKey("user_id")
private String userId;
• Compound Key with Cluster Column Example:
@PrimaryKeyColumn(name = "eid", ordinal = 0, type = PrimaryKeyType.PARTITIONED)
private Integer eid;
@PrimaryKeyColumn(name = "day", ordinal = 1, type = PrimaryKeyType.PARTITIONED)
private Integer day;
@PrimaryKeyColumn(name = "event_id", ordinal = 2, type = PrimaryKeyType.CLUSTERED)
private UUID eventId;

9. Query Support
• No support for spring data “findBy” style queries at
present, e.g. findByNameLikeOrderBy
• Use @Query annotation for custom queries
@Query("select * from events_by_tag where eid = ?0 and tag = ?1")
List<Event> findByEidAndTag(Integer eid, String tag);

10. Query Support
• Use static BasicMapId.id() to construct primary key based
queries.
MapId id = id()
.with("eid", 1)
.with("day", 12345)
.with("eventId”, “XXXX-XXXX-XXXX”);
return eventsByDayRepository.findOne(id);

11. Or use Java Driver QueryBuilder
• Use QueryBuilder to create queries including batch and
transaction based queries.
Select select = QueryBuilder
.select()
.all()
.from(“events_by_day”)
.where(eq("eid", 1))
.and(eq("day", 12345))
.and(eq("eventId", “XXXX-XXXX-XXXX”));
return cassandraOperations
.select (select, Event.class);

12. DEMO