The goal of this release preview is to publish the pieces of spring-data-cassandra as they become available so that user's of the module can start to familiarize themselves with the components, and ultimately to provide the development team feedback. We hope this iterative approach produces the most usable and developer friendly spring-data-cassandra repository.

What's included (Q1 - 2014)

There are two modules included in the spring-data-cassandra repository: spring-cassandra and spring-data-cassandra.

Module `spring-cassandra`

This is the low-level core template framework, like the ones you are used to using on all your Spring projects. Our CqlTemplate provides everything you need for working with Cassandra using Spring's familiar template pattern.

This includes persistence exception translation, Spring JavaConfig and XML configuration support. Define your Spring beans to setup your Cassandra Cluster object, then create your Session and you are ready to interact with Cassandra using the CqlTemplate.

The module also offers table operation builders for CREATE TABLE, ALTER TABLE, and DROP TABLE operations, as well as XML namespace support for automatic keyspace creations and optional drops.

Module `spring-data-cassandra`

The spring-data-cassandra module depends on the spring-cassandra module and adds the familiar Spring Data features like repositories and lightweight POJO persistence.

Note: The code in the spring-data-cassandra module is a work in progress and is not yet functional.

We are actively working on its completion, but wanted to make the lower level Cassandra template functionality available to the Spring and Cassandra communities.

Best practices

We have worked closely with the DataStax Driver Engineering team to ensure that our implementation around their native CQL Driver takes advantage of all that it has to offer. If you need access to more than one keyspace in your application, create more than one CqlTemplate (one per session, one session per keyspace), then use the appropriate template instance where needed.

Here are some considerations when designing your application for use with spring-cassandra.

When creating a template, wire in a single Session per keyspace. Remember, Session is threadsafe, so only use one session per keyspace!
Cassandra's Session object is thread-safe, so you only need one per application & keyspace.
Do not issue USE <keyspace> commands on your session; instead, configure the keyspace name you intend to use.
The DataStax Java Driver handles all failover and retry logic for you. Become familiar with the Driver Documentation, which will help you configure your Cluster.
If you are using a Cassandra Cluster spanning multiple data centers, please be insure to include hosts from all data centers in your contact points.

High Performance Ingestion

We have included a variety of overloaded ingest() methods in the template for high performance batch writes.

What's Next (early Q1 - 2014): Spring Data Cassandra

The next round of work to do is to complete module spring-data-cassandra, while taking feedback from the community's use of module spring-cassandra.

Cassandra Admin Template

This is another Spring template class to help you with all of your keyspace and table administration tasks.

Cassandra Template

This template extends CqlTemplate to provide even more interaction with Cassandra using annotated POJOs. The Spring Data Cassandra Repository implementation is a client of CassandraTemplate. This data template gives the developer the capability of working with annotated POJOs and the template pattern without the requirement of the Spring Data Repository interface.

Cassandra Repository

The implementation of the standard Spring Data Repository interface for Cassandra.

Official Reference Guide

Once we have all the inner workings of the Repository interface completed, we will publish a full Reference Guide on using all of the features in spring-data-cassandra.

Examples

JavaConfig

Here is a very basic example to get your project connected to Cassandra 1.2 running on your local machine.

@Configuration
public class TestConfig extends AbstractCassandraConfiguration {

	public static final String KEYSPACE = "test";

	@Override
	protected String getKeyspaceName() {
		return KEYSPACE;
	}

	@Bean
	public CqlOperations CqlTemplate() {
		return new CqlTemplate(session().getObject());
	}
}

XML Configuration

<cassandra-cluster />
<cassandra-session keyspace-name="test" />
<cassandra-template />

Using CqlTemplate

public class CqlOperationsTest {

	@Autowired
	private CqlOperations template;
	
	public Integer getCount() throws DataAccessException {
	
		String cql = "select count(*) from table_name where id='12345'";
		
		Integer count = template.queryForObject(cql, Integer.class);
		
		log.info("Row Count is -> " + count);
		
		return count;
	}
}

Current Status

This community-led Spring Data subproject is well underway.

A first milestone (M1) is expected sometime in early 1Q14 built on the following artifacts (or more recent versions thereof):

Spring Data Commons 1.7.x
Cassandra 1.2
Datastax Java Driver 1.x
JDK 1.6+

The GA release is expected as part of the as-yet unnamed fourth Spring Data Release Train "D", following Spring Data Release Train Codd.

Cassandra 2.x

We are anticipating support for Cassandra 2.x and Datastax Java Driver 2.x in a parallel branch after the 1.x-based support has been released.

Source Repository & Issue Tracking

Source for this module is hosted on GitHub in Spring Projects.
The Spring Data Cassandra JIRA can be found here.

Reporting Problems

If you encounter a problem using this module, please report the issue to us using JIRA. Please provide as much information as you can, including:

Cassandra version
Community or DataStax distribution of Cassandra
JDK Version
Output of show schema where applicable
Any stacktraces showing the location of the problem
Steps to reproduce
Any other relevant information that you would like to see if you were diagnosing the problem.

Please do not post anything to Jira or the mailing list on how to use Cassandra. That is beyond the scope of this module and there are a variety of resources available targeting that specific subject.

We recommend reading the following:

Contact

For more information, feel free to contact the individuals listed below:

David Webb: dwebb at prowaveconsulting dot com
Matthew Adams: matthew dot adams at scispike dot com

Also, developer discussions are being hosted via Google Groups at https://groups.google.com/forum/#!forum/spring-data-cassandra.

Contributing Individuals

David Webb
Matthew Adams
John McPeek

Sponsoring Companies

Spring Data Cassandra is being led and supported by the following companies and individuals:

Prowave Consulting - David Webb
SciSpike - Matthew Adams
VHA

The following companies and individuals are also generously providing support:

DataStax
Spring @ Pivotal

README.md

Spring Data Cassandra Project Info

Release Preview