Apache Cassandra is a highly scalable and distributed NoSQL database management system designed to handle large amounts of data across many commodity servers. It was developed at Facebook and later became an Apache Software Foundation project.

In the previous post we discussed how Cassandra can help in application scaling using a gossip protocol, Please follow the link to find out more Link:

Why is Apache Cassandra well-suited for use with Spring Boot?

Apache Cassandra is a popular NoSQL database that is well-suited for use with Spring Boot due to several key reasons. Here's why:

Firstly, Apache Cassandra's flexible data model makes it easy to store and query complex data structures, such as JSON, without the need for complex data transformations. This means that developers can use Spring Boot to build applications that can easily read and write data to and from Cassandra without worrying about data normalization or schema management.

Secondly, Apache Cassandra's high scalability and fault-tolerance make it ideal for building distributed systems that can handle large volumes of data and traffic. When used with Spring Boot, developers can take advantage of Cassandra's built-in replication and sharding capabilities to ensure that their applications are highly available and can withstand hardware failures.

Thirdly, Spring Boot's support for reactive programming makes it easy to build scalable and responsive applications that can handle concurrent requests and streams of data. When combined with Cassandra's support for asynchronous I/O and non-blocking APIs, developers can build high-performance, reactive applications that can handle a large number of concurrent users and requests.

Finally, both Apache Cassandra and Spring Boot are open-source and have large and active communities. This means that developers can easily find support, documentation, and resources for building and deploying applications that use these technologies.

How to configure Apache Cassandra on Spring Boot?

To connect a Spring Boot application to multiple Apache Cassandra clusters, you can follow these steps:

1. Add the Cassandra driver to your application’s classpath. You can do this by adding the following dependency to your pom.xml file (for Maven projects) or by adding the Cassandra driver jar file to your project’s classpath:

<dependency>
<groupId>com.datastax.oss</groupId>
<artifactId>java-driver-core</artifactId>
<version>4.9.0</version>
</dependency>

2. Configure the Cassandra connection details for each cluster in your Spring Boot application.properties or application.yml file:

spring.data.cassandra.cluster1.keyspace-name=<your_keyspace_name>
spring.data.cassandra.cluster1.contact-points=
spring.data.cassandra.cluster1.port=9042

spring.data.cassandra.cluster2.keyspace-name=<your_keyspace_name>
spring.data.cassandra.cluster2.contact-points=
spring.data.cassandra.cluster2.port=9042

3. Create a Cassandra configuration class for each cluster by extending AbstractCassandraConfiguration and providing the Cassandra entity classes and keyspace name.

@Configuration
@EnableCassandraRepositories(basePackages = "com.example.repository.cluster1",
cassandraTemplateRef = "cassandraTemplateCluster1")
public class CassandraConfigCluster1 extends AbstractCassandraConfiguration {

@Override
protected String getKeyspaceName() {
return "<your_keyspace_name>";
}

@Override
public SchemaAction getSchemaAction() {
return SchemaAction.CREATE_IF_NOT_EXISTS;
}

@Override
public String[] getEntityBasePackages() {
return new String[]{"<your_package>.model.cluster1"};
}
}

@Configuration
@EnableCassandraRepositories(basePackages = "com.example.repository.cluster2",
cassandraTemplateRef = "cassandraTemplateCluster2")
public class CassandraConfigCluster2 extends AbstractCassandraConfiguration {

@Override
protected String getKeyspaceName() {
return "<your_keyspace_name>";
}

@Override
public SchemaAction getSchemaAction() {
return SchemaAction.CREATE_IF_NOT_EXISTS;
}

@Override
public String[] getEntityBasePackages() {
return new String[]{"<your_package>.model.cluster2"};
}
}

4. Create a CassandraTemplate bean for each cluster

@Bean
@Primary
public CassandraTemplate cassandraTemplateCluster1(Session sessionCluster1) {
return new CassandraTemplate(sessionCluster1);
}

@Bean
public CassandraTemplate cassandraTemplateCluster2(Session sessionCluster2) {
return new CassandraTemplate(session

5. Create Cassandra entities that represent your data model. For example:

@Table("employee")
public class Employee {

@PrimaryKey
private int id;

private String name;
private int age;

// getters and setters ...
}

6. Inject the repository into your Spring Boot service and use it to perform CRUD operations on Cassandra. For example:

@Service
public class EmployeeService {

@Autowired
private EmployeeRepository employeeRepository;

public Employee save(Employee employee) {
return employeeRepository.save(employee);
}

public List findAll() {
return employeeRepository.findAll();
}

// ...
}

Summary

Apache Cassandra is a highly scalable NoSQL database, and Spring Boot is a popular Java framework for building microservices and web applications. The combination of Cassandra and Spring Boot provides several advantages for developers, including simplified configuration, improved developer productivity, easy data access, improved scalability, integration with other Spring projects, and easy testing. To use Cassandra with Spring Boot, developers need to add Cassandra dependencies to their project and configure a Cassandra connection in the Spring Boot application.