Moving from RDBMS to NoSQL: Migration Best Practices for Apache Cassandra®

Migrating an application designed for a relational database to Apache Cassandra involves several steps and considerations. Firstly, assess if it's time for a change by identifying performance and scalability challenges in your current relational database. Prioritize use cases for migration and aim for incremental rather than big-bang migrations. Cassandra data modeling differs from relational data modeling; denormalization is the norm in Cassandra, and tables are designed based on application workflows to contain all required information in a single query. Load testing can help determine optimal cluster size and configuration. Updating application code involves using DataStax Drivers available in popular languages to connect to DataStax Enterprise or Cassandra clusters. Developers should familiarize themselves with Cassandra's distributed nature, consistency levels, lightweight transactions, and batches. Planning the Cassandra cluster includes considering factors like node configuration, data center placement, replication strategy, and hardware requirements. Lastly, perform a one-time data migration using tools like DataStax Bulk Loader or use Apache Kafka for zero-downtime migration. Validate results using Apache Spark to compare records from the source system with those in your Cassandra cluster. Throughout this process, resources such as DataStax Academy courses and blogs can provide valuable guidance and support.