Phase 2: Migrate and validate data
In Phase 2 of data migration, you migrate data from the origin to the target, and then validate the migrated data.
This topic introduces data migration tools that you can use during Phase 2 of your migration project:
- Cassandra Data Migrator (CDM)
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Best for migrating large amounts of data and for migrations that need support for detailed logging, data verification, table column renaming, and reconciliation.
- DSBulk Migrator
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Extends DSBulk Loader with migration-specific commands. Best for simple migration of smaller amounts of data quantities, and migrations that don’t require support for data validation during the migration.
- Astra DB Sideloader
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Exclusively for migrations from a Apache Cassandra®, DataStax Enterprise (DSE), or Hyper-Converged Database (HCD) cluster to an Astra DB database. You can use CDM to validate data after the migration.
Cassandra Data Migrator
CDM offers extensive functionality and configuration options to support large and complex migrations as well as post-migration data validation.
For more information, see Cassandra Data Migrator and the Cassandra Data Migrator repository.
DSBulk Migrator
DSBulk Migrator, which is based on DSBulk Loader, is best for migrating smaller amounts of data or when you can shard data from table rows into more manageable quantities.
DSBulk Migrator provides the following commands:
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migrate-live: Start a live data migration using the embedded version of DSBulk Loader or your own DSBulk Loader installation. A live migration means that the data migration starts immediately and is performed by this migrator tool through the specified DSBulk Loader installation. -
generate-script: Generate a migration script that you can execute to perform a data migration with a your own DSBulk Loader installation. This command doesn’t trigger the migration; it only generates the migration script that you must then execute. -
generate-ddl: Read the schema from origin, and then generate CQL files to recreate it in your target Astra DB database.
For more information, see DSBulk Migrator and the DSBulk Migrator repository.
Astra DB Sideloader
Astra DB Sideloader is a service running in Astra DB that directly imports data from snapshot backups that you’ve uploaded to Astra DB from an existing Cassandra, DSE, or HCD cluster.
Because it imports data directly, Astra DB Sideloader can offer several advantages over CQL-based tools like DSBulk Migrator and Cassandra Data Migrator, including faster, more cost-effective data loading, and minimal performance impacts on your origin cluster and target database.
Astra DB Sideloader uses the Astra DevOps API, your cloud provider’s CLI, and nodetool.
For more information, see About Astra DB Sideloader.
