1. Pre-Migration Backup & Snapshot
* Take full database backups before migration.
* Use incremental backups for large data sets.
* Capture database snapshots (for cloud databases like AWS RDS, Azure SQL).
2. Define Rollback Triggers
* Identify failure conditions that require rollback:
- Data corruption (integrity checks fail).
- Application errors (new system fails to process data).
- Performance issues (query execution time increases).
- Missing or incomplete records.
3. Choose the Right Rollback Method
A. Full Rollback (Complete Reversion) :
* Best for: Major failures or data corruption.
* How it works: Restore entire database from backup.
* Tools: AWS Backup, Oracle RMAN, SQL Server Backup.
B. Partial Rollback (Selective Reversion) :
* Best for: Minor failures (only some tables or records are affected).
* How it works: Restore only affected tables or partitions.
* Tools: Transaction logs, point-in-time recovery (PITR).
C. Hybrid Rollback (Incremental Correction)
* Best for: Continuous migration where only recent changes need to be reversed.
* How it works: Use Change Data Capture (CDC) to undo specific transactions.
* Tools: AWS DMS, Debezium, Apache Kafka.
4. Testing & Validation :
* Simulate rollback in a staging environment before migration.
* Use checksums & row counts to verify data consistency post-rollback.
* Automate rollback testing using scripts or CI/CD pipelines.
5. Monitoring & Logging :
* Enable real-time monitoring to detect migration issues early.
* Maintain detailed logs for audit trails.
* Set up alerts for migration failures.
