Database replication for migration is a crucial cloud concept that enables organizations to move their data from on-premises environments or other cloud platforms to AWS with minimal downtime and data loss. This process involves creating and maintaining synchronized copies of databases across diffe…Database replication for migration is a crucial cloud concept that enables organizations to move their data from on-premises environments or other cloud platforms to AWS with minimal downtime and data loss. This process involves creating and maintaining synchronized copies of databases across different locations or systems during the migration journey.
In AWS, database replication for migration typically leverages services like AWS Database Migration Service (DMS), which facilitates continuous data replication between source and target databases. This approach allows businesses to keep their source database fully operational while data is being transferred to the destination, ensuring business continuity throughout the migration process.
The replication process works by capturing changes made to the source database in real-time and applying them to the target database. This is often referred to as Change Data Capture (CDC). As transactions occur on the source system, they are logged and transmitted to the target, keeping both databases synchronized until the final cutover.
Key benefits of database replication for migration include reduced downtime since applications can continue running during the transfer, data integrity validation between source and target systems, and the ability to perform testing on the replicated data before completing the migration. Organizations can also use this approach for heterogeneous migrations, moving data between different database engines such as Oracle to Amazon Aurora or SQL Server to Amazon RDS.
AWS supports both homogeneous migrations where source and target databases are the same type and heterogeneous migrations involving different database platforms. The Schema Conversion Tool works alongside DMS to transform database schemas when switching between different database engines.
Database replication ensures that mission-critical applications experience minimal disruption while transitioning to cloud infrastructure, making it an essential strategy for enterprises modernizing their data infrastructure on AWS.
Database Replication for Migration - AWS Cloud Practitioner Guide
What is Database Replication for Migration?
Database replication for migration is the process of copying and synchronizing data from a source database to a target database, typically when moving workloads to the cloud or between different database platforms. In AWS, this is primarily accomplished using AWS Database Migration Service (DMS).
Why is it Important?
• Minimal Downtime: Keeps source databases operational during migration • Data Consistency: Ensures all data is accurately transferred to the target • Risk Reduction: Allows testing before final cutover • Cost Efficiency: Reduces the complexity and resources needed for migrations • Flexibility: Supports homogeneous (same engine) and heterogeneous (different engines) migrations
How Does it Work?
1. Continuous Data Replication: AWS DMS creates a replication instance that connects to your source database, reads the data, and writes it to the target database.
2. Change Data Capture (CDC): After the initial full load, DMS captures ongoing changes from the source and applies them to the target, keeping both synchronized.
3. Schema Conversion: For heterogeneous migrations, the AWS Schema Conversion Tool (SCT) converts database schemas and code to match the target platform.
Key AWS Services: • AWS DMS - Handles the actual data migration and replication • AWS SCT - Converts schemas for different database engines
Supported Migration Types: • On-premises to AWS • AWS to AWS • Other cloud providers to AWS
Exam Tips: Answering Questions on Database Replication for Migration
• When a question mentions migrating databases with minimal downtime, think AWS DMS • If the question involves moving from one database engine to another (e.g., Oracle to Aurora), remember you need both SCT and DMS • AWS DMS supports continuous replication, making it ideal for keeping source and target synchronized • Remember that the source database remains fully operational during migration • DMS is a managed service - AWS handles the infrastructure • For questions about migrating large databases or data warehouses, DMS is typically the answer • Know that DMS can replicate to Amazon RDS, Aurora, Redshift, S3, and DynamoDB • If a question asks about converting stored procedures or database code, the answer involves Schema Conversion Tool • DMS pricing is based on the replication instance and data transfer - understand this is pay-as-you-go