Top 10 AWS Database Migration Service (DMS) Interview Questions and Answers

I have compiled a list of top 10 AWS Database Migration Service (DMS) interview questions and answers. These questions should help you prepare for interviews related to AWS DMS.

1. What is AWS Database Migration Service (DMS)?

AWS DMS is a managed service that enables migration of data between different types of databases, as well as migration from on-premises databases to AWS and vice versa, with minimal downtime. DMS supports both homogeneous (same database engine) and heterogeneous (different database engines) migrations.

2. What are the key components of AWS DMS?

The key components of AWS DMS are:

• Replication instance: A managed EC2 instance responsible for processing the migration tasks.
• Source and target endpoints: Database connections to source and target databases.
• Replication tasks: Jobs that define the migration process, including source, target, and migration type.

3. What are the supported source and target database engines in AWS DMS?

AWS DMS supports a wide range of database engines, including:

• Oracle, Microsoft SQL Server, MySQL, PostgreSQL, and MariaDB as both source and target.
• Amazon RDS, Amazon Aurora, Amazon Redshift, and Amazon DynamoDB as target only.
• SAP ASE, MongoDB, and IBM Db2 as source only.

4. Can you perform a schema conversion using AWS DMS?

No, AWS DMS does not perform schema conversions. For this purpose, you can use AWS Schema Conversion Tool (SCT), which helps convert the source database schema to a compatible schema for the target database.

5. What are the different types of migration supported by AWS DMS?

AWS DMS supports three types of migration:

• Full load: Migrates the entire dataset from the source to the target database.
• Change data capture (CDC): Captures and migrates incremental changes from the source to the target database.
• Full load plus CDC: Combines both methods, migrating the entire dataset initially and then applying incremental changes.

6. How does AWS DMS handle primary key and foreign key constraints?

AWS DMS does not enforce primary key and foreign key constraints during migration. However, it does maintain the order of the transactions and preserves data integrity.

7. Can you migrate data from multiple source databases to a single target database using AWS DMS?

Yes, you can use AWS DMS to migrate data from multiple source databases to a single target database by creating separate tasks for each source-target pair.

8. Is AWS DMS suitable for migrating large databases?

Yes, AWS DMS is designed to handle large-scale migrations. However, it is essential to size the replication instance appropriately based on the amount of data to be migrated, and it may also be necessary to increase the allocated storage.

9. How do you monitor the progress of an AWS DMS migration?

You can monitor the progress of an AWS DMS migration using CloudWatch metrics, which provide information on the status, latency, and throughput of the migration. You can also review the DMS task logs and history.

10. How do you ensure the security of data during migration with AWS DMS?

AWS DMS ensures the security of data during migration by encrypting the data at rest (using AWS KMS) and in transit (using SSL/TLS). Additionally, you can configure VPC and security groups to restrict access to the replication instance and databases.