The answer is to use AWS DMS with ongoing replication from the on-premises MySQL database, which enables a near-zero downtime cutover by continuously syncing changes while the source remains live. This works because AWS DMS captures ongoing changes from the MySQL binary logs (binlog) and applies them to the target Amazon RDS instance, allowing you to stop the source application only after the target is fully caught up. On the AWS Certified Database Specialty DBS-C01 exam, this scenario tests your understanding of the full migration lifecycle, specifically the need for a stable, low-latency network connection—such as AWS Direct Connect or a VPN—to maintain replication integrity and avoid data loss during the final cutover window. A common trap is assuming a one-time full load is sufficient, but the question explicitly demands minimal downtime and ongoing replication, which only CDC (Change Data Capture) via DMS provides. Memory tip: think “DMS + binlog + Direct Connect” as the three pillars of a zero-downtime MySQL migration.
DBS-C01 Deployment and Migration Practice Question
This DBS-C01 practice question tests your understanding of deployment and migration. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company is planning to migrate a 1 TB MySQL database from on-premises to Amazon RDS for MySQL. The migration must have minimal downtime and support ongoing replication. Which THREE steps should the company include in the migration plan? (Choose THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Set up an AWS Direct Connect or VPN connection between on-premises and AWS.
Option A is correct because a stable, low-latency network connection (Direct Connect or VPN) is essential for AWS DMS to perform ongoing replication with minimal downtime. Without this, the replication can be interrupted by network issues, causing data loss or extended cutover windows.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Set up an AWS Direct Connect or VPN connection between on-premises and AWS.
Why this is correct
Network connectivity is required for DMS to access the source.
Related concept
Read the scenario before looking for a memorised answer.
✗
Deploy an Amazon EC2 instance to act as a proxy for the DMS replication.
Why it's wrong here
DMS can connect directly to the source; a proxy is unnecessary.
✓
Create the target Amazon RDS for MySQL instance.
Why this is correct
The target database must be provisioned before migration.
Related concept
Read the scenario before looking for a memorised answer.
✓
Use AWS DMS with ongoing replication from the on-premises MySQL database.
Why this is correct
Ongoing replication minimizes downtime by capturing changes.
Related concept
Read the scenario before looking for a memorised answer.
✗
Install the AWS Schema Conversion Tool on the source server to convert the schema.
Why it's wrong here
Schema conversion is not needed since the target is also MySQL.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume an EC2 proxy is needed for DMS replication, but DMS replication instances handle connectivity directly, and the proxy is only used in specific scenarios like VPC peering across regions or complex network topologies.
Detailed technical explanation
How to think about this question
AWS DMS ongoing replication uses Change Data Capture (CDC) by reading the MySQL binary logs (binlog) in row-based format. The source database must have binlog retention enabled, and the DMS replication instance must have network connectivity to both the on-premises source and the RDS target, which is why a Direct Connect or VPN is critical for consistent throughput and low latency.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Deployment and Migration — This question tests Deployment and Migration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Set up an AWS Direct Connect or VPN connection between on-premises and AWS. — Option A is correct because a stable, low-latency network connection (Direct Connect or VPN) is essential for AWS DMS to perform ongoing replication with minimal downtime. Without this, the replication can be interrupted by network issues, causing data loss or extended cutover windows.
What should I do if I get this DBS-C01 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company is migrating a 500 GB MySQL database from on-premises to Amazon RDS for MySQL. The migration must have minimal downtime and support ongoing replication. Which AWS service should be used?
medium
A.Use mysqldump to export the database and import to RDS during a maintenance window.
B.Use AWS Schema Conversion Tool (SCT) to convert the schema and migrate data.
C.Take a physical backup, copy it to Amazon S3, and restore to RDS.
✓ D.Use AWS Database Migration Service (DMS) with a full load and ongoing replication from a change data capture source.
Why D: AWS DMS is the correct choice because it supports both a full load of the 500 GB database and ongoing replication using change data capture (CDC) from the on-premises MySQL source. This enables minimal downtime by keeping the target RDS instance synchronized during the migration window, and it handles schema conversion automatically for MySQL-to-MySQL migrations without needing a separate tool.
Variation 2. A company is migrating a 2 TB MySQL database from on-premises to Amazon RDS for MySQL. They need to minimize downtime and ensure data consistency. They plan to use AWS DMS. What is the first step they should take before starting the migration task?
easy
A.Create a read replica of the source database to reduce load.
✓ B.Enable binary logging (binlog) on the source MySQL database.
C.Disable foreign key checks on the source database to speed up the load.
D.Enable binary logging on the target RDS for MySQL instance.
Why B: AWS DMS requires binary logging (binlog) to be enabled on the source MySQL database to capture ongoing changes during the full-load and change data capture (CDC) phase. This ensures data consistency and minimizes downtime by allowing DMS to replicate incremental changes after the initial load. Without binlog, DMS cannot perform CDC, and the migration would be limited to a one-time snapshot, risking data loss or extended downtime.
Variation 3. A company is migrating a 500 GB MySQL database from on-premises to Amazon RDS for MySQL. The database is critical and must have minimal downtime. Which approach should be used to migrate the database with the least downtime?
medium
✓ A.Use AWS Database Migration Service (DMS) with a replication instance to perform a full load and then ongoing replication until cutover.
B.Modify the on-premises database to use a new master user and then use the AWS Schema Conversion Tool to migrate.
C.Create a read replica of the on-premises database and promote it to a standalone RDS instance.
D.Export the database using mysqldump and import into RDS using mysql command-line tool. Schedule a maintenance window for cutover.
Why A: Option C is correct because AWS Database Migration Service (DMS) with ongoing replication allows migration with minimal downtime by continuously replicating changes from the source to the target until cutover. Option A is wrong because creating a read replica is not possible from on-premises. Option B is wrong because exporting and importing will cause significant downtime. Option D is wrong because changing the master user is unrelated to migration.
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Question Discussion
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