DBS-C01 Deployment and Migration Practice Question
A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server. They use AWS DMS with full load and ongoing replication. After the full load completes, they observe that the ongoing replication is falling behind and the target database is not consistent. The source database has high transaction volume. What is the most effective way to improve replication performance?
⚠ Common exam trap
Many exam-takers confuse full-load parallelism (multiple tasks) with CDC performance, or assume that disabling logging or toggling batch apply will fix lag, when the root cause is insufficient instance compute capacity for high-volume transactional workloads.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increase the size of the DMS replication instance (e.g., from dms.c5.xlarge to dms.c5.2xlarge).
Increasing the DMS replication instance size (Option D) provides more CPU and memory resources, which directly addresses the bottleneck caused by high transaction volume on the source. A larger instance can process and apply changes faster, reducing the replication lag and improving consistency. This is the most effective single action because it scales the entire replication pipeline without altering the task configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Disable CloudWatch logging for the DMS replication instance.
Why it's wrong here
Disabling logging has minimal impact on replication performance.
- ✗
Configure multiple parallel load tasks for ongoing replication.
Why it's wrong here
Parallel load is for full load; ongoing replication uses a single task.
- ✗
Enable batch apply mode in the DMS task.
Why it's wrong here
Batch apply can improve apply speed but may not address capture performance.
- ✓
Increase the size of the DMS replication instance (e.g., from dms.c5.xlarge to dms.c5.2xlarge).
Why this is correct
A larger instance provides more resources to process transactions faster.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DBS-C01 exam.