DOP-C02 Resilient Cloud Solutions Practice Question
A company is designing a multi-region active-active architecture for a stateless web application. The application uses a DynamoDB table as its data store. The company wants to minimize write latency and ensure that writes are accepted in any region with eventual consistency. Which DynamoDB feature should they use?
⚠ Common exam trap
Many candidates confuse DynamoDB Accelerator (DAX) as a solution for multi-region writes, but DAX only caches reads in a single region and does not replicate writes across regions.
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
✓
DynamoDB global tables.
DynamoDB global tables provide a fully managed, multi-region, multi-active solution that automatically replicates data across AWS Regions. This enables low-latency writes in any region with eventual consistency, meeting the requirement for an active-active architecture without custom code or additional infrastructure.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
DynamoDB read replicas in each region.
Why it's wrong here
Read replicas are a database feature used to offload read traffic, typically found in relational databases like Amazon Aurora. Unlike Aurora, DynamoDB does not have a separate read-replica construct; even if you placed read replicas in each region, they would be read-only and unable to accept writes. An active-active architecture requires every region to accept both reads and writes, so read replicas alone cannot satisfy the write requirements. DynamoDB's native multi-master replication, via global tables, is the appropriate mechanism instead.
- ✗
Cross-region replication using AWS Lambda function.
Why it's wrong here
Replicating data across regions with Lambda involves subscribing to a DynamoDB Stream and building custom code to apply incoming writes to a table in another region. This approach introduces significant operational complexity from managing source/destination mappings, retries, and idempotency to prevent duplicate or out-of-order writes. It also adds latency because every write must traverse an asynchronous pipeline, and without native conflict resolution logic you must handle divergent updates manually. Lambda-based replication is a brittle, partial solution compared to DynamoDB global tables, which perform managed replication with automatic conflict resolution.
- ✓
DynamoDB global tables.
Why this is correct
Amazon DynamoDB global tables provide a fully managed multi-Region, multi-master replication solution that maintains two or more identical tables across AWS Regions. When a write is issued to any replica, DynamoDB automatically propagates that write to every other region using DynamoDB Streams, with last-writer-wins conflict resolution to reconcile concurrent updates. This makes global tables the appropriate choice for an active-active architecture because each region can accept both reads and writes while providing low-latency access for geographically distributed users. The service handles the replication plumbing, versioning, and conflict resolution internally, eliminating the need for custom code.
- ✗
DynamoDB Accelerator (DAX) with multi-region endpoints.
Why it's wrong here
DynamoDB Accelerator (DAX) is a fully managed in-memory cache that sits in front of DynamoDB to accelerate reads, and it operates entirely within a single region. While you could deploy DAX clusters with endpoints in multiple regions, each cluster only caches data served from its local DynamoDB table; it does not replicate data between regions nor does it accept or propagate writes. The cache is not a source of truth and can serve stale data, making it unsuitable for active-active replication of authoritative state. At best, DAX would sit alongside global tables to improve read performance, not replace the underlying replication layer.
Go deeper
Related to this question
About these practice questions
This DOP-C02 question is part of Courseiva's 1,298-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DOP-C02 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 DOP-C02 exam.