AWS DMS Replication Instance Region for Cross-Region Migration
A company wants to migrate data from an Amazon RDS for PostgreSQL DB instance in the eu-east-1 Region of an AWS account named Account_A. The company will migrate the data to an Amazon Redshift cluster in the eu-west-1 Region of an AWS account named Account_B. Which solution will give AWS Database Migration Service (AWS DMS) the ability to replicate data between two data stores?
Community Votes
84% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.
Community Insight
The core trap is assuming the replication instance must match the source region; however, for Amazon Redshift targets, the DMS instance must reside in the same region as the target cluster.
This question addresses the placement of an AWS DMS replication instance when migrating data between different AWS accounts and regions, specifically involving Amazon Redshift as the target.
Many learners incorrectly choose Option D or B, believing the replication instance should be colocated with the source database (RDS) to minimize latency or simplify networking, ignoring the specific Redshift constraint.
Community Discussion (8 comments)
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Expert Analysis
Why the Answer Is Correct
The correct answer is A because AWS Database Migration Service (DMS) has a specific architectural requirement for Amazon Redshift targets: the replication instance must be deployed in the same AWS Region as the Redshift cluster. In this scenario, the target is in eu-west-1, so the replication instance must also be in eu-west-1. While it is common practice to place the DMS instance in the same region as the source for performance reasons with other databases (like RDS), Redshift requires co-location for VPC peering and endpoint configuration constraints.Why the Other Options Are Wrong
Option B places the instance in eu-east-1 (source region), which violates the Redshift co-location rule. Option C suggests a new account, which adds unnecessary complexity without solving the regional constraint. Option D is incorrect for the same reason as B; placing the instance in Account_A's source region prevents proper connectivity to the Redshift cluster in eu-west-1 under standard DMS configurations for Redshift.Community Comment Notes
Community comments heavily support Option A, citing official AWS documentation that states the replication instance must be in the same region as the Redshift target. Comments from users like 'andrologin' and 'lool' explicitly reference the prerequisite documentation. One user, 'samadal', incorrectly argued for Option D based on a general cross-region migration rule, but failed to account for the specific Redshift exception, leading to confusion among some voters.Official Reference
Exam Strategy
Always check if the target database type imposes specific regional constraints on the DMS replication instance. For Redshift, the rule is strict: same region as the target. For most other sources/targets, the instance can be anywhere with network access, but colocation with the source is often preferred for performance.
Frequently Asked Questions
Why can't DMS replicate from eu-east-1 to eu-west-1 directly?
DMS instances are regional resources. For Redshift, the instance MUST be in the same region as the target cluster due to VPC and endpoint constraints.
Is the DMS instance always in the source region?
No. While often placed near the source for performance, it must be in the same region as the target if the target is Amazon Redshift.
Related Analysis
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