S3 Multi-Region Access Point and Replication Strategy
Short answer
CE Configure bidirectional replication among all three buckets and modify the application to use the S3 Multi-Region Access Point ARN for both streaming and uploads.
Question
Key Takeaways
It tests the distinction between unidirectional replication chains and bidirectional synchronization, as well as the specific capabilities of S3 Multi-Region Access Points (MRAP) for both reading and writing.
This question evaluates the optimal design for global content delivery using Amazon S3, specifically balancing low-latency uploads with efficient data replication across multiple regions.
Common mistake: Many candidates choose A and D, assuming that because the source is us-east-2, one-way replication is sufficient. This fails to account for the requirement to minimize latency for developers who might upload from other regions if they were present, or more critically, it misinterprets 'fewest changes' by ignoring that MRAP handles global routing natively while requiring application code changes for write consistency in a multi-writer scenario.
Expert Analysis
Why the Answer Is Correct
The correct combination is C and E. The question asks for the FEWEST changes to the application while meeting latency requirements for both streaming and uploading globally. Option C (Bidirectional replication) ensures that any video uploaded to ANY region is immediately available in all others, solving the latency problem for developers who might be near eu-west-2 or ap-southeast-1. If we only did one-way (A), a developer in EU would have to upload to US (high latency). Option E uses an S3 Multi-Region Access Point (MRAP). MRAP provides a single endpoint that routes requests to the nearest region. By modifying the app to use the MRAP ARN for BOTH streaming and uploads, we leverage AWS's global routing to direct uploads to the closest region (minimizing upload latency) and streams from the closest region (minimizing read latency). Bidirectional replication then keeps these regional copies in sync.
Why the Other Options Are Wrong
Option A suggests one-way replication from us-east-2. This assumes all uploads happen in us-east-2, which contradicts the goal of minimizing latency for global developers. If a developer in Europe uploads, they suffer high latency to us-east-2. Option B creates a chain (us->eu->ap), which adds complexity and potential sync delays, failing the 'fewest changes' and latency goals. Option D suggests using MRAP only for streaming but not uploads. This forces uploads to go back to the original us-east-2 bucket (or requires complex separate endpoints), defeating the purpose of MRAP's global write capability and increasing latency for non-US uploads. It also doesn't solve the replication strategy for new uploads.
Community Comment Notes
Comments show a split between CE and AD. Users like BillaRanga correctly identify that bidirectional replication allows uploads to the nearest region, keeping everything in sync. Others like kajiyatta argue the question is vague about where developers are located, leading them to assume the source region (us-east-2) remains the upload point, thus favoring A and D. However, 'minimize latency for developers... near eu-west-2' implies those developers should upload locally, not to us-east-2.
Exam Strategy
When a question mentions 'global' access and 'latency' for both reads and writes, consider S3 Multi-Region Access Points combined with Cross-Region Replication (CRR). Specifically, look for 'bidirectional' or 'multi-region' replication if you need to allow writes from multiple locations. Always check if the solution minimizes application changes; MRAP simplifies this by providing a single DNS name.
Frequently Asked Questions
Why is bidirectional replication required instead of one-way?
Can S3 Multi-Region Access Point handle uploads?
Community Votes
52% of anonymous learners picked answer CE. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 13 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 13
-
BillaRanga 👍 13To keep replication in SYNC across all three regions, we use Bi-directional. Multi-Region Access Point for video streaming and uploads. -> uploads to nearest Low latency region and Bi-directional replication will keep other two regions in SYNC this reducing the upload and streaming latency
-
67a3f49 👍 4There is no information where the upload should be performed. If files will be uploaded to first region then: AD because: A -> content uploaded to the primary bucket in us-east-2 is automatically replicated to the other regions, minimizing latency for users accessing content near those regions. D -> uploads needs to be performed to the first region only and accessed to remaining two Otherwise CE
-
kajiyatta 👍 4This is an example of the kind of joke problem AWS provides. The information needed to derive justification is vague and it is not clear which region the uploading developer will be using. Time spent on these problems is wasted.
-
kbgsgsgs 👍 3They are simply trying to replicate to a new S3 bucket. I don't see why it needs to be bidirectional. Also, since the problem assumes that the content developer with permission is the one uploading, it seems like there needs to be a way to centralize the upload without modifying the application.
-
FlyingHawk 👍 3The data is stored in an Amazon S3 bucket in the us-east-2 Region implies the content developer is in us-east-2 region. If the content developers are in the us-east-2 Region, then the solution is A and D.
Show 8 more comments
-
LeonSauveterre 👍 2I agree with @kbgsgsgs and here's why: What the scenario is about: Currenly, videos are in us, so they're uploaded to us. Then, we want to replicate them to eu and ap. People near eu and ap should be fast delivered with the videos they need. So with "FEWEST changes", all we need is replicate from us to both eu and ap, which is option B. Option C works but not fewest changes. The uploads are directly to us, so option E actually induces more latency. You may argue that if we can upload videos directly to eu/ap, it would be faster. Yes, but it requires modifying the application for both streaming and upload workflows, so much more complicated than option D, and definitely not fewest changes.
-
robotgeek 👍 1 Answered AQuestion does not make a lot of sense with this responses 1) If the goal is to modify the app as little as possible, options D and E don't present much of a difference. If you modify the app for uploads, it will cost you the same to modify it for streaming (even more so with an MRAP, since you only need to change the global upload endpoint, which is a trivial change). 2) It is not suggested that the need is "to upload from anywhere in the world" but rather to copy to other regions for streaming (download), which an MRAP does not do per-se. 3) If the idea of the question is to create an MRAP (D or E) and then set up replication rules in the MRAP (C), it doesn’t make sense to replicate from US-West or from Asia-Pacific, but only the other way around. 4) Option A stands on its own (but it’s a multiple-choice answer), and even though the initial replication latency is slow, uploading video tutorials is not critical. 5) Option B involves unnecessary latency.
-
Scheldon 👍 1AnswerCE From my understanding Video uploads can happen near new regions hence to speed up that operation we need to upload to nearest region, hence I would choose option E, and for the same reason we need to be able to replicate data from any of new region to old one and oposite, hence we we need bidirectional (two-way) replication
-
JA2018 👍 1My personal take: C & D C => Although stem did not specify which region S# bucket the developers will upload their contents, this will allow new contents in 1 S3 bucket to replicate over to the other 2 S3 buckets. D => uploads needs to be performed to the first region only (Closest???) and accessed by remaining two S3 buckets.
-
1166ae3 👍 1Since developer upload video to us-east-2, by configuring one-way replication directly from us-east-2 to eu-west-2 and from us-east-2 to ap-southeast-1, you ensure that each region has the latest data without additional replication hops.
-
sk1974 👍 1I will go with A & D too since that option will require least amount of re-work . In reality , I would have preferred B for the copy option since Ap-Sotheast-1 is closer to eu-west , but , that could involve additional work
-
lenotc 👍 1FEWEST changes to the application D -> MRAP can upload the appropriate S3 bucket C -> two-way -> to worry about anything obs: I believe this question dubious, amphibological
-
Andy_09 👍 3Correct answer CE
Reader comments & corrections
No reader corrections yet — spotted an error or have a note? Share it below.
Related Analysis
Practice All SAA-C03 Questions
Access 120 questions with complete answers and detailed explanations.
View Full SAA-C03 Practice Test →