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A company hosts a web application service in the AWS eu-west-1 region. The application serves high-resolution weather maps to users. The maps are updated frequently which are stored in an Amazon S3 bucket along with the static web contents. The web application is behind an Amazon CloudFront distribution. The company has expanded and now provides the same service to North American users. The new users report that their viewing experience with the weather maps is inconsistent and slow at times.
Which of the following steps can be implemented to provide consistent performance to the users? (Select TWO.)
As part of this question, rather than using Lambda@Edge directly and sending the users to send the traffic from US users to new US S3 bucket, the correct answer is shown to be using a Global Accelerator and putting it behind the CloudFront and then use Lambda@Edge. What value would Global Accelerator bring here, as compared to the using normal CloudFront, as both use the same edge location network.
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Hi vikas-12
Thank you for your feedback.
We have a comparison here on the difference between AWS Global Accelerator and Amazon CloudFront.
Which one to choose is depending on the use-case scenario.
Both CloudFront and Global accelerator use an Edge location closest to the user. However, the next step for the request is how they would differ.
CloudFront will inspect the request and check if the request is cached, if it is not, then it will query the Origin server to fetch the response to that request.
Global accelerator on the other hand does not cache anything. Once the request is received, it is immediately sent to the AWS high-speed backbone network going to the server. This is a consistently fast network.
I think the key to this question is stated on “frequently updated” which means there is less caching and more fetching on the server. Therefore, using AWS Global Accelerator to improve latency response, and provide consistently high network performance.
Hope this helps.
Let us know if you need further assistance. The Tutorials Dojo team is dedicated to helping you pass your AWS exam!
Regards,
Kenneth Samonte @ Tutorials Dojo
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Even if they are frequently updated, they are still static assets. And can be cached (may be for lesser time period); consequent requests will have lower latency.
Cloudfront also uses Amazon’s backbone network to reach the origin. If we have already decided to replicate the bucket in us-east-1, if CloudFront is giving latency to users in North America even in this case, then CloudFront needs improvement, it defeats it’s purpose. Adding another hop with global accelerator is not going to help.
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I also doubt the correctness of adding Global Accelerator. For example, we have not considered cost and how it compares with cost for transfer acceleration as the solution with transfer acceleration is technically correct but discarded as it is more expensive.
S3 CRR is a good solution but asynchronous replication meaning the user experience may not be guaranteed. Is that acceptable? If not, this option should not be considered and one should redirect all the users to the same S3 bucket via transfer acceleration / global accelerator.
Hence, the correct options really depend on additional factors that are not given in the question. The options shown as correct are correct in a specific scenario and not generally correct.
Thanks.
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