Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 5 discussion

Concurrent or at the same time key word for EFS

Ebs doesnt support cross az only reside in one Az but Efs does, that why it's c

The answer is C. Copy the data from both EBS volumes to Amazon EFS. Modify the application to save new documents to Amazon EFS. The current architecture is using two separate EBS volumes, one for each EC2 instance. This means that each instance only has a subset of the documents. When a user refreshes the website, the Application Load Balancer will randomly direct them to one of the two instances. If the user's documents are not on the instance that they are directed to, they will not be able to see them.

To ensure that users see all of their documents at once, the solutions architect should propose Option C: Copy the data from both EBS volumes to Amazon EFS. Modify the application to save new documents to Amazon EFS. Option C involves copying the data from both EBS volumes to Amazon Elastic File System (EFS), and modifying the application to save new documents to EFS. Amazon EFS is a fully managed, scalable file storage service that allows you to store and access files from multiple EC2 instances concurrently. By moving the data to EFS and modifying the application to save new documents to EFS, the application will be able to access all of the documents from a single, centralized location, ensuring that users see all of their documents at once. Overall, Option C is the most effective solution for ensuring that users see all of their documents at once.

Keyword: second EC2 instance and EBS volume. They could see one subset of their documents or the other, but never all of the documents at the same time. EBS: attached to one instance (special EBS io1, io2 can attached to multiple instances but not much) EFS: can attached to multiple instances A: Incorrect - EBS volumes don't have function to copy data from running EBS volume to running EBS volume. B: Incorrect - We can use sticky session to forward same user to the same server but when user lose the session the user might be forward to another server. C: Correct - Because 2 instance now point to one EFS data storage, user will see both data. D: Incorrect - We only use Traffic Mirroring to sent request to both servers. Application Load Balancer don't support send request to both servers because it's design it balance workload between server. And also ALB cannot combine document from both servers and return.

Option A is not a good solution because copying data to both volumes would not ensure consistency of the data. Option B would require the Load Balancer to have knowledge of which documents are stored on which server, which would be difficult to maintain. Option C is a viable solution, but may require modifying the application to use Amazon EFS instead of EBS. Option D is a good solution because it would distribute the requests to both servers and return the correct document from the correct server. This can be achieved by configuring session stickiness on the Load Balancer so that each user's requests are directed to the same server for consistency. Therefore, the correct answer is D.

Ans C. Altho' A could do it, it would require a manual operation; the clue is "better scalability and availability" - EFS does that automatically

Correct Answer is C

C is correct answer.

C for sure

using Amazon EFS to provide a shared storage solution ensures that both EC2 instances can access the same documents, which resolves the issue of users seeing different subsets of documents depending on which instance they are connected to.

C is Correct whereas the purpose of Amazon EFS is to provide a scalable, shared, and fully managed file storage solution that seamlessly integrates with AWS services and meets the performance, availability, and durability requirements of modern applications.

The alternative is to use Aurora or DynamoDB with master-slave replication, otherwise EFS is the most logical.

EBS volumes must be in the same AZ as the instances they are attached to. So you cannot share an EBS across AZs. Unless you plan to have two separate volumes in each AZ, the simpliest solution is to use EFS as a shared file system that can be used across both AZs

If the idea is to keep documents in different places, then the only solution here is a file sharing system, EFS in this case

ABD are not even possible without further deails C is EFS which is shared volume.

Answer-c