AWS Certified Solutions Architect – Associate (SAA-C02) — Question 465

A solutions architect is deploying a distributed database on multiple Amazon EC2 instances. The database stores all data on multiple instances so it can withstand the loss of an instance. The database requires block storage with latency and throughput to support several million transactions per second per server.
Which storage solution should the solutions architect use?

Answer options

• A. EBS Amazon Elastic Block Store (Amazon EBS)
• B. Amazon EC2 instance store
• C. Amazon Elastic File System (Amazon EFS)
• D. Amazon S3

Correct answer: B

Explanation

Amazon EC2 instance store provides temporary block-level storage with very high random I/O performance and low latency, which is ideal for distributed databases that handle replication at the application level to survive instance loss. Amazon EBS, while persistent, cannot match the extreme, low-latency IOPS performance of NVMe-based instance store required for millions of transactions per second. Amazon EFS is a shared file system and Amazon S3 is object storage, neither of which meets the block storage requirement.