Q100 — AWS SOA-C02 Ch.1

Question 100 of 100 | ← Chapter 1

Users are periodically experiencing slow response times from a relational database. The database runs on a burstable Amazon EC2 instance with a 350 GB General Purpose SSD (gp2) Amazon Elastic Block Store (Amazon EBS) volume. A SysOps administrator monitors the EC2 instance in Amazon CloudWatch and observes that the VolumeReadOps metric drops to less than 10% of its peak value during the periods of slow response. What should the SysOps administrator do to ensure consistently high performance?

• A. Convert the gp2 volume to a General Purpose SSD (gp3) EBS volume.
• B. Convert the gp2 volume to a Cold HDD (sc1) EBS volume.
• C. Convert the EC2 instance to a memory optimized instance type.
• D. Activate unlimited mode on the EC2 instance. ✓

Correct Answer: D. Activate unlimited mode on the EC2 instance.

Explanation

gp2 EBS卷的性能与其容量相关，容量越大基线性能越高。当IO需求超过基线时，使用IO积分，积分耗尽后性能降至基线。题目中观察到读操作骤降，说明积分耗尽导致性能受限。AWS EBS的无限模式允许在需要时持续突破IO限制，无需依赖积分机制。选项D激活无限模式可避免积分耗尽引发的性能波动，保持高吞吐量。选项A转换为gp3虽提供更高基线但需手动调整；选项B的sc1是低成本冷存储；选项C内存优化实例不直接影响存储IO。来源：Amazon EBS卷类型文档关于突发性能与无限模式的说明。