Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 584 discussion

A spread placement group is a group of instances that are each placed on distinct hardware. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html

A, spread placement group does exactly what is required here. Not C and D, tenancy determines whether the hardware is shared with other customers or not, it has nothing to with your own instances sharing hardware. (On the contrary, dedicated tenancy would spread your EC2 instances across as little nodes as possible.) Not B, accounts have nothing to do with the issue.

Option A: Run the EC2 instances in a spread placement group. Spread Placement Group: This placement group strategy ensures that EC2 instances are distributed across distinct hardware to reduce the risk of correlated failures. Instances in a spread placement group are placed on different underlying hardware, which aligns with the requirement to prevent groups of nodes from sharing the same underlying hardware. This is a good fit for the scenario where you need to ensure high availability and fault tolerance.

Spread – Strictly places a small group of instances across distinct underlying hardware to reduce correlated failures.

dedicated tenancy cannot ensure the instances share the same hardware. So A

Let's assume that you have two groups of instances, group A and group B and you have two physical hardware X and Y. With spread placement group, you can have group A of instances on hardware X and group B on hardware Y but this will not prevent hardware X to host other instances of other customers because your only requirement is to separate group A from group B. On the other hand, the dedicated tenancy means that AWS will dedicate the physical hardware only for you. So, the correct answer is A.

Question is ambiguous and confusing. Is it asking about the EC2 instance of the same application not sharing hardware? or EC2 instance not sharing hardware with other EC2 from other applications?

Spread placement group allows you to isolate your instances on hardware level. Dedicated tenancy allows you to be sure that you are the only customer on the hardware. The correct answer is A.

Def is A: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html

Keywords 'prevent groups of nodes from sharing the same underlying hardware'. Spread Placement Group strictly places a small group of instances across distinct underlying hardware to reduce correlated failures.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html Each instances is placed on seven different racks, each rack has its own network and power source.

Another tricky question, but I would go for A because: Dedicated instances: Dedicated Instances are EC2 instances that run on hardware that's dedicated to a single customer. Dedicated Instances that belong to different AWS accounts are physically isolated at a hardware level, even if those accounts are linked to a single payer account. However, Dedicated Instances might share hardware with other instances from the same AWS account that are not Dedicated Instances. Which is not the desired option. Spread – strictly places a small group of instances across distinct underlying hardware to reduce correlated failures. That's why A.

C is clear.

A When you launch a new EC2 instance, the EC2 service attempts to place the instance in such a way that all of your instances are spread out across underlying hardware to minimize correlated failures. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/placement-groups.html

Spread Placement Group strictly places a small group of instances across distinct underlying hardware to reduce correlated failures.

C is the correct answer. Configuring the EC2 instances with dedicated tenancy ensures that each instance will run on isolated, single-tenant hardware. This meets the requirement to prevent groups of nodes from sharing underlying hardware. A spread placement group only provides isolation at the Availability Zone level. Instances could still share hardware within an AZ.

Option A is the correct answer. It suggests running the EC2 instances in a spread placement group. This solution is cost-effective and requires minimal development effort .