Spread placement group

[ray712]

Not sure that the answer is correct in this scenario (spread allows only 7 instances)

A tech lead plans to deploy a highly available web application on 12 Amazon EC2 instances. She is required to deploy each of the instances on distinct underlying hardware.

What solution should the tech lead implement to meet the requirements?

Use the cluster placement group when launching the EC2 instances and place them in a single region.  
Deploy the instances in multiple regions and place them into a partition placement group.  
Use the spread placement group when launching the EC2 instances and deploy them in multiple regions.  
Deploy the instances in a single region and place them into a spread placement group.

Hence, the correct answer is: Deploy the instances in a single region and place them into a spread placement group.

[wayne-c]

Hi ray712,

Thanks for your inquiry.

A spread placement group can span multiple Availability Zones in the same Region. You can have a maximum of seven running instances per Availability Zone per group.

Reference: Placement groups – Amazon Elastic Compute Cloud

This means that you can deploy the 12 instances in the same region. I hope this helps.

Let us know if you need further assistance. The Tutorials Dojo team is dedicated to help you pass your AWS exam on your first try!

[ray712]

Thank you for the answer but … the question is :

“web application on 12 Amazon EC2 instances. She is required to deploy each of the instances on distinct underlying hardware”

So it is not possible to put 12 instances over 7 spread placement group ((with distinct underlaying hw).

=> It should be a partition group.

Am I wrong ?

[chris-wayne]

Hi ray712,

Thanks for your response.

The keyword in this question is to place the instances in distinct underlying hardware.

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

Partition placement group – spreads your instances across logical partitions such that groups of instances in one partition do not share the underlying hardware with groups of instances in different partitions.

Reference: Placement groups – Amazon Elastic Compute Cloud

In a partition placement group, instances in the same partition will share the same hardware. Only instances on different partition will not share underlying hardware.

A spread placement group can span multiple Availability Zones in the same Region. You can have a maximum of seven running instances per Availability Zone per group. This means that you can deploy the 12 instances in the same region on different AZs.

Now, since you need to deploy the each of the instances on distinct underlying hardware, spread placement group best fits the criteria.

There is a requirement also to make sure that the web application is highly available. Having instances on different AZs will make the web application highly available.

Let us know if you need further assistance. The Tutorials Dojo team is dedicated to help you pass your AWS exam on your first try!

Regards,

Wayne @ Tutorials Dojo