AWS Certified Advanced Networking – Specialty ANS-C00 – Question261

You have been tasked with migrating your company's proprietary massively large dataset sorting application to AWS. The application currently runs on 4 highly spec'd servers that are in a cluster arrangement and runs 24×7, with the average CPU utilisation across any 24hr period being approx 85% – the migration of this cluster once up and running on AWS is expected to run similarly. The servers shuffle data internally and between themselves. Your company's financial performance is entirely dependent on the speed at which it can sort your customers datasets, that is the faster a sorted result can be returned the better your company's bottom line.
Of the choices presented below, select the optimal network configuration that will ensure the best financial results for your company.

A.
Disable Jumbo Frames to ensure better data throughput between instances
B. Enable Jumbo Frames to ensure better data throughput between instances
C. Create an autoscaled group of c4.8xlarge instances – with min 1 and max 4 – this will ensure your operational costs a minimal
D. Configure a CloudWatch Alarm to add more CPUs to the instances when average cluster CPU utilisation breaches 85%

Correct Answer: B

Explanation:

Explanation: Answer C does not meet the brief – the question states that the requirement is to run a cluster of 4 servers 24×7 – and that the average CPU utilisation across any 24hr period is 85% – therefore have an ASG with min 1 and max 4 provides no benefit, and if anything scaling down from 4 machines would impact the speed at which sorting results are returned – and therefore this would affect the company’s bottom line. We know that of the Answers A and B we need to choose one – Answer B best supports our requirements – to move data faster between servers. Answer D is nonsensical – AWS doesn’t support adding or removing CPUs to instances.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/network_mtu.html