Design High-Performance Architectures

Question 1

How can web instances in public subnet connect to databases in private subnet

Answer 1

Create security groups for web instances in public subnet.
Allow outbound traffic to the DBServerSG for appropriate ports(1433, 3306, etc.)
Create security group for database(s) in private.
Allow inbound traffic to web security group on appropriate port (1433, 3306, etc.)

Question 2

Design migration of on-premises Docker/Kubernetes orchestration to AWS and not manage underlying infrastructure

Answer 2

AWS Fargate with Amazon EKS
Amazon EKS integrates Kubernetes with AWS Fargate by using controllers that are built by AWS using the upstream, extensible model provided by Kubernetes.
https://docs.aws.amazon.com/eks/latest/userguide/fargate.html

Question 3

An Amazon Machine Image (AMI) includes the following:

Answer 3

One or more Amazon Elastic Block Store (Amazon EBS) snapshots, or, for instance-store-backed AMIs, a template for the root volume of the instance (for example, an operating system, an application server, and applications).

Launch permissions that control which AWS accounts can use the AMI to launch instances.

A block device mapping that specifies the volumes to attach to the instance when it’s launched.

Question 4

What is Elastic Fabric Adapter (EFA)?

Answer 4

Network device that you can attach to your Amazon EC2 instance to accelerate High Performance Computing (HPC) and machine learning applications.

Question 5

EFA features and benefits

Answer 5

Achieve app performance of an on-premises HPC cluster, with scalability, flexibility and elasticity of cloud

Provides lower and more consistent latency/higher throughput than TCP transport
Enhances inter-instance performance communication critical for scaling HPC & ML apps.
Optimized for AWS network

Question 6

EFA limitations

Answer 6

The OS-bypass capabilities of EFAs are not supported on Windows instances. If you attach an EFA to a Windows instance, the instance functions as an Elastic Network Adapter, without the added EFA capabilities.

Question 7

Is EFA just another ENA?

Answer 7

It provides all of the functionality of an ENA, with an additional OS-bypass functionality. OS-bypass is an access model that allows HPC and machine learning applications to communicate directly with the network interface hardware to provide low-latency, reliable transport functionality.

Question 8

Can CloudFront cache dynamic content

Answer 8

sort of?

…various other optimization such as persistent TCP connections to the origin, SSL enhancements such as Session tickets and OCSP stapling helps in improving the performance even for non-cacheable, dynamic content.

…Extensive options for cookie and querystring handling, cache key modification , CDN and client-side cache-control allow for maximizing what content is cached, what comes directly from the origin.

https://aws.amazon.com/cloudfront/dynamic-content/