9. Containers

Question 1

Three reasons tightly-coupled monolithic architectures are bad.

Answer 1

• Less resilient
• Harder to scale
• Slower feature delivery (1)

(1): Conway’s Law - https://en.wikipedia.org/wiki/Conway%27s_law

Question 2

Best alternative to monoliths?

Answer 2

Microservices approach

Question 3

Describe microservices approach

Answer 3

Based on a **collection of small services **:

• Specialized for a single purpose
• Self-contained code and functionality
• Loosely coupled via load-balancing
• Well-defined APIs for communication
• Autonomous deployment and scaling

https://docs.aws.amazon.com/whitepapers/latest/microservices-on-aws/simple-microservices-architecture-on-aws.html

Question 4

How to manually run containers on an EC2 instance?

Answer 4

• Deploy an EC2 instance
• Install a container runtime
• Build & run containers

Question 5

The 3 components of a managed container solution?

Answer 5

• Container registry
• Orchestration tool (control plane)
• Container hosting (data plane)

Question 6

What is a container registry?

Answer 6

A collection of repositories that store container images.

Question 7

What is the AWS container registry service called?

Answer 7

Amazon ECR

Question 8

What container orchestration services does AWS offer?

Answer 8

• ECS
• EKS

Question 9

When to use ECS vs. EKS?

Answer 9

• ECS - Best if you are primarily AWS.
• EKS - Best for interoperating with on-prem or other cloud providers.

Question 10

What container hosting options does AWS offer?

Answer 10

• EC2
• Fargate

https://docs.aws.amazon.com/AmazonECS/latest/developerguide/launch_types.html

Question 11

For ECS, the hosting options are also called:

Answer 11

Launch type

Because that is the type of hosting resource the container will be *

Question 12

Advantages of using EC2 clusters for hosting containers?

Answer 12

• Control over instance type
• Usually more cost effective

EC2 is more cost effective unless you run a very small number of containers per application
(See: https://docs.google.com/spreadsheets/d/1th6E9N96IlKpmoFyQivPkBAdRvFzr4zlseB4ZzI9-hQ/edit?usp=sharing)

Question 13

Advantages of using Fargate for hosting containers?

Answer 13

• Zero management of host resources

Question 14

What are the key components of ECS?

Answer 14

• Services - your applications
• Tasks - container instances
• Cluster EC2 host cluster (optional)
• ECR Registry

Question 15

Four benefits of ECS?

Answer 15

• Service discovery
• AWS integrations
• Flexible hosting (EC2/Fargate)
• CI/CD workflows

Service Discovery: https://docs.aws.amazon.com/AmazonECS/latest/developerguide/service-discovery.html

Question 16

What is EKS?

Answer 16

Amazon’s managed Kubernetes service

Question 17

What version of Kubernetes does EKS run?

Answer 17

The latest open-source version

Question 18

How does EKS provide control plane reliability?

Answer 18

• EKS runs 3 managment nodes, one in each AZ.
• Unhealthy managment nodes are automatically replaced.
• Automated version upgrades & patching

Question 19

What is AWS Fargate?

Answer 19

• Another compute resource type for hosting containers
• No management of EC2 clusters required