AWS Solution Architect Associate (SAA-C02) Review Material – Container Management

ECS

• A fully managed container orchestration service that makes it easy for you to deploy, manage, and scale containerized applications.
• Only support Docker containers.
• Tasks and Services:
  • Tasks:
    • A task definition is required to run Docker containers in Amazon ECS which defines:
      • The Docker image to use with each container in your task
      • How much CPU and memory to use with each task or each container within a task
      • The launch type to use, which determines the infrastructure on which your tasks are hosted
      • The Docker networking mode to use for the containers in your task
      • The logging configuration to use for your tasks
      • Whether the task should continue to run if the container finishes or fails
      • The command the container should run when it is started
      • Any data volumes that should be used with the containers in the task
      • The IAM role that your tasks should use
    • A Task is a running container.
    • Can be invoked by CloudWatch Event/Event Bridge.
    • Can autoscale via CloudWatch Metric.
  • Service:
    • Allows you to run and maintain a specified number of instances of Tasks. It is usually used for long-running processes.
    • Can be configured to talk to an ALB
• Manages worker nodes – either an EC2 or Fargate
• 2 Launch Types:
  1. EC2 Launch Type
     • Requires an ASG
     • Requires an agent installed on the EC2 (not required to be installed if used AMI for ECS)
     • Can have it’s private IP or use VPC IP
  2. Fargate
     • Serverless offering. Does not require to provision EC2 instances.
     • Will assign an ENI for each running task.
     • Will use VPC IP.
• Integration with ALB (Dynamic Port Mapping) for EC2 Launch Type. Must allow in Security Group ALB access to all ports. Fargate use fix port (ENI)
• Requires 2 types of IAM Roles:
  • EC2 Instance Profile:
    • Used by the ECS agent to make AWS API calls (e.g. CloudWatch, ECS service)
  • ECS Task
    • Used by the ECS task to make AWS API calls.
    • Good practice to use different roles for each task,
• Normally use EFS for task volume.
• Rolling Update
  • Uses Minimum Healthy Percent and Maximum Healthy Percent
  • Minimum Healthy Percent – the minimum number of tasks that must be running as a percentage of the total.
  • Maximum Healthy Percent – the maximum number of tasks that must be running as a percentage of that total
  • Example 1:
    • 4 Running Task; Minimum= 50% Maximum = 100%
      • Cannot add new version before terminating the old version since Maximum = 100% (i.e. current running task is already 100%)
      • Can only terminate 2 instances for replacement (50 % of 4) before adding a new version.
    • 4 Running Task; Minimum= 50% Maximum = 150%
      • Can add additional 2 instances since the Maximum is 150% before terminating the old version (so total is now 6)
      • Can terminate 2 instances and replace them with a new version so we can maintain 4 running tasks.

EKS

• A managed Kubernetes service
• 2 Launch Types:
  1. EC2 Launch Type
     • Requires an ASG
     • Requires an agent installed on the EC2 (not required to be installed if used AMI for ECS)
     • Can have it’s private IP or use VPC IP
  2. Fargate
     • Serverless offering. Does not require to provision EC2 instances.
     • Will assign an ENI for each running task.
     • Will use VPC IP.