ECS 개념 정리

ECS란?

• Fully managed container orchestration service
• Launch compute options
  • Fargate
    • serverless container compute engine
  • AWS Regions
    • same geographical area
  • AWS Local Zones
    • An extension of Region. Suited to customers who need the ability to place resources in multiple locations closer to end users
  • AWS Wavelength
    • Ultra-low-latency mobile edge computing. 5G apps, interactive and immersive experinces, connected vehicles.
  • AWS Outposts
    • A family of fully managed solutions delivering AWS infrastructure and services to virtually any on-premises or edge location for a truly consistent hybrid experience.
  • Amazon ECS Anywhere
    • helps customers launch containers on their self-managed compute outside of AWS
  • ECS instances

ECS의 문제점

• Container scheduling
• Container lifecycle management
  • 다운타임 없이 새로운 container로 변경할 수 있을지, 문제 발생 시 어떻게 탐지 할지
• Container runtime needs
  • LB, service discovery, auto scaling, secret handling

ECS의 장점

• Fully managed control plane
• Fargate serverless compute engine integration
• Native integrations with valuable AWS services or capabilities
• Proven performance and scale
• Powerful simplicity
• No charge
  • EC2 instance나 EBS volume등 resource 사용량에 대해서만 과금

Fargate

• serverless compute engine for containers that works with both ECS and EKS
• Seamless Scaling
• has its own boundary and does not share the underlying kernel, CPU, memory, ENI

ECS on EC2 VS Fargate

• Networking
  • EC2는 awsvpc, bridge, none 사용
  • Fargate는 awsvpc만 사용
• Rightsize Fargate configurations
• Optimize spending with compute options
  • Fargate에서 spot instance사용 가능
  • graviton2 + fargate + compute savings plan layering
• EC2에 비해 Fargate가 덜 customizable 함
• Fargate, kernel-level, OS-level customizing 이 어려움
• Partner integration 측면에서도 EC2 daemon으로 가능 but fargate는 sidecar 패턴으로

Service Scheduler

• 오래 실행되는 stateless 한 서비스나 application에 적합
• 2가지 전략
  • REPLICA: desired number of tasks across your cluster. AZ에 분산. Task placement decision을 customize하여 분산 전략 및 제한을 구성 가능
  • DAEMON: Fargate에서는 미지원. EKS 의 daemonset과 유사. Fargate에서는 X

Manually Running task

• RunTask: 실행되고 끝나는 batch job에 적합. ex) process가 queue에 쌓일때. default task placement strategy로 한 인스턴스에 task 몰리는 것 방지.

Cron-like scheduling

• EventBridge Scheduler로 스케줄링 가능.

Custom Scheduling

• StartTask API와 같은 3rd party scheduler 도 사용 가능.

Service Discovery

Running Windows Containers with ECS Fargate

• Unlike Linux applications that log to STDOUT, Windows applications log to Windows locations such as ETW, Event Log, and custom log files
• Microsoft Log Monitor is an open source tool built by Microsoft
• to send IIS logs and System Logs to a STDOUT pipeline created by Log Monitor
• logs are automatically captured by awslogs driver and sent to CloudWatch logs
• Monitoring performance with CloudWatch Container Insights
  • Container Insights collects data as performance log events using embedded metric format
  • These performance log events are entries that use a structured JSON schema that enables high-cardinality data to be ingested and stored at scale