Ref: https://learn.cantrill.io/courses/1820301/lectures/41301394

• Summary:
• Contents:

Amazon EventBridge - Overview and Architecture

Diagram: https://github.com/acantril/aws-sa-associate-saac03/blob/main/1600-SERVERLESS_and_APPLICATION_SERVICES/00_LEARNINGAIDS/EventBridge-1.png

• 🔧 Manage system events in your AWS account
  • Events describe changes in AWS products & services (e.g. EC2 instance terminated)
  • Provides:
    • Event visibility (near-real-time stream of events = Event Bus)
    • Event delivery to targets/destination
  • Can support event-driven architectures (EDAs) in AWS
• Event Bus: contains a stream of events ← monitored by EventBridge
  • Default Event Bus: present in any AWS account, contains all system events in account
    • Implicit, not really exposed in the UI
  • EventBridge can configure additional event buses → manage events from outside the account, from external services, etc.
• Basic job/architecture: “If X happens, or at Y time(s)… send info to Z”
  • X = generated event from a supported AWS service (event producer)
  • Y = certain time/time periods, traditionally specified using Unix CRON format (scheduled events)
    • 💡 EventBridge Scheduler has a more modern UI that can allow you to set a schedule in a friendlier manner
  • Z = supported target AWS service to deliver the event to (event consumer)
• Rules match incoming events (or schedules) → Event Pattern Rule OR Schedule Rule
  • When event/schedule matches, events are routed to 1+ targets (e.g. Lambda)
• Events delivered as JSON structures → their data can be used by the targets
  • e.g. if EC2 instance changes state, its event contains instance ID, newState, timestamp…

CloudWatch Events

• 🔧 Amazon EventBridge has a superset of the functionality of CWEvents
  • 💡 CWEvents was historically the place for event management… but it has been phased out by EventBridge, which contains more functionality → going to CWEvents now just redirects to EventBridge
• EventBridge and CWEvents use the same underlying APIs and basic architecture
• ❗ While it was still accessible, CWEvents could ONLY monitor the default event bus in the account
  • EventBridge can also handle events from 3rd-parties as well as custom apps, by configuring additional event buses