Amazon EventBridge is a serverless event bus service that enables you to build event-driven architectures by connecting applications using events. It serves as a central hub for routing events between AWS services, integrated SaaS applications, and your custom applications.
Key concepts include:
…Amazon EventBridge is a serverless event bus service that enables you to build event-driven architectures by connecting applications using events. It serves as a central hub for routing events between AWS services, integrated SaaS applications, and your custom applications.
Key concepts include:
**Event Bus**: A pipeline that receives events. EventBridge provides a default event bus for AWS services, plus you can create custom event buses for your applications or partner event buses for SaaS integrations.
**Events**: JSON objects representing state changes or occurrences. Each event contains metadata like source, detail-type, and the actual event data in the detail field.
**Rules**: Define which events to capture and where to send them. Rules use event patterns (JSON-based filtering) to match incoming events and route them to one or more targets.
**Targets**: Destinations for matched events, including Lambda functions, Step Functions, SQS queues, SNS topics, API Gateway endpoints, and many other AWS services.
**Event Patterns**: JSON structures that filter events based on attributes. You can match on exact values, prefixes, numeric ranges, or use content-based filtering.
**Schema Registry**: Automatically discovers and stores event schemas, enabling code generation for type-safe event handling in your applications.
**Archive and Replay**: Store events for later analysis and replay them to an event bus for debugging or reprocessing scenarios.
Common use cases include:
- Decoupling microservices communication
- Responding to AWS resource state changes
- Building real-time data processing pipelines
- Integrating third-party SaaS applications
- Implementing fan-out patterns
For the AWS Developer Associate exam, understand how to create rules with event patterns, configure targets, implement error handling with dead-letter queues, and leverage EventBridge for loose coupling between application components in serverless architectures.
Amazon EventBridge for Event-Driven Patterns
Why is Amazon EventBridge Important?
Amazon EventBridge is a cornerstone service for building modern, loosely coupled, event-driven architectures on AWS. It enables applications to react to changes in state across AWS services, SaaS applications, and custom applications. For the AWS Developer Associate exam, understanding EventBridge is essential because it represents AWS's recommended approach for building scalable, maintainable serverless applications.
What is Amazon EventBridge?
Amazon EventBridge is a serverless event bus service that makes it easy to connect applications using data from your own applications, integrated Software-as-a-Service (SaaS) applications, and AWS services. It was formerly known as Amazon CloudWatch Events and has been significantly enhanced with additional features.
Key Components:
Event Bus: A router that receives events and delivers them to targets. There are three types: • Default event bus - Receives events from AWS services • Custom event buses - For your own applications • Partner event buses - For SaaS partner integrations
Events: JSON objects that represent a change in state. They contain fields like source, detail-type, and detail.
Rules: Match incoming events and route them to targets. Rules use event patterns (JSON-based) or schedules.
Targets: AWS services or resources that process events (Lambda, SQS, SNS, Step Functions, API Gateway, and more).
How Does EventBridge Work?
1. Event Production: An event source generates an event when something changes 2. Event Ingestion: The event is sent to an event bus via the PutEvents API 3. Rule Evaluation: EventBridge evaluates the event against all rules on the bus 4. Event Routing: Matching rules route the event to their configured targets 5. Event Processing: Targets receive and process the event
Event Pattern Matching:
Event patterns are JSON objects that define which events match a rule. They support: • Exact matching on field values • Prefix matching using the prefix keyword • Numeric matching (equals, range) • IP address matching using CIDR notation • Exists matching to check if a field is present • Anything-but matching for exclusions
Schema Registry:
EventBridge includes a schema registry that stores event schemas. It can automatically discover schemas from events on your bus and generate code bindings for popular programming languages.
Archive and Replay:
You can archive events and replay them later. This is useful for: • Testing new event consumers • Recovering from failures • Debugging event-driven applications
Cross-Account and Cross-Region:
EventBridge supports sending events across AWS accounts and regions, enabling distributed architectures and event aggregation patterns.
Exam Tips: Answering Questions on Amazon EventBridge for Event-Driven Patterns
1. Know When to Choose EventBridge: • Questions about decoupling microservices with events → EventBridge • Scenarios requiring reaction to AWS service state changes → EventBridge • Integration with third-party SaaS applications → EventBridge Partner integrations • Scheduled tasks or cron-like functionality → EventBridge Scheduler rules
2. Understand Event Pattern Syntax: • Event patterns match on the structure of events, not regex • All conditions in a pattern must match (AND logic) • Array values mean any value can match (OR logic) • Remember content filtering operators: prefix, numeric, cidr, exists, anything-but
3. Compare with Other Services: • SNS vs EventBridge: Use EventBridge for content-based filtering and complex routing; SNS for simple pub/sub • SQS vs EventBridge: SQS is for queuing messages; EventBridge is for event routing • Step Functions vs EventBridge: Step Functions orchestrate workflows; EventBridge choreographs through events
4. Remember Key Limits: • PutEvents supports up to 10 entries per request • Event size limit is 256 KB • Up to 300 rules per event bus (soft limit) • Up to 5 targets per rule
5. Identify Common Patterns: • Fan-out: One event triggers multiple targets • Event replay for debugging or recovery scenarios • Cross-account event sharing for multi-account architectures • Dead-letter queues for handling failed event delivery
6. API Gateway Integration: • EventBridge can target API Gateway endpoints • Useful for triggering HTTP endpoints in response to events
7. Input Transformation: • Rules can transform event data before sending to targets • Use input paths and input templates to customize payloads
Common Exam Scenarios:
• Building loosely coupled applications that respond to S3 object uploads • Triggering Lambda functions based on EC2 state changes • Creating scheduled tasks that run at specific intervals • Integrating with partner SaaS applications for event processing • Implementing event sourcing patterns with archive and replay