Event-Driven Architecture

Kind: style

Layer: Execution Core

Aliases: EDA

Record: architecture:event-driven-architecture

Severity: contextual

Scope: service, integration, system

Canonical: Ontology

A convention of connecting services through published events, with each consumer reacting independently of the producer.

Listed in Architecture principles, after Polymorphism and before Publish/Subscribe Pattern.

Requires

• Events
• Message Contract
• Idempotency

Reinforces

• Low Coupling
• Asynchronous Communication

Enables

• Event Sourcing
• Command Query Responsibility Segregation (CQRS)
• Saga Pattern

Conflicts with

• Hidden Temporal Coupling

In tension with

• Debuggability
• Strong Consistency

Tensions

• Event-Driven Architecture / Debuggability
• Event-Driven Architecture / Strong Consistency

Violated by

• Non-Idempotent Operation
• Ad-Hoc Payloads

Refactored by

• Domain Events
• Outbox Pattern
• Consumer-Driven Contract Tests

Severity

• contextual

Category

• Event / Messaging / Asynchronous Architecture

Required by

• Choreography

Reinforced by

• Event Bus
• Observer Pattern

Linked from

• Execution joins the halves
• Domain Architecture
• Control / Coordination / Centralization
• Core Modular Design
• Event / Messaging / Asynchronous Architecture
• Behavioral Patterns
• Transactions / State / Concurrency
• Contracts / Interfaces / Compatibility
• Core Vocabulary
• Error Handling / Resilience
• Event Messaging Async
• Quality Attributes
• Severity levels
• The resolutions