Distributed Systems Patterns

# Distributed Systems Patterns

Distributed systems are hard. These patterns make them manageable.

## Resilience Patterns

**Circuit Breaker**

Stop calling failing services. Give them time to recover.

**Retry with Backoff**

Try again, but not immediately. Exponential backoff prevents thundering herds.

**Bulkhead**

Isolate resources to prevent cascade failures.

## Data Patterns

**Saga Pattern**

Distributed transactions via compensating actions.

**CQRS**

Separate read and write models for optimal performance.

**Event Sourcing**

Store changes, not state. Enables powerful audit and replay.

## Communication Patterns

**API Gateway**

Single entry point for clients. Handles routing, auth, rate limiting.

**Service Mesh**

Infrastructure layer for service-to-service communication.

## The Fallacies

Never assume:

- The network is reliable

- Latency is zero

- Bandwidth is infinite

- The network is secure

Plan for failure. It's not if, it's when.