Cloud-Native Patterns
Twelve-Factor App
- •Codebase: One codebase, many deploys
- •Dependencies: Explicitly declare and isolate
- •Config: Store in environment
- •Backing Services: Treat as attached resources
- •Build, Release, Run: Strictly separate stages
- •Processes: Execute as stateless processes
- •Port Binding: Export services via port
- •Concurrency: Scale out via process model
- •Disposability: Fast startup and graceful shutdown
- •Dev/Prod Parity: Keep environments similar
- •Logs: Treat as event streams
- •Admin Processes: Run as one-off processes
Resilience Patterns
Circuit Breaker
Prevent cascading failures by failing fast.
typescript
class CircuitBreaker {
private failures = 0;
private lastFailure?: Date;
async call<T>(fn: () => Promise<T>): Promise<T> {
if (this.isOpen()) {
throw new Error('Circuit is open');
}
try {
const result = await fn();
this.reset();
return result;
} catch (error) {
this.recordFailure();
throw error;
}
}
}
Retry with Backoff
typescript
async function withRetry<T>(
fn: () => Promise<T>,
maxRetries = 3
): Promise<T> {
for (let i = 0; i < maxRetries; i++) {
try {
return await fn();
} catch (error) {
if (i === maxRetries - 1) throw error;
await sleep(Math.pow(2, i) * 1000); // Exponential backoff
}
}
}
Bulkhead
Isolate failures to prevent system-wide impact.
Service Communication
Synchronous
- •REST/HTTP
- •gRPC
Asynchronous
- •Message queues (RabbitMQ, SQS)
- •Event streaming (Kafka)
Health Checks
typescript
app.get('/health', (req, res) => {
res.json({ status: 'healthy' });
});
app.get('/ready', async (req, res) => {
const dbHealthy = await checkDatabase();
const cacheHealthy = await checkCache();
if (dbHealthy && cacheHealthy) {
res.json({ status: 'ready' });
} else {
res.status(503).json({ status: 'not ready' });
}
});
Container Best Practices
- •One process per container
- •Use multi-stage builds
- •Run as non-root user
- •Use health checks
- •Keep images small