Cloud-Native Patterns
Twelve-Factor App
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Codebase: One codebase, many deploys
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Dependencies: Explicitly declare and isolate
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Config: Store in environment
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Backing Services: Treat as attached resources
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Build, Release, Run: Strictly separate stages
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Processes: Execute as stateless processes
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Port Binding: Export services via port
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Concurrency: Scale out via process model
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Disposability: Fast startup and graceful shutdown
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Dev/Prod Parity: Keep environments similar
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Logs: Treat as event streams
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Admin Processes: Run as one-off processes
Resilience Patterns
Circuit Breaker
Prevent cascading failures by failing fast.
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
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
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REST/HTTP
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gRPC
Asynchronous
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Message queues (RabbitMQ, SQS)
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Event streaming (Kafka)
Health Checks
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
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One process per container
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Use multi-stage builds
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Run as non-root user
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Use health checks
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Keep images small