Building Resilient Distributed Systems

Distributed systems fail in interesting ways. Here’s what I’ve learned about building systems that stay up when things go wrong.

Accept That Failures Happen

The first step is acknowledging that failures are inevitable. Design for failure from day one.

Key Patterns

Circuit Breakers

Prevent cascading failures by failing fast:

const breaker = new CircuitBreaker(request, {
  timeout: 3000,
  errorThresholdPercentage: 50,
  resetTimeout: 30000,
});

Retries with Backoff

Implement exponential backoff for transient failures:

async function retryWithBackoff(fn, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (error) {
      const delay = Math.pow(2, i) * 1000;
      await sleep(delay);
    }
  }
  throw new Error('Max retries exceeded');
}

Bulkheads

Isolate components to prevent total system failure.

Observability is Key

You can’t fix what you can’t see. Invest in:

• Distributed tracing
• Structured logging
• Meaningful metrics
• Real-time alerting