Retry Logic

ELI5 — The Vibe Check

Retry Logic automatically retries failed requests instead of giving up on the first failure. But done wrong, retries cause thundering herds. The secret: exponential backoff with jitter. Wait 1s, then 2s, then 4s — plus some randomness so all clients don't retry at the same time.

Real Talk

Retry logic handles transient failures by re-attempting operations with strategies like fixed delay, exponential backoff, and jitter. Key considerations: idempotency (safe to retry), max attempts, retry-able error codes, and circuit breaking to prevent cascading failures. Libraries like axios-retry and tenacity simplify implementation.

Show Me The Code

async function fetchWithRetry(url, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fetch(url);
    } catch (err) {
      if (i === maxRetries - 1) throw err;
      const delay = Math.pow(2, i) * 1000 + Math.random() * 1000;
      await new Promise(r => setTimeout(r, delay));
    }
  }
}

When You'll Hear This

"Exponential backoff with jitter prevents all clients from retrying at the same moment." / "Only retry idempotent operations — retrying a payment could charge the customer twice."