Reference library

Reliability & rate limiting

Retries, exponential backoff, circuit breakers, token buckets, and idempotent handlers.

5 matches

How to Cap Retry Attempts in Python with a Decorator

Build a reusable retry decorator that caps attempts, adds delays, and lets flaky services fail fast instead of hanging.

import random
from functools import wraps
from time import sleep


def retry(max_attempts, delay=0.1):
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            attempts = 0
            while attempts < max_attempts:
                try:
                    return func(*args, **kw…

13 0 Open

Reliability & rate limiting medium

How to Implement a Circuit Breaker in Python

A Python dataclass that provides circuit breaker logic with closed, open, and half-open states to fail fast on repeated errors.

circuit-breaker resilience fault-tolerance

Python

from dataclasses import dataclass
from datetime import datetime, timedelta
import time


@dataclass
class CircuitBreaker:
    failure_threshold: int = 3
    timeout_seconds: float = 5.0
    failures: int = 0
    state: str = "closed"
    last_failure: datetime = None

    def call(self, func):
        if self.state ==…

15 0 Open

Reliability & rate limiting medium

How to Simulate an Outbox Pattern with Reliable Retry in Python

This code implements a mock outbox pattern with records, delivery attempts, and retries to simulate reliable message publishing.

outbox retry messaging

Python

import time
import itertools

class Outbox:
    def __init__(self):
        self._records = []
        self._seq = itertools.count(1)

    def publish(self, topic, payload):
        record = {
            "id": next(self._seq),
            "topic": topic,
            "payload": payload,
            "status": "pending"…

14 0 Open

Reliability & rate limiting medium

How to retry idempotent operations with a mock in Python

Wrap a flaky idempotent operation in a retry loop with exponential backoff, and use unittest.mock to deterministically test the str's behavior.

retry backoff mock

Python

import random
import time
from unittest.mock import Mock


def idempotent_operation(value):
    """Simulate an idempotent operation that sometimes fails."""
    if random.random() < 0.6:  # 60% failure rate
        raise ConnectionError("Temporary failure")
    return value * 2


def retry_with_backoff(operation, max_…

14 0 Open

Reliability & rate limiting medium

Retry with Exponential Backoff and Jitter in Python

A decorator-style retry wrapper that retries a flaky function with exponential backoff plus random jitter, then raises after the last attempt fails.

retry backoff jitter

Python

import random
import time

def retry_with_backoff(func, max_retries=3, base_delay=0.5, max_jitter=0.1):
    for attempt in range(max_retries + 1):
        try:
            return func()
        except Exception as e:
            if attempt == max_retries:
                raise
            delay = base_delay * (2 ** at…

14 0 Open

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