Reference library

Reliability & rate limiting

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

3 matches

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 Propagate Context Variables with asyncio in Python

Use Python's ContextVar with asyncio to carry deadline information across concurrent tasks and propagate context automatically.

contextvars asyncio concurrency

Python

import asyncio
from contextvars import ContextVar
from datetime import datetime

deadline = ContextVar("deadline", default=None)

async def worker(name):
    current = deadline.get()
    if current:
        print(f"{name} sees deadline: {current}")
    else:
        print(f"{name} sees no deadline")
    await asyncio.…

13 0 Open

Reliability & rate limiting medium

Saga Compensating Transaction Mock in Python

Simulates a distributed transaction using a saga pattern with compensating actions that roll back steps on failure.

saga transaction compensation

Python

import random
import time


class OrderService:
    def __init__(self):
        self.orders = {}

    def create_order(self, order_id):
        print(f"[Order] Creating order {order_id}...")
        time.sleep(0.1)
        if random.random() < 0.3:  # 30% chance of failure
            raise RuntimeError(f"Order {order…

12 0 Open

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