Reference library

Reliability & rate limiting

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

4 matches

How to Implement Hedged Requests in Python

This code demonstrates a hedged request pattern using threading, which sends duplicate calls and returns the first result that arrives within a timeout.

hedged-requests threading timeout

Python

import time
from unittest.mock import Mock

def hedged_request(call, timeout=0.05):
    """Execute two duplicate calls, return first result within timeout."""
    result_container = {}

    def run_and_store():
        result_container['result'] = call()
        result_container['done'] = True

    # Simulate slow cal…

16 0 Open

Reliability & rate limiting easy

How to Implement Message Visibility Timeout Renewal in Python

Simulate queue message visibility control with timeout renewal using a simple Python class that tracks received time and visibility state.

visibility-timeout queue sqs

Python

import time
import uuid

class Message:
    def __init__(self, body, visibility_timeout=30):
        self.body = body
        self.visibility_timeout = visibility_timeout
        self.receipt_handle = str(uuid.uuid4())
        self.received_at = time.time()
        self.deleted = False

    def is_visible(self):
     …

13 0 Open

Reliability & rate limiting medium

How to Mock a Circuit Breaker Reset Timeout in Python

This code implements a simple circuit breaker with a reset timeout test, simulating a flaky service to show half-open state transitions.

circuit-breaker reliability mock-testing

Python

import time
import random


class CircuitBreaker:
    def __init__(self, failure_threshold=3, reset_timeout=5):
        self.failure_threshold = failure_threshold
        self.reset_timeout = reset_timeout
        self.failure_count = 0
        self.last_failure_time = None
        self.state = "CLOSED"  # CLOSED (nor…

15 0 Open

Reliability & rate limiting easy

How to Mock a Timeout per HTTP Request in Python

Simulate a per-request HTTP timeout using unittest.mock to test timeout handling without network access.

mocking timeout testing

Python

import time
from unittest.mock import Mock, patch

# Simulate an HTTP client that might time out
def fetch_data(url, timeout=5):
    time.sleep(0.5)  # Simulate network delay
    return f"Response from {url}"

# Mock to test timeout behavior without real network
def test_timeout():
    mock_response = Mock(side_effect…

12 0 Open

Browse by section

Each section groups closely related Python snippets.