Reference library

Reliability & rate limiting

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

6 matches

Chaos Inject Random Failures in Python

Simulate random failures in a Python function to test error handling and resilience, using random thresholds and controllable success rates.

chaos-engineering random resilience

Python

import random


def unreliable_function(success_rate: float = 0.7) -> str:
    """Simulate a function that sometimes fails."""
    if random.random() > success_rate:
        raise ConnectionError("Simulated network failure")
    return "Operation completed successfully"


if __name__ == "__main__":
    random.seed(42)…

15 0 Open

Reliability & rate limiting easy

How to Inject Random Latency for Chaos Testing in Python

Mock unreliable services by wrapping functions with a decorator that adds random network-like delays before execution.

chaos-engineering decorators latency

Python

import random
import time
from functools import wraps

def inject_latency(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        latency = random.uniform(0.1, 0.5)
        print(f"Injecting {latency:.3f}s latency...")
        time.sleep(latency)
        return func(*args, **kwargs)
    return wrapper

@inje…

12 0 Open

Reliability & rate limiting easy

How to Mock Fault Injection Percentage in Python

Simulate a service with a 30% failure rate using random.random to test error handling and retries.

fault-injection random testing

Python

import random

class Service:
    def call(self):
        if random.random() < 0.3:  # 30% failure rate
            raise ConnectionError("Simulated network fault")
        return "ok"

def main():
    svc = Service()
    random.seed(42)  # deterministic for demonstration
    results = []
    for _ in range(10):
     …

14 0 Open

Reliability & rate limiting easy

How to Mock a Slow Startup Probe in Python

Simulate slow service initialization with a configurable mock delay to test readiness probes.

startup probe mock reliability

Python

import time
from dataclasses import dataclass, field


@dataclass
class StartupProbe:
    name: str
    min_wait_sec: float = 0.5
    max_wait_sec: float = 2.0
    _ready: bool = field(default=False, init=False, repr=False)

    def initialize(self) -> None:
        """Simulate slow startup with a fixed mock delay."""…

13 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…

13 0 Open

Reliability & rate limiting easy

How to mock a fallback return value in Python

Test a function that returns a default value on failure by mocking requests.get and its side effects.

unittest mocking requests

Python

from unittest.mock import Mock, patch
import requests

def fetch_data(url, default=None):
    try:
        response = requests.get(url)
        response.raise_for_status()
        return response.json()
    except (requests.RequestException, ValueError):
        return default

with patch("requests.get") as mock_get:
…

15 0 Open

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