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Reliability & rate limiting

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

3 matches

How to Mock a Try Confirm Cancel Pattern in Python

Define a simple class with confirm and cancel methods, execute a try confirm with error handling, and print the final state.

try-except mock class

Python

class TCC:
    def __init__(self):
        self.confirmed = False
        self.cancelled = False

    def confirm(self):
        self.confirmed = True
        return "confirmed"

    def cancel(self):
        self.cancelled = True
        return "cancelled"

    def try_confirm(self):
        try:
            result =…

12 0 Open

Reliability & rate limiting easy

How to Retry on Specific Exception Tuples in Python

A decorator-based retry pattern that retries a function only when it raises exceptions specified in a tuple, with configurable retries and delay.

retry decorator exceptions

Python

import time
import random
from unittest.mock import patch


def retry_on_exceptions(retries=3, exceptions=(ValueError,), delay=0.1):
    def decorator(func):
        def wrapper(*args, **kwargs):
            for attempt in range(retries):
                try:
                    return func(*args, **kwargs)
          …

15 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

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