Reference library

Reliability & rate limiting

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

4 matches

Fixed Window Counter Rate Limiting in Python

A simple fixed window counter rate limiter that allows a maximum number of requests per 60-second window, with a mock time simulation.

rate-limiting fixed-window time

Python

from collections import deque
from time import time

class FixedWindowCounter:
    def __init__(self, max_requests):
        self.max_requests = max_requests
        self.window_start = int(time())
        self.window_count = 0

    def allow_request(self):
        current_time = int(time())
        if current_time >=…

13 0 Open

Reliability & rate limiting easy

How to Implement a Dead Letter Queue Replay in Python

A mock Dead Letter Queue that stores failed messages with retry attempts and replays them with a simple retry counter.

dead-letter-queue queue retry

Python

import json
from collections import deque

class DeadLetterQueue:
    def __init__(self):
        self.messages = deque()
    
    def add_message(self, message_id, payload, attempts=3):
        """Add a message to the DLQ with retry metadata."""
        self.messages.append({
            "id": message_id,
           …

13 0 Open

Reliability & rate limiting easy

How to Implement a Sliding Window Counter in Python

This code implements an approximate sliding window counter using a deque of time-based buckets to track event counts within a recent time window.

sliding-window rate-limiting deque

Python

from collections import deque
from time import time


class SlidingWindowCounter:
    def __init__(self, window_size, bucket_size=1):
        self.window_size = window_size
        self.bucket_size = bucket_size
        self.buckets = deque()

    def _evict_expired(self, now):
        while self.buckets and self.buck…

13 0 Open

Reliability & rate limiting easy

How to Mock Daily and Monthly Quota Counters in Python

Track daily and monthly API call usage with automatic resets, quota checks, and limits using a Python class.

quota rate-limiting class

Python

import random
from datetime import datetime, timedelta


class QuotaCounter:
    def __init__(self, daily_limit=1000, monthly_limit=20000):
        self.daily_limit = daily_limit
        self.monthly_limit = monthly_limit
        self.daily_usage = 0
        self.monthly_usage = 0
        self.current_day = datetime.n…

17 0 Open

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