Async Retry Decorator

async_retry.py

import functools
import time
import random
import asyncio

def async_retry(max_retries=3, start_delay=2, backoff_factor=2, exceptions=(Exception,)):
    """Retry decorator for async functions with exponential backoff."""
    def decorator(func):
        @functools.wraps(func)
        async def wrapper(*args, **kwargs):
            delay = start_delay
            last_exception = None
            
            for attempt in range(1, max_retries + 1):
                try:
                    return await func(*args, **kwargs)
                except exceptions as e:
                    last_exception = e
                    
                    # Add jitter to delay to prevent thundering herd problem
                    jitter = random.uniform(0.8, 1.2)
                    sleep_time = delay * jitter
                    
                    print(f"Attempt {attempt} failed: {e}. Retrying in {sleep_time:.2f}s")
                    await asyncio.sleep(sleep_time)
                    
                    # Increase delay for next attempt
                    delay *= backoff_factor
            
            # If we get here, all retries failed
            raise last_exception
        return wrapper
    return decorator


# Usage
@async_retry(max_retries=5, exceptions=(aiohttp.ClientError, asyncio.TimeoutError))
async def fetch_url(session, url):
    async with session.get(url, timeout=30) as response:
        return await response.text()