What is the best way to retry async API calls using aiohttp? I want to retry the request for the standard socket error, timeout error, etc as well as for certain status codes 500, 501. I have tried using aiohttp_async, but can't get it to work:

import asyncio
from aiohttp import ClientSession
from aiohttp_retry import RetryClient

# Async single retry fetch
async def async_retry_fetch(url, retry_client):
    async with retry_client.get(url, retry_attempts=3, retry_for_status=[500, 501]) as response:
        try:
            data = await response.json()
        except Exception as e:
            raise Exception("Could not convert json")
    return data

async def main():
    urls = [
        "https://httpstat.us/200",
        "https://httpstat.us/500"
    ]
    api_calls = []
    async with ClientSession() as session:
        retry_client = RetryClient(session)
        for url in urls:
            api_calls.append(async_retry_fetch(url, retry_client))
    res = await asyncio.gather(*api_calls, return_exceptions=True)
    print("RESULT", res)

asyncio.run(main())

Output:

RESULT [AttributeError("'ClientSession' object has no attribute 'debug'"), AttributeError("'ClientSession' object has no attribute 'debug'")]

CodePudding user response：

It looks like you have installed aiohttp_retry version 2.x
but you use arguments for version 1.2 and this gives AttributeError.

Old version could use

get(..., retry_attempts=3)

but new version needs

get(..., retry_options=ExponentialRetry(attempts=3)

or

RetryClient(..., retry_options=ExponentialRetry(attempts=3))

But attempts has default value 3 so you could skip it.

Other problem is that RetryClient() can't get session as parameter.
And it doesn't need it because it creates own ClientSession() in __init__

See source code

This works for me:

import asyncio
from aiohttp_retry import RetryClient, ExponentialRetry

class MyLogger():
    def debug(self, *args, **kwargs):
        print('[debug]:', *args, **kwargs)
    
async def async_retry_fetch(url, retry_client):

    retry_options = ExponentialRetry(attempts=3)

    #async with retry_client.get(url) as response:
    # OR
    async with retry_client.get(url, retry_options=ExponentialRetry(attempts=3), raise_for_status=[500, 501]) as response:
        try:
            data = await response.json()
        except Exception as e:
            raise Exception("Could not convert json")

    return data

async def main():
    urls = [
        "https://httpstat.us/200",
        "https://httpstat.us/500",
        "https://httpstat.us/501",
        "https://httpbin.org/status/500",
        "https://httpbin.org/status/501",
        "https://httpbin.org/json"
    ]

    #async with RetryClient(logger=MyLogger(), retry_options=ExponentialRetry(attempts=3), raise_for_status=[500, 501]) as retry_client:
    # OR
    async with RetryClient(logger=MyLogger()) as retry_client:
        api_calls = []
        
        for url in urls:
            api_calls.append(async_retry_fetch(url, retry_client))
            
        res = await asyncio.gather(*api_calls, return_exceptions=True)
 
        for item in res:
            print(item)
            print('---')

# --- start ---

asyncio.run(main())

Result:

[debug]: Attempt 0 out of 3
[debug]: Attempt 0 out of 3
[debug]: Attempt 0 out of 3
[debug]: Attempt 0 out of 3
[debug]: Attempt 0 out of 3
[debug]: Attempt 0 out of 3
[debug]: Attempt 1 out of 3
[debug]: Attempt 1 out of 3
[debug]: Attempt 1 out of 3
[debug]: Attempt 1 out of 3
[debug]: Attempt 2 out of 3
[debug]: Attempt 2 out of 3
[debug]: Attempt 2 out of 3
[debug]: Attempt 2 out of 3
Could not convert json
---
500, message='Internal Server Error', url=URL('https://httpstat.us/500')
---
501, message='Not Implemented', url=URL('https://httpstat.us/501')
---
500, message='INTERNAL SERVER ERROR', url=URL('https://httpbin.org/status/500')
---
501, message='NOT IMPLEMENTED', url=URL('https://httpbin.org/status/501')
---
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