Investigate occasional JSONDecodeError in integration tests

[vdusek]

• Our integration tests occasionally fail with a JSONDecodeError.
• The issue occurs on both Python 3.10 and 3.13.
• It affects probably all integration tests.
• Example of such runs:
  • https://github.com/apify/apify-sdk-python/actions/runs/19227048761/attempts/1
  • https://github.com/apify/apify-sdk-python/actions/runs/19227048761/attempts/2
  • https://github.com/apify/apify-sdk-python/actions/runs/19166267956/attempts/1
  • https://github.com/apify/apify-sdk-python/actions/runs/19060438705/attempts/1
• The failures suggest that the platform occasionally returns an unexpected or malformed response.

[Pijukatel]

The issue can be reproduced by bombing API. Start some long running actor run and run for example code like this:

from apify_client import ApifyClientAsync
import asyncio

async def main():
    client = ApifyClientAsync(token="...")
    run_client= client.run(run_id='ACTOR__RUN_ID')
    tasks  = []
    for i in range(1000):
        tasks.append(asyncio.create_task(run_client.wait_for_finish()))

    await asyncio.gather(*tasks)

if __name__ == '__main__':
    asyncio.run(main())

Initially it just keeps polling for the actor run. After a while the rate limiter kicks in and there is 429 response with API rate limit error, but after that the API starts returning 200 response with empty bytes, which causes the error in the Python client.

[raethlo]

Note: @danpoletaev is investigating, so far we were unable to repro, we're looking if this could be a python client issue.

[Pijukatel]

Possibly an Impit issue. In touch with @barjin