Description
I'm working on a web-project and a few days ago I diagnosed a problem: after restarting the Redis service some urls were throwing a 500 error for multiple requests in a row though Redis was already running.
Version:
redis==4.5.4
Platform: What platform / version? (For example Python 3.5.1 on Windows 7 / Ubuntu 15.10 / Azure)
Python 3.10.10
Redis 7.0.5
Description:
`
import asyncio
import redis.asyncio as redis
aioredis_conn = redis.from_url(
url=f"redis://127.0.0.1:6379",
decode_responses=True
)
async def main():
while True:
print('*******')
try:
await aioredis_conn.get('something')
tasks = []
tasks.append(aioredis_conn.get('something'))
tasks.append(aioredis_conn.get('something'))
tasks.append(aioredis_conn.get('something'))
tasks.append(aioredis_conn.get('something'))
results = await asyncio.gather(*tasks, return_exceptions=True)
print(f'Gather results: {results}')
except Exception as e:
print(f'Caught general exception: {e}')
await asyncio.sleep(3)
asyncio.run(main())
`
What to do:
-
Start redis
-
Run script
-
Every 3 seconds you will see
Gather results: [None, None, None, None] -
Stop redis and wait for message in terminal
Caught general exception: Connection closed by server.
If you wait for more than 3 seconds, you will see also
Caught general exception: Error 61 connecting to 127.0.0.1:6379. 61.
-
Start redis and in terminal you will see
Gather results: [None, ConnectionError('Connection closed by server.'), ConnectionError('Connection closed by server.'), ConnectionError('Connection closed by server.')] -
On the next iteration of script the result is as expected:
Gather results: [None, None, None, None]
I don't expect to see exceptions in gather results, and also I'm very confused that these exceptions are from previous iteration.
Also I don't see this problem while using aioredis==2.0.1 and I assume that the root of the problem is in redis library.
Am I right and this is a bug. Or am I doing something wrong?