Description
- uvloop version: 0.8.0
- python version: 3.6.0
- platform: Fedora 25
I was trying to create a HTTP service that connects to a mongo database to provide a CRUD API, that implemented some logic to reconnect to the mongo database if the connection was not available when the process started.
The problem I found is that the process stops listening on the HTTP TCP port after the first timeout of the connection to the mongo database. The problem does not happen when I use the default python event loop. I was trying to use the sanic library to implement the HTTP API, but the problem also happened when I switched to the aiohttp.web library, so this problem probably is not linked to a specific library code.
Here are the libraries versions that I used and the code that causes the problem:
- sanic version: 0.4.1
- motor version: 1.1
- pymongo version: 3.4.0
import asyncio
import uvloop
from sanic import Sanic
from sanic.response import json
from motor.motor_asyncio import AsyncIOMotorClient
from pymongo.errors import CollectionInvalid, ServerSelectionTimeoutError
DB_NAME = 'testdb'
COLLECTION_NAME = 'testcoll'
asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
loop = asyncio.get_event_loop()
conn = AsyncIOMotorClient(
host='127.0.0.1',
port=27017,
connectTimeoutMS=2000,
serverSelectionTimeoutMS=5000,
)
db = conn['testdb']
collection = db['testcoll']
app = Sanic()
async def start_db():
print('connecting to mongodb!')
try:
await db.create_collection(COLLECTION_NAME)
except CollectionInvalid:
pass
except ServerSelectionTimeoutError:
await asyncio.sleep(0.5)
print('trying to connect to mongodb again...')
loop.create_task(start_db())
return
# Indexes are supposed to be created here
print('connected to mongodb!')
@app.route('/')
async def handler(request):
data = await collection.find().to_list(None)
return json(data)
def main():
server = app.create_server(
host='127.0.0.1',
port=5000,
debug=True,
loop=loop,
)
loop.create_task(start_db())
asyncio.ensure_future(server, loop=loop)
# Start other asyncio things here
loop.run_forever()
if __name__ == '__main__':
main()EDIT: forgot to add the output log
output:
connecting to mongodb!
~/.local/lib/python3.6/site-packages/sanic/app.py:524: DeprecationWarning: Passing a loop will be deprecated in version 0.4.0 https://github.com/channelcat/sanic/pull/335 has more information.
DeprecationWarning)
2017-03-06 16:15:19,518: DEBUG:
sanic drawing here
2017-03-06 16:15:19,518: INFO: Goin' Fast @ http://127.0.0.1:5000
trying to connect to mongodb again...
/usr/lib64/python3.6/traceback.py:352: ResourceWarning: unclosed resource <TCPServer closed=False 0x7f7dcbf4b448>; object created at (most recent call last):
File "example_sanic.py", line 64, in <module>
main()
File "example_sanic.py", line 60, in main
loop.run_forever()
File "~/.local/lib/python3.6/site-packages/sanic/app.py", line 509, in create_server
return await serve(**server_settings)
filename, lineno, name, lookup_line=False, locals=f_locals))
connecting to mongodb!
trying to connect to mongodb again...