Server say "Unhandled exception CancelledError" after send date

[tonal]

Long story short

Error in log after send date

Traceback (most recent call last):
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/web_protocol.py", line 435, in start
    yield from resp.write_eof()
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/web_response.py", line 583, in write_eof
    yield from super().write_eof(body)
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/web_response.py", line 420, in write_eof
    yield from self._payload_writer.write_eof(data)
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/http_writer.py", line 282, in write_eof
    yield from self.drain(True)
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/http_writer.py", line 295, in drain
    yield from self._stream.drain()
  File "/opt/img_lib/venv/lib/python3.6/site-packages/aiohttp/http_writer.py", line 128, in drain
    yield from self._protocol._drain_helper()
  File "/opt/pyenv/versions/3.6.1/lib/python3.6/asyncio/streams.py", line 211, in _drain_helper
    yield from waiter
concurrent.futures._base.CancelledError

Expected behaviour

I do not wait CancelledError here

Actual behaviour

My server processes 10 - 30 requests per second.
The error appears every 5 to 10 minutes.

Steps to reproduce

I do not known how to reproduce

Your environment

aiohttp 2.2.3
python 3.6.1
ubuntu 12.04 & 14.04

[asvetlov]

You don't expect web handler cancellation but the handler is cancelled if connection to client is lost (or closed by peer, it doesn't matter).
Quite not clean to me: are you talking about incorrect behavior or just annoying log message?

[fafhrd91]

I think this is web_protocol problem. we need to catch CancelledError for write_eof()

[asvetlov]

+1

[tonal]

I have not noticed any incorrect behavior so far.
Only errors in the log

[asvetlov]

Got it

[fafhrd91]

fixed in master

[lock]

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