[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: Alright, I've backported the fix to 3.4. Closing this. -- stage: -> resolved status: open -> closed ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: > Jim ask for a backport. Sorry Jim, was replying from my email client, didn't see all messages. > This is arguably a security issue because it's a DoS vector. Yeah, I can see why. I can commit this to 3.4 in a week. Christian, feel free to commit this if

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: This is arguably a security issue because it's a DoS vector. I don't feel strongly about it though. -- ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Christian Heimes added the comment: Jim ask for a backport. In case the problem is not a security issue that needs to be backported, feel free to close the ticket. -- ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: Isn't 3.4 in security fixes only mode? -- status: pending -> open ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Christian Heimes added the comment: Yuri, are you going to backport the fix to 3.4? -- assignee: -> yselivanov nosy: +christian.heimes status: open -> pending versions: -Python 3.5 ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: Yes, that change addresses this issue. Thanks! Will this be backported? -- resolution: -> fixed ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: Cool, I will verify soon. -- ___ Python tracker ___ ___ Python-bugs-list

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: It looks like this was fixed by #27759!. Jim, could you please verify? -- ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Changes by Jim Fulton : -- type: behavior -> security ___ Python tracker ___ ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: > It also doesn't occur with uvloop, which I assume still uses sockets. No, uvloop doesn't use python sockets or select for IO at all. All IO is done in libuv. > WRT CPython/sockets this problem doesn't happen if I use asyncore to accept > connections and

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: WRT CPython/sockets this problem doesn't happen if I use asyncore to accept connections and hand them off to create_connection. :) It also doesn't occur with uvloop, which I assume still uses sockets. Also, FWIW, the relevant ZEO test passes if I use SSL, which

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Guido van Rossum added the comment: No, I just don't have a computer right now, only a phone. --Guido (mobile) -- ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: Running out of time to debug this today. I think this is a bug in CPython, in either socket or select module. When I inject some debug code in selectors.py and replace KQueue with select(), I can see that the server thread's selector stops working at some

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: Yuri, right you are. Thanks. Марк, see https://bugs.launchpad.net/zodb/+bug/135108/comments/9 -- ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Yury Selivanov added the comment: Jim, I think you wanted to post this link in this issue: https://bugs.launchpad.net/zodb/+bug/135108/comments/9 instead of in #27392. I can reproduce this on my mac, but so far I've no idea what's going on. -- ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: Here's a version sans prints -- Added file: http://bugs.python.org/file43581/echo-no-print.py ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Марк Коренберг added the comment: One more thing. Why you set socket.SO_LINGER ? and why lingering timeout is 0 seconds ? Removing that eliminate problem completely. -- ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Changes by Jim Fulton : Removed file: http://bugs.python.org/file43540/echo.py ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Марк Коренберг added the comment: Also I recommend you to use asyncio streams, instead of reinventing wheels. So, reading your command will look like: data = await stream.read_exactly(4) (len,) = unpack(">I", data) command = await stream.read_exactly(len) --

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Марк Коренберг added the comment: Plese reduce even more. I mean remove debugging, specifi commands, and all extra code, that is not related to original problem. -- ___ Python tracker

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Jim Fulton added the comment: This is already pretty minimal. There are no external dependencies. -- ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Guido van Rossum added the comment: Yeah, I'd like to see a more minimal repro to understand what's going in. -- ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

Марк Коренберг added the comment: Please reduce program, and make sure it still hangs. -- nosy: +mmarkk ___ Python tracker ___

[issue27386] Asyncio server hang when clients connect and immediately disconnect

New submission from Jim Fulton: I recently ported ZEO to asyncio. We'd had a bug in our old asyncore-based server where the server would hang if several connections were made and then immediately disconnected on Mac OS X. This was due to an error-handling bug in our code that we fixed. We