[asyncio] Client disconnects from server without pinging it.

[johnlage]

Some servers base sending PING messages on the last time the client sent data to the server, causing the client to thing that it has disconnected from not receiving data. Instead, the client should PING the server to check if it is still connected.

[shizmob]

RFC1459, section 4.6.2 seems to imply the PING message can only be sent by servers to clients, not vice-versa. Code to do something like this was actually in pydle a while ago, but I removed it because of this.

Could you point me to servers which base their PING messages off of this? I'd like to inspect their implementation.

[johnlage]

Actually, referencing that RFC it says "A PING message is sent at regular intervals if no other activity detected coming from a connection." I found this problem while connected to EsperNet, which uses charybdis, although they may have customized this particular thing.

[shizmob]

Just realised that it also states: "Servers should not respond to PING commands but rely on PINGs from the other end of the connection to indicate the connection is alive.", which makes this a valid implementation indeed. Definitely going to be putting back that code, then.

[johnlage]

Oh I just realized that the problem I was experiencing may not be solved by the fix you proposed, because the timeout was on pydle's side, not on the serverside (pydle closed the connection due to not recieving input.)