I don't think it's a bug in Go's http stack. The TCP FIN from the client just says "I've closed my write end of the connection". In this case the client actuall

I don't think it's a bug in Go's http stack. The TCP FIN from the client just says "I've closed my write end of the connection". In this case the client actually did a full close of the socket, i.e. it's actually closed for both reading and writing - but TCP doesn't communicate that fact. And HTTP says that in this situation (the other end closed its write half of the connection), you should still send the response back and then close your end of the connection. The server can't know[1] that client has fully closed the connection until it tries to write something to it - I'm guessing there is some sort of long polling going on here, so the server has parked the http request somewhere and isn't going to write anything to the connection until something happens (if ever). After all, at this point the server doesn't know the TCP connection is fully closed, it thinks it's half closed. [1] Unless you also enable tcp keepalive, the keepalive would discover that the socket is closed on the other end (after a couple of hours by default).