From: Kuniyuki Iwashima > Sent: 17 November 2020 09:40 > > The SO_REUSEPORT option allows sockets to listen on the same port and to > accept connections evenly. However, there is a defect in the current > implementation. When a SYN packet is received, the connection is tied to a > listening socket. Accordingly, when the listener is closed, in-flight > requests during the three-way handshake and child sockets in the accept > queue are dropped even if other listeners could accept such connections. > > This situation can happen when various server management tools restart > server (such as nginx) processes. For instance, when we change nginx > configurations and restart it, it spins up new workers that respect the new > configuration and closes all listeners on the old workers, resulting in > in-flight ACK of 3WHS is responded by RST. Can't you do something to stop new connections being queued (like setting the 'backlog' to zero), then carry on doing accept()s for a guard time (or until the queue length is zero) before finally closing the listening socket. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
