udp reuseport when reload/restart

[Sergey Kandaurov]

> On 22 Sep 2020, at 05:34, Gao,Yan(ACG VCP) <gaoyan09 at baidu.com> wrote:
> 
> How to handle udp/quic logical connection with reuseport when reload/restart. For tcp, old worker can only handle old established connection, and do not accept new connection ever.

The current behaviour is to reject new QUIC connections
with CONNECTION_REFUSED after graceful shutdown was initiated,
and let already established connections to complete.

-- 
Sergey Kandaurov