No, nginx should not have this problem as it uses fd passing to gracefully handoff connections.
HAProxy only has this issue on Linux because Linux's SO_REUSEPORT implementation unfortunately introduces a race condition between accept and close. While I haven't personally tested it, HAProxy on one of the BSDs should not have this small window of downtime.
HAProxy only has this issue on Linux because Linux's SO_REUSEPORT implementation unfortunately introduces a race condition between accept and close. While I haven't personally tested it, HAProxy on one of the BSDs should not have this small window of downtime.