Re: [Beast] Slow HTTP connect on Windows. Normal?

From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2020-12-14 18:42:34

On 14/12/2020 18:27, Dominique Devienne via Boost-users wrote:

> I finally figured this out, mostly by chance...
> 
> As the extract below shows, Beast's example uses
> tcp::endpoint{net::ip::make_address("0.0.0.0"), port}
> in its sample usage, and I had copy/pasted that in my code (using
> "0.0.0.0"). This works, in that the server
> starts fine, and clients work fine too, but leads to those > 1,000ms
> client connection times on Windows.

Now you describe this, this is familiar. Windows has always done this.
Sorry I didn't think of it sooner.

> While using e.g. tcp::endpoint{ tcp::v6(), port } results in 20-30ms
> connection times on Windows. (2-3ms on Linux).

If you're on loopback and you'd like to close that gap, you need to turn
on SIO_LOOPBACK_FASTPATH. I've no idea if ASIO can do that for you, I'm
still on a pre-churn ASIO. An alternative is to bind to a real NIC, and
not go via loopback.

If you're on a real NIC over a real network, I find a 20-30ms connection
time abnormal. Windows 10 has a fast TCP stack, compared to previous
Windows. It should be single digit milliseconds.

Niall