Re: [PATCH] attempt connects in parallel for IPv6-capable builds

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 29, 2016, 03:04 UTC
Message-ID: <xmqqtwlxjdbx.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20160128115720.GA1827@dcvr.yhbt.net>

Eric Wong <normalperson@yhbt.net> writes:

> getaddrinfo() may return multiple addresses, not all of which
> are equally performant.  In some cases, a user behind a non-IPv6
> capable network may get an IPv6 address which stalls connect().

I'd assume that you are not solving a hypothetical problem, but you may (at least sometimes) have to reach outside world from such a network environment. I further assume that git_tcp_connect() is not the only activity you do from such a network, and other network activities are similarly affected.

How do you work around the same issue for connections that do not go through git_tcp_connect()? The same issue would affect Git traffic going over git-remote-curl, and also your usual Web browser traffic, no?

What I am getting at is if it is saner to solve the issue like how curl(1) solves it with its -4/-6 command line options, e.g. by adding a pair of configuration variables "net.ipv[46] = true/false".