From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pb-smtp21.pobox.com (pb-smtp21.pobox.com [173.228.157.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 91BED12AAFD for ; Sat, 6 Jul 2024 17:18:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.228.157.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720286306; cv=none; b=qDPkCUEiMf1D9eLRDkClGDXVOO0W09STerwNyNquWmzVrwWVljc4uBk0nL1uxOKmuYY41nQ9ZgwAjqofS1pIsnwrkiJFHiACqK9sxz3MWd4vMhtBJImN2qpUDh5R0TjvExCblj8co2lVo7t49Y5F5zmcooF28HVjrMqJUFLBP6U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720286306; c=relaxed/simple; bh=wUXPA+V37pPCahqhgnq/H9VszezFokn77s+FTjZqtJE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=XxERDQVJnl6yJbs0xdx4WhQo22RMX4DwWcERcMs0HZkY8uZsFbYHzgJBpo1riLfHNcGJk7bN0NATc/pM8HSyYmotTxYAm0cX2nsW8xC0lv1x0BVeWqoV22onYVTA6elQDB+etTeR332zHkN4CQGOfyF8rXuCzf6Vq4j/Bw8fD0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com; spf=pass smtp.mailfrom=pobox.com; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b=gHq9E9wo; arc=none smtp.client-ip=173.228.157.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pobox.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b="gHq9E9wo" Received: from pb-smtp21.pobox.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 0AA6A2ACA5; Sat, 6 Jul 2024 13:18:18 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:in-reply-to:references:date:message-id:mime-version :content-type; s=sasl; bh=wUXPA+V37pPCahqhgnq/H9VszezFokn77s+FTj ZqtJE=; b=gHq9E9wofek/DXZmuxJOhDNoOjwzV/2m9x0LQZNymqjO6RR7c8YVuG 3o7QsPryND5NlK5R63AVEEbt3tonNDwksLrV5yHgtXQ4gxyc55+NhFuZQp3E8lLP yLJ6gtE9qP//Md2aTMqe7Lc1L+n8LMI67/90okwZttXZt+DebR40I= Received: from pb-smtp21.sea.icgroup.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 023C32ACA4; Sat, 6 Jul 2024 13:18:18 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.125.219.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp21.pobox.com (Postfix) with ESMTPSA id 837AB2ACA3; Sat, 6 Jul 2024 13:18:14 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: Jeff King Cc: "brian m. carlson" , git@vger.kernel.org, Johannes Schindelin , Eric Sunshine , Derrick Stolee Subject: Re: [PATCH v3 0/4] Additional FAQ entries In-Reply-To: <20240706064758.GG700645@coredump.intra.peff.net> (Jeff King's message of "Sat, 6 Jul 2024 02:47:58 -0400") References: <20240704003818.750223-1-sandals@crustytoothpaste.net> <20240706064758.GG700645@coredump.intra.peff.net> Date: Sat, 06 Jul 2024 10:18:12 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Pobox-Relay-ID: BA7EAD9A-3BBB-11EF-906C-DFF1FEA446E2-77302942!pb-smtp21.pobox.com Jeff King writes: > On Thu, Jul 04, 2024 at 09:23:28PM +0000, brian m. carlson wrote: > >> > Buffering the entire thing will break because ...? Deadlock? Or is >> > there anything more subtle going on? >> >> When we use the smart HTTP protocol, the server sends keep-alive and >> status messages as one of the data streams, which is important because >> (a) the user is usually impatient and wants to know what's going on and >> (b) it may take a long time to pack the data, especially for large >> repositories, and sending no data may result in the connection being >> dropped or the client being served a 500 by an intermediate layer. We >> know this does happen and I've seen reports of it. > > Additionally, I think for non-HTTP transports (think proxying ssh > through socat or similar), buffering the v0 protocol is likely a total > disaster. The fetch protocol assumes both sides spewing at each other in > real time. Yeah, beyond one "window" that a series of "have"s are allowed to be in flight, no further "have"s are sent before seeing an "ack/nack" response, so if you buffer too much, they can deadlock fairly easily. > ... So I'm OK > with just telling people "make sure your proxies aren't buffering" as a > general rule, rather than trying to get into the nitty gritty of what is > going to break and how. Sounds fair. Thanks.