- From: Maciej Stachowiak <mjs@apple.com>
- Date: Mon, 18 Feb 2008 18:46:31 -0800
- To: Mark Baker <distobj@acm.org>
- Cc: Kris Zyp <kzyp@sitepen.com>, public-webapi@w3.org
On Feb 15, 2008, at 2:09 PM, Mark Baker wrote: > > On 2/14/08, Kris Zyp <kzyp@sitepen.com> wrote: >>> >> Another functionality that I believe would be extremely valuable to >> expose >> for XHR would be HTTP pipelining control. Most browsers do not >> provide HTTP >> pipelining because of compatibility concerns and performance >> implications of >> improperly order requests. > > I thought it was just that most proxies don't support it on the > outbound connection. And I've never seen any ordering problems from > the support, or lack thereof, of pipelining. > > But I certainly agree that pipelining control would be really useful. Last time I looked into this, there were some proxies and some origin server configurations (in particular certain Apache modules, perhaps now obsolete) that broke with pipelining. Since it is not possible to find out from the server if pipelining is correctly supported, and since it is not generally possible to tell from the response that it has failed, enabling it by default in the browser http stack was not a safe thing to do. Since the breakage is caused in at least some cases by proxies, it is not in general safe to let XHR users opt in since they may control the origin server but generally would not control whatever proxies are between the server and the user. Pipelining is a great potential performance improvement and it's sad that it can't safely be used on the public Internet right now, so I hope we someday find a way out of the impasse. Regards, Maciej
Received on Tuesday, 19 February 2008 02:46:44 UTC