Re: Proposal to measure end-user latency

I'd imagine that you'd want to re-use the same timing information that is
collectable within the javascript, and likely in the same format (that just
makes sense from an engineering perspective).
That format and when each of the timestamps is collected is currently
defined in the W3C.

I'd just ask them to trigger the collection of that data collection upon
the condition stated in the header.
The interaction with HTTP would just be to add that header to the IANA
registry, if so... doesn't seem very likely to require this WG.

-=R


On Tue, Sep 3, 2013 at 1:56 PM, Willy Tarreau <w@1wt.eu> wrote:

> Hi Roberto,
>
> On Tue, Sep 03, 2013 at 01:49:22PM -0700, Roberto Peon wrote:
> > I've also wanted this-- this would allow servers to perform automatic
> > testing/analysis without requiring content writers to add code. This is
> > desirable for doing things like changing the order/frequency of server
> > push, etc.
> > This would be something in addition to what is available at the
> application
> > layer.
> > In particular, a server could add a header indicating that it would like
> to
> > see the WebTiming results for the page POSTed to a particular URI after
> > some condition (e.g. X seconds, X resource loaded, etc) had been met.
> >
> > Despite the fact that I believe this is truly useful, I believe also that
> > this is probably not the right place to standardize such a thing-- I
> > believe the W3C is.
>
> It depends if it's done at the protocol level or higher in fact. For
> example
> TCP uses timestamps for exactly the same reason and they're conveyed inside
> the protocol itself. I think it could be the W3C as you suggest if we find
> that it's too application-oriented to be related in any way with the
> protocol.
> Eg. if the protocol as no reason to know about this of course I'd agree.
> But
> if the protocol leaves a room for a timestamp or whatever, then it makes
> sense
> to have it here. The role of intermediaries would also have to be
> discussed.
>
> Best regards,
> Willy
>
>