W3C

Web Performance

25 Feb 2015

Attendees

Present
plh, igrigorik, Yoav, Michael, Tobin, Todd
Regrets
Chair
plh?
Scribe
plh

Contents


NEL PRs

https://github.com/w3c/navigation-error-logging/pull/30

igrigorik: included the 500 requests yesterday
... 4xx won't be part of it
... only 3xx

yoav: is there a mechanism for site owners to know about 404 errors?
... even they're content errors

igrigorik: 500 are already logged
... 404 can already be extracted
... shooting for the minimal here: just protocol errors

yoav: so 5xx is for gateways that may have lost the requet along the way

igrigorik: yes
... content errors and application errors shoulnd't be included imo

yoav: makes sense
... could be worthwhile to know that logic in the spec btw
... adding a note on why 4xx aren't there

Todd: still little ensure on 5xx
... might make it optional
... it's a little on a the boundary

igrigorik: in our current implementation, we report them. it's convenient for folks that are using it and in fact, they'd prefer more data but I'm pushing back

todd: I'm imagining the case where they wouldn't want to see the 500

igrigorik: [examples like CDNs]
... to start, we could make it optional and see the experience

yoav: opt-in by apps or by implementation?

igrigorik: "user agent MAY report 5xx" and tweaks with experience
... I'll update the proposal to make it optional and add a note on 4xx

https://github.com/w3c/navigation-error-logging/pull/29

igrigorik: unregister report uris
... seveal report uris for reliability purposes
... we'd like to provide a way to remove them
... if the report uri returns a 410, that's a signal it needs to be removed
... second case is for the user agent to GC the report URIs if it wants to
... (such as multiple failures)

todd: does 410 need an age so that the report URI can unblock itself?

igrigorik: not sure
... there is also retry after with the max-age
... you could respond that
... not sure if we need it in the spec

todd: don't think it's important to have in the first iteration but could imagine scenarios for it

igrigorik: I'll open a new bug and iterate there
... can I merge the pull requests?

plh: sure

[others are ok]

igrigorik: can we rename the repo to network-error-logging

plh: can we publish the FPWD for NEL?

[no objection heard]

Resolved: NEL to FPWD

Performance timeline PR7 and related

igrigorik: looking at service worker and sync'ing our API with it
... editorial exercise
... moved the Performance interface into PT
... so a bit of clean-up
... also in UT and RT to remove references to window
... since it's also available on worker

plh: did you move Timing-Allow-Origin as well?

igrigorik: not yet but agree to move

plh: I'll do the merge by tomorrow

HRT issue 1

https://github.com/w3c/hr-time/issues/1#issuecomment-75820353

igrigorik: related to service worker as well
... making the timeline start consistent
... ie all start if the start of the worker (dedicated or shared)

michael: for shared workers, you couldn't sync up a start time
... for dedicated, we were able to be more direct

igrigorik: a worker could start an other worker

michael: as long as they share the start time of the document, it's ok

igrigorik: it seems odd to distinguish

plh: do we have implementation of hrt for worker?

igrigorik: not sure

yoav: would be valuable to have both

igrigorik shared worker doesn't have a document

scribe: could also be a push
... completely detached

igrigorik: the app can communicate the start time of the document (as well as performance.now)
... as a follow up, would be interested to see if it's implemented

todd: I don't think IE does support on worker

http://w3c.github.io/hr-time/#sec-time-origin

[...]

yoav: looks like there is code in chrome for that
... not sure if it's shipped

plh: follow on the issue thread

add workerStart to measure ServiceWorker startup

https://lists.w3.org/Archives/Public/public-web-perf/2015Feb/0066.html

igrigorik: new attribute on both NT and RT
... the point at which we route the request to the service worker
... if no SW, it returns 0

plh: can you establish the SW time with one attribute?

http://w3c.github.io/navigation-timing/#h-processing-model

igrigorik: that would be the difference between workerStart and startTime

plh: workerStart is between startTime and linkNegotiationStart?

igrigorik: correct
... I'll create a pull for it

plh: and I'll update the graphic

todd: if you do a fetch and the SW does complex network operations, how do we report that?

igrigorik: not sure how to communicate that
... you would see alll of those in the SW
... but would be opaque to the page
... you would have to move your logic in the service woker

plh: if multiple request, what would you see?

igrigorik: almost like it came from the cache

next steps for "PerformanceObserver"

interface LazyPerformanceEntryList {
   bool HasEntryType(string);
   PerformanceEntryList getEntries();
   PerformanceEntryList getEntriesByType(DOMString entryType);
}

getEntriesByName(DOMString entryName)?

Todd: this looks good to us
... one question: current proposal interplays with performance timeline
... should we hook it earlier? ie performance timeline isn't required

igrigorik: if you want all events, you register your PO right away

yoav: can we unite the concepts and add navigation request as well?

igrigorik: would be odd to have past timing information
... for nav timing, maight be ok, but would be odd for frame timing

todd: can you opt-in? on document load, nav timing and RT are all loaded for you
... with PO, i may want to use that for them
... it feels strange to come up with a new construct and not be able to do the things we did before

igrigorik: there is overlap

[...]

scribe: NT and RT are in a special place

plh: for NT< you'll get it in the observer after the load event

igrigorik: ok. next step is to do a pull request

[End of minutes]

Minutes formatted by David Booth's scribe.perl version 1.138 (CVS log)
$Date: 2015/03/10 20:30:08 $