Next Call

April 15th 2021 @ 10am PST / 1pm EST

Meeting Recording Survey


Publishing - Yoav Weiss

ResourceTiming and NavigationTiming + Fetch



Beacon API

Possibility to get the HTTP status code from the Response Header ? · Issue #126 · w3c/navigation-timing 

Yoav: Feels like something we’d want to move to Resource Timing

Nic: I think there’s a similar issue there

Nicolás: You mentioned in the NavigationTiming issue that it would require some opt-in?

Yoav: I think that it won’t for NT, but would for RT

Nic: RT#90 is a duplicate on the RT side

Yoav: Makes sense to fold this one into the other one

AppCache meaning #140

Nic: Clarification question around what the time titled “AppCache”. What components can contribute to that time in the diagram. Yoav, you commented around it.

Yoav: AppCache is dead, let’s not bother with defining its delays too much. Benjamin - what about Firefox?

Benjamin: deprecated

Nic: In the case of NT, it’s not the AppCache feature, but we were referring to the browser cache in general. In the diagram we have AppCache before DNS connection. It was meant to cover the browser cache - how long it took to get the resource from disk cache. The name changed over time, but it’s not about the AppCache feature.

Yoav: As far as implementations go, either we fetch the resource from disk cache, or ignore the cache and go to the network. AFAIK, there are no scenarios where we wait on disk, and only then go to the network. I’m not sure that definition makes sense.

Nicolás: You’re saying that’s measuring when we try to see if it’s in disk cache and fail do we then go to the network? I also don’t understand what’s the delta between fetchStart and dnsStart.

Nic: We often see a non zero delta between those numbers and assumed it’s disks spinning up

Yoav: I’d assume we won’t go to disk unless we know we find something there

Nicolás: Worth investigating what’s happening there

Nic: In IE that time was accessing the cache index, which may not have been in memory

… I can see if today we still see a difference there

… The basic question was “what is that time?” We can try to inform that decision a little bit

Yoav: It would be interesting to do some research there.

Nic: Out of time, just wanted to point out great work on RT Fetch integration.