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Issue 668946 link

Starred by 3 users
Status: Archived
Owner: ----
Closed: Jan 2017
Cc:
igrigo...@chromium.org
mek@chromium.org
Components:
EstimatedDays: ----
NextAction: 2017-01-12
OS: All
Pri: 3
Type: Bug



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Resource Timing within the context of a service worker (workerStart in particular seems unhooked)

Project Member Reported by kenjibaheux@chromium.org, Nov 28 2016 
It appears that workerStart is never non-zero in a SW context.

Context: this came up while talking to a third party provider looking into using Foreign Fetch / Foreign Service Worker to enhance their offering. They want to track the latency impact of this approach and were surprised by not being able to capture a non zero workerStart for the initial request which should have resulted in creating a new worker.

Is workerStart properly hooked up within the SW context?
I assume that the spec already allows this information to be available within the SW context. But if it does not, the use case seems quite reasonable.

Comment 1 by kenjibaheux@chromium.org, Nov 28 2016 

The use case assumes that a SW gets to see Resource timing entries for the requests that are in its scope.

Example:
<link rel="style" href="https://example.com/this.css">

where this.css responds with a foreign service worker header (https://example.com/sw.js scope:/).

with sw.js, the developer expects being able to obtain information about the "this.css" request (i.e. workerStart, etc.), perhaps at some later point (e.g. subsequent request).

Comment 2 by kenjibaheux@chromium.org, Nov 28 2016

Components: Blink>ServiceWorker

Comment 3 by mek@chromium.org, Dec 9 2016

Cc: igrigo...@chromium.org
I'm not sure I'm the right person for this... Also I'm not sure what the spec currently does and doesn't specify with regards to service workers... I agree that it would be interesting for the service worker to be able to get performance metrics for requests it handles, rather than just for requests it makes, but I have no idea if that is spec'ed and/or implemented.

It doesn't even seem like resource timing for requests made by a service worker are correctly reported currently. Unless I'm misunderstanding what is supposed to work. For example I do get resource timing entries for fetches made by Cache.add(someUrl), but I don't get anything for the equivalent fetch(someUrl).

Comment 4 by igrigo...@google.com, Dec 14 2016 

Kenji: could we move this discussion to an RT issue on GitHub? [1]

The behavior you're describing above seems to make sense to me (on first pass, at least), and it's something we need to discuss and clarify in the spec.

[1] https://github.com/w3c/resource-timing/issues

Comment 5 by falken@chromium.org, Dec 16 2016

Cc: mek@chromium.org
Owner: kenjibaheux@chromium.org
Status: Assigned (was: Untriaged)
Over to Kenji for filing GitHub bug.

Comment 6 by kenjibaheux@chromium.org, Dec 16 2016

Labels: Needs-Feedback
NextAction: 2017-01-12
Filed one: https://github.com/w3c/resource-timing/issues/88

Comment 7 by shimazu@chromium.org, Jan 27 2017 

(bug triaging process) kindly ping for an expired NextAction bug:)

Comment 8 by kenjibaheux@chromium.org, Jan 27 2017

Owner: ----
Status: Archived (was: Assigned)
This needs to be resolved in spec land first.
The urgency on this has dropped (the original motivating factor was to allow a partner to assess the impact of foreign fetch).

Archiving, we can re-open a new bug if this becomes a priority again.
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