1710587 - Show detailed reason for service worker request timings showing 0ms

Status: RESOLVED DUPLICATE of bug 1353798

(DevTools :: Netmonitor, enhancement, P3)

Description

[Yajo]

Attachment: screenshot-2021-05-11-10-45-01.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:88.0) Gecko/20100101 Firefox/88.0

Steps to reproduce:

Installed Firefox from flathub.org (not sure if relevant).

I'm inspecting network requests using developer tools as usual.

Actual results:

Under some circumstances, all network requests times appear as if they were 0ms.

Expected results:

Times should be properly measured.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'DevTools::Netmonitor' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Thank you for the report Yajo!

This indeed looks like a bug.

Any chance you could provide a test page we could use on our machines to see and debug the problem?

Comment 3

[Yajo]

I cannot reproduce it reliably (sometimes it works, sometimes not), but I can trigger the bug in https://googlechrome.github.io/samples/service-worker/basic/

Just scroll down and go to "Live Demo" section, and keep changing the icon and clicking on "Show Icon". Later, refresh the page and repeat.

I'm not sure that's the exact bug. It seems related to service workers. For some reason, some queries it's intercepting don't properly notice that they're actually querying the server.

If you can't reproduce it there, just tell me and I'll try to get other case.

Comment 4

[Hubert Boma Manilla (:bomsy)]

As these requests are fired from the service worker cache its expected that the duration/timings are closer to or zero ms

We are repurposing this instead make it clearer why it shows 0ms.
We could add more info to the tool tip of the duration column.

Comment 5

[viktor]

I also have this issue. This is in a case where the service worker does not have a cache, all request go through the network as normal, so it's not expected to take 0 ms. (The service worker is used only to show a custom page when the internet is down)
Is it a limitation of the timings that all service worker requests show 0 ms? In chrome this works as expected and it shows the actual network times, even though a service worker is involved.
This issue can be seen here: https://www.medino.com/product/aloe-pura-aloe-vera-gel-200ml

Comment 6

[viktor]

Attachment: Example illustrating the problem on https://www.medino.com/product/aloe-pura-aloe-vera-gel-200ml

Comment 7

[Hubert Boma Manilla (:bomsy)]

Same bug as Bug 1353798. Closing