1858290 - Drop in default agent telemetry after Default Agent background task migration

Status: RESOLVED FIXED

(Toolkit :: Default Browser Agent, defect, P2)

Description

[Nick Rishel [:nrishel]]

There was a drop in telemetry after migrating the Default Agent to Firefox Background Tasks, seen in both Nightly and Beta builds.

Comment 1

[Nick Rishel [:nrishel]]

Attachment: Bug 1858290 - Prevent background task `setTimeout` overflow. r=nalexander

Comment 2

[Nick Rishel [:nrishel]]

Attachment: Bug 1858290 - Post: Detach pingsender process from Default Agent Background Task. r=nalexander

Depends on D190636

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/39145ab8550f
Prevent background task `setTimeout` overflow. r=nalexander,bytesized
https://hg.mozilla.org/integration/autoland/rev/db70bbc48ef5
Post: Detach pingsender process from Default Agent Background Task. r=nalexander

Comment 4

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/39145ab8550f
https://hg.mozilla.org/mozilla-central/rev/db70bbc48ef5

Comment 5

[Nick Rishel [:nrishel]]

We believe the issue remains as we're able to reproduce applications launched from the background task being closed with the background task. This could explain why our telemetry isn't sending, if pingsender closes with the background task then telemetry would race shutdown.

Comment 6

[Masatoshi Kimura [:emk]]

-backgroundtask switch will set LauncherFlags::eWaitForBrowser:
https://searchfox.org/mozilla-central/rev/7d77ff808f8407a3e4fc0911779da446c050f9ee/browser/app/winlauncher/LauncherProcessWin.cpp#153,161

if LauncherFlags::eWaitForBrowser is set, the launcher process will create a job object and assign the browser process to the job object. So when the background task exits, all processes in the job object will be killed:
https://searchfox.org/mozilla-central/rev/7d77ff808f8407a3e4fc0911779da446c050f9ee/browser/app/winlauncher/LauncherProcessWin.cpp#486-487

We will have to break away from the job when executing pingsender and the browser from Default Agent Notification.

Comment 7

[Masatoshi Kimura [:emk]]

That is, CREATE_BREAKAWAY_FROM_JOB flag is required here and here.

Comment 8

[Masatoshi Kimura [:emk]]

Please also fix this comment because we need JOB_OBJECT_LIMIT_BREAKAWAY_OK for a different reason.

Comment 9

[Masatoshi Kimura [:emk]]

Bug 1859445 will fix this.