1005270 - Trigger experiments initialization on opening the addon manager UI

Status: VERIFIED FIXED

(Firefox Health Report Graveyard :: Client: Desktop, defect)

Description

[Georg Fritzsche [:gfritzsche]]

Currently we delay the experiment manager initialization for 30 seconds after "sessionstore-state-finalized" (unless we have active experiments) to avoid startup performance hits (bug 993084).
This means that you don't get to see the experiments category before those 30 seconds run out if you go straight to the addon manager UI.

Comment 1

[Georg Fritzsche [:gfritzsche]]

Note that this only applies when you:
* don't have active experiments running
* had experiments running in the past 180 days
* go to the addon manager earlier than 30-60 secs after "sessionstore-state-finalized"
... so i don't think this is too pressing.

Comment 2

[Georg Fritzsche [:gfritzsche]]

To fix this, i guess we can just trigger the experiment manager initialization from the addon manager UI, but that still means async initialization and cache load before the experiments category would show.

Comment 3

[Georg Fritzsche [:gfritzsche]]

Attachment: Fix experiments-changed notification & trigger init on AM UI load

* We now observe "EM-loaded" and from there trigger the experiments manager initialization when the addon manager UI is shown early.
* We didn't fire the experiments-changed notification on first cache load with no active experiment - fixed by always firing it on the first experiments evaluation.

https://tbpl.mozilla.org/?tree=Try&rev=c2a3f7baf7a7

Comment 4

[Georg Fritzsche [:gfritzsche]]

Attachment: Fix experiments-changed notification & trigger init on AM UI load

Try reminds me that i completely forgot to add the required test changes to the patch.

https://tbpl.mozilla.org/?tree=Try&rev=d98b5bb98bde

Comment 5

[Georg Fritzsche [:gfritzsche]]

https://hg.mozilla.org/integration/fx-team/rev/d2ff5ee7413d

Comment 6

[Georg Fritzsche [:gfritzsche]]

Comment on attachment 8422336 [details] [diff] [review]
Fix experiments-changed notification & trigger init on AM UI load

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Telemetry experiments.
User impact if declined: Experiments addon category not visible for some time after session start or if we loaded only inactive/historic experiments.
Testing completed (on m-c, etc.): Awaiting QA verification.
Risk to taking this patch (and alternatives if risky): Low.
String or IDL/UUID changes made by this patch: None.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/d2ff5ee7413d

Comment 8

[Sylvestre Ledru [:Sylvestre]]

I will wait for the QA verification before uplift to aurora.

Comment 9

[Andrei Vaida [:avaida]]

My understanding is that before this fix, the "Experiments" category was *not* being displayed in the Add-ons Manager earlier than 30-60 seconds after "sessionstore-state-finalized". 

As per Comment 1 and Comment 2, I assume that "sessionstore-state-finalized" should happen sometime after browser startup - please note that I did not find a log stating something similar to "sessionstore-state-finalized" in the experiments logs enabled via pref "experiments.logging.level;0".

My attempt of reproducing the problem in the first place on Nightly 32 2014-05-01 and Nightly 31 2014-04-19 (before the fix landed) was unsuccessful. Nightly 32 2014-05-01 successfully displayed the "Experiments" category from browser startup, while Nightly 31 2014-04-19 did not display the category *at all* after disabling the experiment. Nightly 32.0a1 (2014-05-22) [1] had the same behavior as the one from 2014-05-01, using a profile that currently has one disabled experiment, which was installed recently.

Georg, could you please let me know:
 * how and where can I see that "sessionstore-state-finalized"?
 * is there a better way to simulate the conditions from Comment 1?
 * anything else you think might help me verify this fix.

Comment 10

[Marco Mucci [:MarcoM]]

(In reply to Andrei Vaida, QA [:avaida] from comment #9)
> My understanding is that before this fix, the "Experiments" category was
> *not* being displayed in the Add-ons Manager earlier than 30-60 seconds
> after "sessionstore-state-finalized". 
> 
> As per Comment 1 and Comment 2, I assume that "sessionstore-state-finalized"
> should happen sometime after browser startup - please note that I did not
> find a log stating something similar to "sessionstore-state-finalized" in
> the experiments logs enabled via pref "experiments.logging.level;0".
> 
> My attempt of reproducing the problem in the first place on Nightly 32
> 2014-05-01 and Nightly 31 2014-04-19 (before the fix landed) was
> unsuccessful. Nightly 32 2014-05-01 successfully displayed the "Experiments"
> category from browser startup, while Nightly 31 2014-04-19 did not display
> the category *at all* after disabling the experiment. Nightly 32.0a1
> (2014-05-22) [1] had the same behavior as the one from 2014-05-01, using a
> profile that currently has one disabled experiment, which was installed
> recently.
> 
> Georg, could you please let me know:
>  * how and where can I see that "sessionstore-state-finalized"?
>  * is there a better way to simulate the conditions from Comment 1?
>  * anything else you think might help me verify this fix.

Hi Andrei, Georg is on PTO.  Adding a note for Benjamin to see if he can answer your questions.

Comment 11

[Benjamin Smedberg]

Don't worry about sessionstore-state-finalized, just talk in terms of browser startup.

The conditions in comment 1 were fairly easy to repro for me. After an experiment is disabled or finished, if you start the browser and immediately loaded about:addons the experiment category was not present.

Comment 12

[Andrei Vaida [:avaida]]

(In reply to Benjamin Smedberg  [:bsmedberg] from comment #11)
> Don't worry about sessionstore-state-finalized, just talk in terms of
> browser startup.
> 
> The conditions in comment 1 were fairly easy to repro for me. After an
> experiment is disabled or finished, if you start the browser and immediately
> loaded about:addons the experiment category was not present.

Thank you for clarifying this, Benjamin. I can confirm that this issue is verified fixed on Nightly 32.0a1 (2014-05-25) [1].

[1] Mozilla/5.0 (Windows NT 6.1; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0

Comment 13

[Sylvestre Ledru [:Sylvestre]]

Comment on attachment 8422336 [details] [diff] [review]
Fix experiments-changed notification & trigger init on AM UI load

Thanks. Approving then.

Comment 14

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/2c7882800cdd

Comment 15

[Kamil Jozwiak [:kjozwiak]]

Reproduced the original issue using the following build:
- http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014-05-25-00-40-02-mozilla-aurora/

- Removed the experiment via about:addons (ensured that it was removed) and than closed FX
- Re-loaded FX and opened about:addons and the "Experiments" container wasn't visible

Once the original problem was reproduced, used the following build for verification:
- http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2014-05-29-00-40-03-mozilla-aurora/

- Removed the experiment from the "Experiments" container under about:addons
- Closed/Opened FX and quickly loaded about:addons, ensured that the "Experiments" container is visible and the removed experiment is present
- Removed multiple experiments and ensured that the "Experiments" container quickly appeared once FX was launched