1622263 - Add Telemetry for the about:home caching mechanism

Status: VERIFIED FIXED

(Firefox :: New Tab Page, task, P3)

Description

[Mike Conley (:mconley) (:⚙️)]

In a session, we should try to get a measure of:

1. Whether the cache was:
   • Non-existent
   • Valid and loaded
   • Corrupt and discarded
   • Late and ignored
2. Time spent constructing the cached document in the child
3. How long it takes to paint about:home at startup when the cache is enabled and valid

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1622263 - Add Telemetry for about:home startup cache. r?Gijs!,data-review=mmccorquodale

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1622263 - Add tests for scenarios when the about:home startup cache isn't used. r?Gijs!

This doesn't include tests for the CACHE_RESULT_SCALARS.CORRUPT and
CACHE_RESULT_SCALARS.LATE cases. Those tests will be added in
bug 1633051.

Depends on D81189

Comment 3

[Mike Conley (:mconley) (:⚙️)]

Attachment: Data review request.md

Comment 4

[Megan McCorquodale]

Comment on attachment 9159473 [details]
Data review request.md

1.    Is there or will there be documentation that describes the schema for the ultimate data set in a public, complete, and accurate way? 
Yes, this will be documented in the probe dictionary. 

2.    Is there a control mechanism that allows the user to turn the data collection on and off?
Yes, by opting out of telemetry. 

3.    If the request is for permanent data collection, is there someone who will monitor the data over time?
Not permanent data collection. 

4.    Using the category system of data types on the Mozilla wiki, what collection type of data do the requested measurements fall under?
Category 1, Technical data.

5.    Is the data collection request for default-on or default-off?
Default on. 

6.    Does the instrumentation include the addition of any new identifiers?
No new identifiers.

7.    Is the data collection covered by the existing Firefox privacy notice? 
Yes.

8.    Does there need to be a check-in in the future to determine whether to renew the data? 
Yes, check in in 6 months. 

9.    Does the data collection use a third-party collection tool? 
No. 

----
data-review +

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e8290c6bfdaa
Add Telemetry for about:home startup cache. r=Gijs,data-review=mmccorquodale
https://hg.mozilla.org/integration/autoland/rev/ebcad04b8151
Add tests for scenarios when the about:home startup cache isn't used. r=Gijs

Comment 6

[Narcis Beleuzu [:NarcisB]]

Backed out for bc failures on browser_locale_change.js

Backout link: https://hg.mozilla.org/integration/autoland/rev/b48777a21aabc35311956a1a1395a5dbba8c1a77
Log link: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=308402877&repo=autoland&lineNumber=26175

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/10963a6a8a57
Add Telemetry for about:home startup cache. r=Gijs,data-review=mmccorquodale
https://hg.mozilla.org/integration/autoland/rev/23f3448ea3b8
Add tests for scenarios when the about:home startup cache isn't used. r=Gijs

Comment 8

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/10963a6a8a57
https://hg.mozilla.org/mozilla-central/rev/23f3448ea3b8

Comment 9

[Ciprian Muresan [:cmuresan], Ecosystem QA]

I have verified that the browser.startup.abouthome_cache_result scalar is collected and viewable in about:telemetry on the Firefox RC 80 (beta channel, BuildID 20200818235255), the latest Firefox Beta 81.0b1 (BuildID 20200824150741), and the latest Nightly 82.0a1 (BuildID 20200824215021) using Windows 10 x64, macOS 10.15.4, and Linux MX 4.19.
@mconley, please let me know if this verification was insufficient.