1515132 - Add telemetry for FirstContentfulPaint

Status: RESOLVED FIXED

(Core :: Performance, enhancement)

Description

[Randell Jesup [:jesup] (needinfo me)]

We need to add telemetry for FirstContentfulPaint.

There should be no privacy or fingerprinting implications.

Comment 1

[Randell Jesup [:jesup] (needinfo me)]

Attachment: Add telemetry for FirstContentfulPaint data-review=chutten

Mirrored on the NonBlankPaint telemetry.  Does not include the NETOPT variants added by Honza for trialing network optimizations; we can add that as a separate bug if needed

Comment 2

[Chris H-C :chutten]

Comment on attachment 9036432 [details] [diff] [review]
Add telemetry for FirstContentfulPaint data-review=chutten

Review of attachment 9036432 [details] [diff] [review]:
-----------------------------------------------------------------

This new data collection will require [Data Collection Review](https://wiki.mozilla.org/Firefox/Data_Collection) before it lands.

From a "technical use of Firefox Telemetry" POV it looks fine. 

To me 100s looks like an awfully long time to be waiting for a contentful paint. The increased resolution a high of 60000 would bring ([high of 100s](https://telemetry.mozilla.org/histogram-simulator/#low=1&high=100000&n_buckets=100&kind=exponential&generate=log-normal) vs [high of 60s](https://telemetry.mozilla.org/histogram-simulator/#low=1&high=60000&n_buckets=100&kind=exponential&generate=log-normal)) might be worth the lack of being able to distinguish between "really bad" (60s) and "horrifyingly bad" (100s) but I'm not a domain expert and it seems as though there might me some benefit to having it be consistent.

I bring it up in case it might be helpful. It's likely fine for most purposes as-is.

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

Attachment: FirstContentfulPaint data collection

Comment 4

[Chris H-C :chutten]

Comment on attachment 9041871 [details]
FirstContentfulPaint data collection

DATA COLLECTION REVIEW RESPONSE:

    Is there or will there be documentation that describes the schema for the ultimate data set available publicly, complete and accurate?

Yes. This collection is Telemetry so is documented in its definitions file ([Histograms.json](https://hg.mozilla.org/mozilla-central/file/tip/toolkit/components/telemetry/Histograms.json)) and the [Probe Dictionary](https://telemetry.mozilla.org/probe-dictionary/).

    Is there a control mechanism that allows the user to turn the data collection on and off?

Yes. This collection is Telemetry so can be controlled through Firefox's Preferences.

    If the request is for permanent data collection, is there someone who will monitor the data over time?

Yes, two: Randell Jesup and Vicky Chin.

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

Category 2, Interaction. (insofar as the count of these paints is the count of pages loaded)

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

Default on for all channels.

    Does the instrumentation include the addition of any new identifiers?

No.

    Is the data collection covered by the existing Firefox privacy notice?

Yes.

    Does there need to be a check-in in the future to determine whether to renew the data?

No. This collection is permanent.

---
Result: datareview+

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/134b85ae973c
Add telemetry for FirstContentfulPaint data-review=chutten r=mstange,a=chutten

Comment 6

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/134b85ae973c

Comment 7

[Randell Jesup [:jesup] (needinfo me)]

Comment on attachment 9036432 [details] [diff] [review]
Add telemetry for FirstContentfulPaint data-review=chutten

Beta/Release Uplift Approval Request

Feature/Bug causing the regression

None

User impact if declined

Less data on FCP for a release

Is this code covered by automated tests?

Yes

Has the fix been verified in Nightly?

Yes

Needs manual test from QE?

No

If yes, steps to reproduce

List of other uplifts needed

None

Risk to taking this patch

Low

Why is the change risky/not risky? (and alternatives if risky)

Just adds a telemetry point

Data looks reasonable: https://telemetry.mozilla.org/new-pipeline/dist.html#!cumulative=0&end_date=2019-02-14&include_spill=0&keys=__none__!__none__!__none__&max_channel_version=nightly%252F67&measure=TIME_TO_FIRST_CONTENTFUL_PAINT_MS&min_channel_version=nightly%252F63&processType=*&product=Firefox&sanitize=1&sort_by_value=0&sort_keys=submissions&start_date=2019-02-12&table=0&trim=1&use_submission_date=0

String changes made/needed

none

Comment 8

[Markus Stange [:mstange]]

If we uplift this, we should also uplift bug 1506976, otherwise we won't be able to compare numbers between Beta and Nightly.

Comment 9

[Liz Henry (:lizzard) (relman/hg->git project)]

Comment on attachment 9036432 [details] [diff] [review]
Add telemetry for FirstContentfulPaint data-review=chutten

Support for measuring page load/rendering times, OK for uplift to beta 8.

Comment 10

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/releases/mozilla-beta/rev/4c4ff2febd83