Investigate Missing Pings

[Sdaswani]

Added by @bbinto

Why/User Benefit

• We need to make sure to properly catch and collect pings and don't miss pings, otherwise we can't properly understand how users using the product

What

• Investigate and confirm that ping count is accurate

Acceptance Criteria (how do I know when I’m done?)

• SQL query below shows less missing pings

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https://sql.telemetry.mozilla.org/dashboard/core-ping-sequence-numbers-count-per-day

This chart shows that Firefox TV is missing sequential pings every day - we need to see if how we configured sending pings is leading to this, as Focus Android seems to be sending sequential pings just fine:

[dnarcese]

From my initial investigation, it appears that we are configuring everything correctly. I filed https://bugzilla.mozilla.org/show_bug.cgi?id=1536870 for data team to investigate further on their end. After their investigation, we will hopefully have a better idea of what is going wrong and where to look.

[dnarcese]

Some ideas for where the missing pings are happening:

• ~app crashes~
  • the sequence number gets incremented when the ping is queued, which would not occur if onStop is not called (as in the case of a crash)
• ~app going to sleep~
  • verified that TelemetryIntegration#stopMainActivity, which schedules the ping upload, does get called on sleep
• copycat apps
• failed uploads are never properly re-uploaded

[mcomella]

Maybe there is something that is different about these devices that prevents the telemetry library from working correctly, e.g.:

• Smaller disk size
• On Echo Show, when the app is timed out, the app is killed without going through onStop: maybe onStop doesn't get called when apps are killed on Fire TV either