Looking at the dashboard for app events - we have a serious and large decrease in events starting around July 28, 2016 (for android) as evidenced by this image (below) and this check-in. This appears to have been an update done to the schema but we didn't know about it.
For iOS, it appears that a drop in those events occurred earlier (around March 9, 2016) and have steadily decreased since then.
We'll need to figure these things out and get them fixed.
Specifically, the iOS app uses schema revision #10641988 (see this) but the Android app now uses schema revision #15729321 (see this) and our data collection script only reads events from MobileWikiAppSearch_10641988, which is now only receiving events from iOS app and pre-June 28th Android app.
^ @chelsyx btw in the future this is how we'd figure out this problem
Yep, I can confirm that the current production Android app is using revision #15729321. Apologies for not giving a heads-up when it was updated.
The initial iOS drop in March was due to the 5.0.0 release and the switch from "opt-out" to "opt-in" event tracking for users.
No harm no foul! :) We should be able to backfill because it's within the 90 day window.
Do you know of any methods you can recommend for watching particular files in git repos? Like if I wanted to subscribe to changes to SearchFunnel.java and WMFSearchFunnel.m to get notified of revision # updates?
Change 305736 had a related patch set uploaded (by Bearloga):
Combine MobileWikiAppSearch revisions
@debt: Will try to backfill since the affected date range is within the 90 day window. If for some reason we can't, will note the drop for Android.
For iOS, will just note that the iOS app has an opt-out feature which might partially explain that drop.