Extension:ArticleFeedback/Ramp-up plan

This is a rough planning for ramping up ArticleFeedback from the current ~100k pages to all main namespace, non-redirect pages (~3.6M) on English Wikipedia, starting on June 16th and ending on June 30th.

Prerequisites

• A UDP backend for ClickTracking has been written and deployed, and is working well
• We have ops around each time we increase the percentage

Schedule

• Initial ratio: 2.7% (~99k)
• Thu Jun 16: ramp up to 10% (~368k)
• Mon Jun 20: 20% (~736k)
• Tue Jun 21: 30% (~1.1M)
• Wed Jun 22: 50% (~1.8M)
• Thu Jun 23: 75% (~2.8M)
• Mon Jun 27: 90% (~3.3M)
• Tue Jun 28: 100% (~3.6M)
• Wed Jun 29: slack
• Thu Jun 30: slack

Notes

• The variable in question is $wmgArticleFeedbackLotteryOdds in InitialiseSettings.php
• It's proposed that ramp-ups be done in four increments, one every 15 minutes
• I've added two days of slack time in case we hit some issue and it takes time to fix it
• No percentage bumps on Fridays
• We will be lowering the ClickTracking percentage as well. It's OK to increase the number of events/sec once we have the UDP backend, but we don't need to track everything 100% across the board either.
• When pushing config changes, we'll also need to touch startup.js and sync that to work around bug 28899