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