Hm, am trying to solve the dt. vs meta.dt client timestamp during migration issue with https://gerrit.wikimedia.org/r/c/operations/puppet/+/593610/7/modules/profile/manifests/analytics/refinery/job/camus.pp#b119 by making a new Camus job just for EventLogging that we will switch each legacy event stream to after it is fully migrated to EventGate. On more thought, this would work, but would require a manual and careful Refine during the hour that the job is switched to the new Camus job, as there would probably be data in two locations that would need to end up Refined into the table.
A smoother way would be to make Camus take a list of possible timestamp fields from which to partition. If the first is not found, the second would be used. We can then use the same Camus job configured to look for first meta.dt and then dt if meta.dt is not found. This would allow the same Camus job and raw directory to be used throughout the migration.