Take 3 as this is the third investigation of holes.
Holes identified in T219301#5844113
- Holes are less likely to happen (transactions)
- Details of the split between transactions and new job etc are documented
- "Restore" code after insertion is confirmed to do everything it needs to do
- Deadlock situation is observed after deployment (hopefully it decreases) see https://logstash.wikimedia.org/goto/956ac31f9e47b1a4a579e4f39c300b2f (should comment on this ticket with what happens)