I think OP is wrong in their hypothesis based on the logs they share and the root cause AWS support provided them. I think the promotion fails to happen and th

I think OP is wrong in their hypothesis based on the logs they share and the root cause AWS support provided them. I think the promotion fails to happen and then an external watchdog notices that it didn’t, and kills everything ASAP as it’s a cluster state mismatch. The message about the storage subsystem going away is after the other Postgres process was kill -9’d.