Initializing subsystems such as flow control and the Rebalancer.
Synchronizing global cluster state, including internal system catalogs and global variables.
Resolving (or re-resolving) in-process transactions, including rolling back transactions that were interrupted by the Group Change.
Invalidating or rebuilding internal caches, such as the Query Plan Cache.
Creating recovery queues for downed replicas, or "flipping" queues that are no longer needed.
Resizing device files if necessary.