Described herein are technologies directed to cluster group change preparation techniques. Prior to a cluster group change operation, such as a merge or a split of a node with a group, a notification of a planned group change operation can be sent to the nodes of a group. In response to the notification, the nodes of the group can perform group change preparation operations disclosed herein. The group change operation can be blocked while the group change preparation operations are underway. The group change operation can proceed after the nodes of the group indicate completion of the group change preparation operations.