**To promote a cache cluster to the primary role** This example promotes the cache cluster *mycluster-002* to the primary role for the specified replication group. Command:: aws elasticache modify-replication-group --replication-group-id mycluster \ --primary-cluster-id mycluster-002 --apply-immediately The nodes of all other cache clusters in the replication group will be read replicas. If the specified group's *autofailover* is enabled, you cannot mannualy promote cache clusters.