void refreshIdealState() throws Exception {
    for (MockHelixAdmin helixAdmin : helixAdmins.values()) {
      helixAdmin.triggerIdealStateChangeNotification();
    }
  }
Trigger ideal state change in each dc to refresh in-mem resource-partition mapping
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixCluster.java