+ /**
+ * Method has to activate (MASTER) or deactivate (SLAVE) TransactionChainManager.
+ * TransactionChainManager represents possibility to write or delete Node subtree data
+ * for actual Controller Cluster Node. We are able to have an active TxManager only if
+ * newRole is {@link OfpRole#BECOMESLAVE}.
+ * Parameters are used as marker to be sure it is change to SLAVE from MASTER or from
+ * MASTER to SLAVE and the last parameter "cleanDataStore" is used for validation only.
+ * @param role - NewRole expect to be {@link OfpRole#BECOMESLAVE} or {@link OfpRole#BECOMEMASTER}
+ */
+ ListenableFuture<Void> onClusterRoleChange(@CheckForNull OfpRole role);
+