You can disable the load balancer for an Oracle SOA Cloud Service instance to suspend the service instance during maintenance, or enable the load balancer to resume a service instance after maintenance.
When enabled, the load balancer forwards the requests it receives from clients to the Oracle WebLogic Server managed servers in your service instance. When disabled, the load balancer stops forwarding such requests, but instead responds with a maintenance message and the HTTP status code 503.
Note:
You cannot enable or disable the load balancer for a service instance while the service instance is being backed up.