Add a section for service load balancer cleanup

content/en/docs/concepts/services-networking/service.md

@@ -419,6 +419,8 @@ and `.spec.clusterIP:spec.ports[*].port`. (If the `--nodeport-addresses` flag in
 
 ### Type LoadBalancer {#loadbalancer}
 
+TODO(@MrHohn): Placeholder for load balancer finalizer feature
+
 On cloud providers which support external load balancers, setting the `type`
 field to `LoadBalancer` will provision a load balancer for your `Service`.
 The actual creation of the load balancer happens asynchronously, and

content/en/docs/tasks/access-application-cluster/create-external-load-balancer.md

@@ -194,6 +194,24 @@ Known issues:
 
 {{% capture discussion %}}
 
+## Load Balancer cleanup
+
+In usual case, the correlating load balancer resources in cloud provider should
+be cleaned up soon after a LoadBalancer type service is deleted. But it is known
+that there are various corner cases where resources can be leaved orphaned after
+a service is deleted. Finalizer Protection for Service LoadBalancers was
+introduced to prevent this from happening. By using finalizer, this feature
+makes sure service resource is not fully deleted until the correlating load
+balancer resources are deleted.
+
+Specifically, a finalizer with name `"service.kubernetes.io/load-balancer-cleanup"`
+will be attached to the service if any load balancer resource is created for it.
+The finalizer will only be removed after load balancer resource is cleaned up.
+Above ensures resource won't be leaked even in corner cases.
+
+This feature was introduced as Alpha in kubernetes v1.15. It can be enabled via
+feature gate `ServiceLoadBalancerFinalizer=true`.
+
 ## External Load Balancer Providers
 
 It is important to note that the datapath for this functionality is provided by a load balancer external to the Kubernetes cluster.