A service controller receives an operation request for a service for a consumer node of a communication network, the operation request including a context identifier referring to a context related to the operation request. The service controller forwards the operation request to a first service instance set being identified by the service controller as handling the context related to the operation request. Responsive to determining that the first service instance set is unreachable or unavailable, the service controller selects a second service instance set as a candidate to handle the context related to the operation request. The operation request for the service is then forwarded to the second service instance set.