Abstract: A method and a controller for handling a failure or change of a processing element in a virtual network are provided. The processing element includes a first stateless executable function that use a local state storage and a persistent state storage when executed on a host in the virtual network. The controller maintains the local state storage of the processing element upon removing the first stateless executable function from the processing element in response to the failure or change. The controller also creates a second stateless executable function to replace the first stateless executable function in the processing element. Then, the controller associates the maintained local state storage with the second stateless executable function for the processing element. Further, the controller initiates the second stateless executable function using the associated maintained local state storage such that the processing element resumes execution from its real-time state before the failure or change.

Abstract: A virtual network function application is to be deployed in a multi-technology virtualization environment. The multi-technology virtualization environment comprises a plurality of virtualization technologies. The application exists in a plurality of application implementations. At least one of the virtualization technologies has a preferred one of the application implementations. The deployment comprises receiving a trigger for a deployment of the virtual network function application. In response to the trigger, information is obtained about at least one optimization objective and about resource utilization in the multi-technology virtualization environment. Based on the received information, one of the plurality of virtualization technologies is selected for said deployment. One of the application implementations is also selected, and the selected application implementation need not be the preferred application implementation for the selected virtualization technology.