No migration changes are required for BlackBerry Hybrid Apps; however, you might need to make some changes to take advantage of new features, or when you modify an application.
Scale-out nodes take requests only from messaging clients (OData SDK, Hybrid Web Container) and HTTP clients (REST APIs). For these clients to connect to the scale-out node, clients must be built with Unwired Platform version 2.2. Only 2.2 clients can fully support HTTP cookies. You must migrate existing clients to version 2.2 if you want to connect to scale-out nodes. For details about cookie support, see the corresponding Developer Guide for your client type.