Abstract: Concepts for controlling interaction with scalable applications are presented. One example comprises associating metadata with an application interface specification of an application. Based on the metadata associated with the application interface specification of the application, configuration of shards for managing traffic of the interaction and/or integration with the application interface is controlled. Traffic is then routed to configured shards.

Abstract: A method, computer system, and computer program product for migrating a service (e.g. microservice) from using a first application programming interface version to using a second (e.g. newer or updated) application programming interface version. The method may include determining a difference between specifications of the first and second versions of the application programming interface. Historical usage of the first version of the application programming interface by the service may then be analyzed with respect to the difference so as to determine if the service meets the specification of the second version of the application programming interface. Responsive to determining the service meets the specification of the second version of the application programming interface difference, the service may be migrated from using the first version of the application programming interface to using the second version of the application programming interface.

Abstract: A method, computer system, and a computer program product for configuring application instances on scaling is provided. The present invention may include receiving a client request, wherein the client request includes one or more commands. The present invention may include determining whether the client request is to be acted on by all application instances based on a type of client request, wherein the type of client request is determined based on at least routing metadata in an application interface specification. The present invention may include determining the client request is be acted on by all application instances.

Abstract: A method, computer system, and a computer program product for coordinating requests actioned at a scalable application is provided. The present invention may include registering metadata regarding response behavior to be applied when actioning a client request to multiple application instances. The present invention may include augmenting a client request according to the metadata to provide augmented request instances to coordinate completion on a required number of response instances from the application instances to which the augmented request instances are routed. The present invention may include coordinating a status of the client request across the application instances to terminate outstanding augmented request instances when a required number of completed instances is received.

Abstract: A method, computer system, and a computer program product for coordinating requests actioned at a scalable application is provided. The present invention may include registering metadata regarding response behavior to be applied when actioning a client request to multiple application instances. The present invention may include augmenting a client request according to the metadata to provide augmented request instances to coordinate completion on a required number of response instances from the application instances to which the augmented request instances are routed. The present invention may include coordinating a status of the client request across the application instances to terminate outstanding augmented request instances when a required number of completed instances is received.

Abstract: Concepts for controlling interaction with a scalable application are presented. An example includes registering an interface specification to an application, wherein metadata is associated with the interface specification. The method then includes routing a request to instances of the application based on the metadata associated with the interface specification for the application, then combining one or more responses from the instances of the application to form an aggregate response based on the metadata associated with the interface specification for the application.

Abstract: Concepts for controlling interaction with a scalable application are presented. An example includes registering an interface specification to an application, wherein metadata is associated with the interface specification. The method then includes routing a request to instances of the application based on the metadata associated with the interface specification for the application, then combining one or more responses from the instances of the application to form an aggregate response based on the metadata associated with the interface specification for the application.

Abstract: A method, computer system, and computer program product for migrating a service (e.g. microservice) from using a first application programming interface version to using a second (e.g. newer or updated) application programming interface version. The method may include determining a difference between specifications of the first and second versions of the application programming interface. Historical usage of the first version of the application programming interface by the service may then be analyzed with respect to the difference so as to determine if the service meets the specification of the second version of the application programming interface. Responsive to determining the service meets the specification of the second version of the application programming interface difference, the service may be migrated from using the first version of the application programming interface to using the second version of the application programming interface.