Computational Viewpoint

The CV for a generalised DARIAH activity contribution describes set of computational objects that could be expected to constitute an activity within the infrastructure. For each of the specific contributing activity types a subset of computational objects would normally be expected to be present in the SOA for the functionality of the contribution.

As per the CV for a generalised service, there are four groups of computational objects.

Computational Viewpoint DARIAH General Activity Computational Viewpoint DARIAH General Activity

CV Presentation Objects

Presentation objects are the entry points for human users to the services provided. The user interfaces consist of both service management and researcher (consumer) access points, or gateways.

Activity Management UI

The Activity Management User Interface provides an user interface to access the Activity Subsystem for authenticated human users with management credentials.

Computational Viewpoint Activity Management User Interface object

Support Service UI

The Support Service User Interface provides a user interface to access the Support Services Service for authenticated human users with management credentials.

Computational Viewpoint Support Service User Interface

Consumer UI

A community portal for interacting with an activity, or activities, of the distributed infrastructure.

Computational Viewpoint Consumer User Interface object

The Consumer UI encapsulates the functions required to interact with the activities provided by the research infrastructure externally to the infrastructure. It supports the following interactions:

  • request process (client): takes input from the researcher to request and start a service.
  • authenticate user (client): a client interface which requests confirmation of the identity of the user agent.

CV Service Objects

Administration Functions

These objects may be internal or external to the RI and activities, provided by an external agent such as a national authority.

User Authentication Service

The User Authentication Service is a proxy object which confirms the identity of an agent when an agent makes a request to the service (or infrastructure). As part of the (generalised) service provision it is only composed of an authentication service object.

Computational Viewpoint User Authentication Service object

The User Authentication Service is a proxy object for all actions needed to verify the identity of an agent. It supports the following interactions:

  • authenticate user (server): is a public interface for determining whether the agent is who it claims to be.
  • request user attributes (server): is a public interface for requesting provided attributes from the agent.

Activity Subsystem

The Activity Subsystem provides access to activity functions and is composed of an Activity Service object, an Activity Workbench object and an Activity Controller object. For each request to deploy an activity from an Activity Service, an instance of the Activity Controller object is instantiated by the Activity Workbench.

Computational Viewpoint Activity Subsystem

The Activity Service is a proxy object for activity subsystem, managing the activity. It supports the following interactions:

  • deploy activity (server): the public interface for the deployment of a new activity controller.

The Activity Workbench is a computational object that instantiates a new activity controller objects. It supports the following interactions:

  • create activity controller (server): is the interface for requesting a new activity controller.
  • new activity controller (instantiation): Instantiation of a new activity controller object by the Activity Workbench.

The Activity Controller is a controller object that runs the activity. It supports the following interactions:

  • configure activity (server): the public interface for configuring and managing the activity.
  • monitor activity (server): is the public interface for monitoring the activity.
  • get data (client): is the interface to get data for use in the activity.
  • post data (client): is the interface to receive data created in the activity.

Coordination Service

The Coordination Service delegates all activity tasks. It coordinates multi-stage workflows and initiates execution and manages any data flow within an activity.

Computational Viewpoint Coordination Service object

The coordination service is a proxy object for activity tasks deployed on infrastructure execution resources. It supports the following interactions:

  • process request (server): which provides functions for scheduling the execution of activity tasks.
  • coordinate process (client): is used to coordinate the execution of activity tasks on execution resources presented by activity controllers. Activity workflows may be orchestrated in this way.
  • prepare data transfer (client): This is used if data is required for or generated in a service and is moved into and out of the data store via the data transfer service.

Support Services Service

The Support Services Service provides access to services provided externally to the research infrastructure and activity. For example, catering services for an event, or software publishing services (e.g. GitHub).

Computational Viewpoint Support Services Service object

The support service is a proxy object for Support Services Service for external services. It supports the following interactions:

  • request support service (server): is the interface for initiating a support service for an activity.
  • query support (server): is the interface which provides status information about the support service.
  • get data (client): is the interface to get data for use in the support service.
  • post data (client): is the interface to receive data created in the support service.

CV Component Objects

Storage Controller

Data storage needs for an activity are significantly less complex than potentially for a service, such as, a data hosting and preservation service, thus an activity requires storage controller objects to interface with storage system used by the activity.

Computational Viewpoint Storage Controller object

The Storage Controller is a controller object that manages the storage used in an activity. It supports the following interactions:

  • get data (client): is the interface to get data from the storage system.
  • post data (client): is the interface to post data to the storage system.

CV Back End Objects

Back End Objects are objects which encompass the systems and resources provided for preserving, publishing, and processing research data through user accessible services.

Storage System

The Storage System is a system that manages and stores data and metadata of the activity in a research infrastructure.

Computational Viewpoint Storage Systems

The File Management System manages the storage and retrieval of data as files in a computer system.

The Database Management System manages the storage and retrieval of data and metadata in logically structured repository systems.

Activity Registry

The Activity Registry is an information system for registering activities within the research infrastructure.

Computational Viewpoint Activity Registry

The Activity Registry is a proxy object that encapsulates all actions needed to register, update and request activity information. It supports the following interactions:

  • register/update activity (server): is a public interface for registering an activity and any maintenance events.
  • request activity attributes (server): is a public interface for requesting provided attributes for a registered activity.