Organization responsible: Thales, The Netherlands

People involved:

• Maurice Glandrup, Thales

Project description:

Applications for future systems could be developed by using a component standard. A future network centric architecture, therefore, must incorporate this component standard. At this moment, a very promising standard is the CORBA Component Model (CCM). CCM is specified and controlled by the OMG. It specifies a component container. The container concept allows components that are embedded in implementations of CCM to access services that are provided by the middleware without that components are aware of the middleware or technology that must be used to address services. Here, the definition of services does not differ from the one given previously. The services that are addressed in this activity, however, are not specific to a certain business domain but are general. Therefore, they provide a Quality of Service (QoS) to the system.

To be usable in mission critical systems, the network centric architecture imposes some constraints on the CCM. Two constraints that Thales-Hengelo addresses in this activity are Fault Tolerance and Data Distribution. Both constraints are, already, specified as services by the OMG. They are called Fault Tolerant Service and Data Distribution Service, which provide a QoS concerning fault tolerance and data distribution, respectively. The Fault Tolerant Services allows components to go into a known state upon a failure in/of the system. This prevents the system and its data to become inconsistent. The Data Distribution Service (DDS) allows components to distribute its data to other components in a real-time manner.

To enable components to benefit from the QoS characteristics of these services, they must be integrated in the CCM. This activity focuses on:

• Are existing Fault Tolerant Services sufficient to be used in mission critical systems.  Here the focus is especially on the evaluation of the Fault Tolerant service that is provided by another Thales unit. If the service does not suffice, then additional requirements must be provided and a proof of concept must be developed
• The integration of the DDS in the CCM.

At this moment, CCM provides a service oriented way and an event oriented way of communicating to components. Service oriented communication means that a component can address a service; usually this is a request-reply mechanism. Event oriented communication means that components are notified when a certain event is raised. The component can then use a service to react on the event. The DDS provides a third way of communicating for components, a data oriented way. The service is used to publish data and to subscribe to data without knowing what components use the data and what other components also produce the data. Integrating a new communication mechanism in CCM means extending CCM in the implementation and at modeling level. At modeling level designers of components need to be able to express the communication mechanism that is used.

Publications: (none)