Integration and Interoperability Facilities Framework: Client Libraries

Client Libraries

Work withing CL layer of the Integration and Interoperability framework focuses on a subset of the client libraries found within the system, those that mediate access to some of the system services. The CL Model documents best practices and guidelines for all the cross-cutting concerns that transcend the semantics of individual target services. It distinguishes the concerns that relate to CL design from those that relate to CL management and evolves two separate models for their structuring: the Design Model and the Management Model. The final objective is to promote consistency across CLs towards the Framework integration.

Client Libraries Design Model

The Design Model for CL addresses cross-cutting design concerns within the system libraries, that include at least the following issues: scoped calls (how scope information is to be added to client calls), secure calls (how security information is to be added to client calls), endpoint management (how services ought to be referred to, discovered, and selected), addressing, discovery, replica management, caching, asynchronous operations (how asynchronous operations ought to be implemented), callbacks, futures, notifications, streamed/bulk operations (how streamed/bulk operations ought to be implemented), fault handling: how should faults be handled.

• Throughout these concerns, driving design principles are: simplicity, testability, evolvability and, where appropriate, standards compliance.
• Consistency is more readily and conveniently achieved through shared implementations of common solutions. In this sense, the work within the framework evolution will also be concerned with the delivery of new system components that support the development of CLs. It is expected that these Support Libraries will form a framework for CL development.

Client Libraries Management Model

Management Model: The model for CL management will address at least the following (inter-related) issues:

• module structure: relationship between CL modules, stub modules, and service modules
• build outputs: what secondary artifacts are associated with CLs
• release cycle: how are CLs released with respect to target services
• change management: how changes in target service API should be handled
• profiling and deployment: how should CLs be profiled for dynamic deployment
• distribution: how should CLs be packaged for distribution

Client Libraries Framework

The CL Framework covers the basic functionality described in the CL Model. The Framework adheres to the principles stated by the CL Model towards the Integration and Interoperability objectives.