Architecture Working Group Pasquale Pagano CNR-ISTI All WGs Meeting, Rome, May 2010

The DL.org Architecture Working Group Mission – Identify interoperability issues from the perspective of Architecture – Identify possible approaches to mitigate/resolve the issues identified – Propose effective patterns towards their resolution Scope – Enable the use of Architectural Components belonging to one system (the provider) from another system (the consumer): Software Components, i.e. artefacts implementing a set of functions, System Components, i.e. running elements contributing to the operation of the overall system All WGs Meeting, Rome, May 20102

Interoperability from the Architecture Perspective 1/2 All WGs Meeting, Rome, May The place where every concept materialises

Interoperability from the Architecture Perspective 2/2 Component Architecture reuse requires a common understanding of some component features Component Architecture reuse requires communication between provider and consumer Consumer Provider All WGs Meeting, Rome, May

Architecture Interoperability Approach Common understanding and communication facets of a component are represented in the Reference Model: Component Profile, i.e. the “metadata” characterising the resource to share Application Framework, i.e. the “context” characterising the operational environment: roles, interaction patterns, interfaces and protocols 5All WGs Meeting, Rome, May 2010

Architecture Interoperability Approach: component profile Profile is used for – present the interface – represent the state – list the dependencies – represent the existence and support discovery – improve the QoS by including run-time status – represent the behavior Common approaches are based on – syntax definition in XML and XML Schema – Varieties of standards (WSDL, WSDL-S, WSRF, …) All WGs Meeting, Rome, May 20106

Architecture Interoperability Approach: application framework Component interoperability is based on – an exchange of meaningful and context driven data. This exchange aims to allow a system to use functionality implemented in other systems Component Integration aims to – the creation of a unique logical unit derived from linking together heterogeneous components in a concrete system Component interoperability among two systems happens when: – two application frameworks are interoperable – two application frameworks are reconciled to some extent All WGs Meeting, Rome, May 20107

Architecture Interoperability Approach: application framework Two application frameworks are interoperable when they use an agreed standard (or a combination of them) that achieves a certain amount of homogeneity between the involved systems Messaging Description and Discovery Reliability, Transaction, and Security Management Application-oriented All WGs Meeting, Rome, May 20108

Architecture Interoperability Approach: application framework Two application frameworks are reconciled to some extent through component mediating between the involved systems: Blackboard-based – asynchronous communication between components in a system – one protocol to R/W and one language to specify messages Connector / Adaptor-based – translates one interface for a component into a compatible interface Proxy-based – exposes the same interface but allows additional operation over received calls Mediator-based – provides a unified interface to a set of other components interfaces and encapsulates how this set of objects interact Broker-based – Specialises a mediator by coordinating communication All WGs Meeting, Rome, May 20109

Time for questions WG Coordinates: – Site – Survey of-the-art/Approaches – Mailing List – Scientific Chair Pasquale Pagano – – WG Leader & Rapporteur Leonardo Candela – All WGs Meeting, Rome, May