Reference Architecture


 

The Cloud4SOA project introduces a broker-based reference architecture consisted of five layers:
  • The Front-end layer supports the user-centric focus of Cloud4SOA and the easy access of both Cloud-based application developers and Cloud PaaS providers to the Cloud4SOA’s functionalities exposed via widgetized services which are adaptable to the user’s context.
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  • The Semantic layer is the backbone of the architecture that puts in place the Cloud semantic interoperability framework (CSIF) and facilitates the formal representation of information (i.e. PaaS offerings, applications and user profiles). It spans the entire architecture resolving interoperability conflicts and providing a common basis for publishing and searching different PaaS offerings.
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  • The SOA layer implements the core functionalities offered by the Cloud4SOA system such as PaaS offering discovery and recommendation (matchmaking), PaaS offering and application publication (profile  management), application deployment, monitoring and migration.
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  • The Governance layer implements the business-centric focus of Cloud4SOA where Cloud PaaS providers and consumers (Cloud-based application developers) can establish business relationships through Service Level Agreements (SLA). Specifically, it enables the lifecycle execution and management of Cloud-based  applications taking into account monitoring information, SLAs and scalability issues.
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  • The Repository layer acts as an intermediary between the Cloud4SOA system and the various PaaS offerings allowing the applications to be independent from  specific PaaS offering implementations. Moreover, it provides a harmonized API that enables the seamless interconnection and management of applications across different Cloud PaaS offerings, using PaaS-specific adapters deployed in each platform.