Semantic Centric Solutions for Application and Data ...

1 Semantic Centric Solutions for Application and Data Portability in Cloud Computing Ajith H. Ranabahu , Amit Sheth Center Wright State University 2nd IEEE International Conference on Cloud Computing and Technology Indianapolis IN. Agenda Challenges in Cloud Computing The portability problem Role of semantics and the Modelling space Use of semantics in programming for the Cloud Semantic Enhancements to a Domain Specific Language A brief overview of our vision The Cirrocumulus project Questions Cloudcom 2010 2. Challenges in Cloud Computing Cloudcom 2010 3.

2 Cloud Landscape as of Today Cloudcom 2010 4. The Vendor Lock-in Problem Once you select a Cloud then it is hard (almost impossible) to move to a different one Both Application logic as well as data ! Vertical vs Horizontal Vertical Move within the same type of Clouds Horizontal Move across different types of Clouds Cloudcom 2010 5. Objective of Our Research A methodology to develop applications in a portable manner Use Semantic technologies to streamline this process Cloudcom 2010 6. Knowing is half the battle ! A Clear Understanding of the applications Cloudcom 2010 7.

3 Four Types of semantics for an Application Inspired by the four types of semantics for Services1,2. Enables a clear separation of issues 1. Semantic Web Process Lifecycle: Role of semantics in Annotation, Discovery, Composition and Orchestration, . Amit Sheth Workshop on E-Services and the Semantic Web (ESSW'03), 12th International World Wide Web Conference, Budapest, Hungary, May 20, 2003. 2. METEOR-S Web service Annotation Framework' , Abhijit Patil, Swapna Oundhakar,Amit Sheth, and Kunal Verma, in proceedings, 13th International Conference on World Wide Web (WWW 2004), New York, NY, 2004.

4 Cloudcom 2010 8. Modeling For applications applications development is a complicated process Multiple parties / Multiple stages Many modeling approaches already available Four types of semantics need to be carried across these stages Cloudcom 2010 9. Partitioning of the Modeling space Cloudcom 2010 10. From High level models to a Concrete Grounding We need both high level modeling and running code ! High level models Easier to understand A birds-eye view Executable code Detailed and intricate May not give a clear understanding of what it does It works !

5 Cloudcom 2010 11. semantics and Domain Specific Languages Cloudcom 2010 12. Using DSLs to Develop applications DSL ? Domain Specific Language A mini language for a special purpose Make / Ant Matlab Many other examples Use a DSL to generate an Application Cloudcom 2010 13. What changes by using a DSL ? DSLs are abstract Reduced complexity Minimum separation between multiple components No service interfaces to worry about (auto generated). Cloudcom 2010 14. Why semantics ? Semantic Web community has tackled the portability problem for years !

6 Semantic models are capable of providing generic abstractions over data, functional, non-functional and system aspects Referring to these models rather than re- implementing code, significantly reduces the development effort Cloudcom 2010 15. Example The MobiCloud DSL. Generates Cloud-Mobile hybrids Capable of addressing multiple clouds as well as mobile devices Presented tomorrow in the Work In Progress track as well as the demo session. Cloudcom 2010 16. Is this the silver bullet ? Nope ! Less control over the code Extensive customization and device integration may not possible Covers only the 80% case A given DSL is only good in covering its own domain.

7 The MobiCloud DSL is not suitable for games or other UI intensive applications Cloudcom 2010 17. Using the MobiCloud DSL as a Base for semantics Cloudcom 2010 18. MobiCloud DSL. Design principle Based on Model-View-Controller (MVC) design pattern Model View Controller Cloudcom 2010 19. A very simple Hello World . Metadata details that recipe :helloworld do need to be attached to metadata :id => 'helloworld-app' the whole Application # models model :greeting, {:message => :string} Models #controllers controller :sayhello do action :retrieve,:greeting Controllers end Linking the model using # views its unique name view :show_greeting, Views {:models =>[:greeting], :controller => :sayhello, :action => :retrieve}.

8 End Linking the controller using its unique name Cloudcom 2010 20. Mapping of Hello World to Cloud and Mobile Spaces Model View Controller RESTful RESTful Service Server side Persistent UI Service handler Implementation Storage Client Greeting Data Greeting Data Structures Structure Mobile Device Cloud Cloudcom 2010 21. Breaking the Hello World with Respect to semantics recipe :helloworld do Non-functional details and metadata :id => 'helloworld-app' Metadata # models model :greeting, {:message => :string}. Data Defintions #controllers controller :sayhello do action :retrieve,:greeting end Logic and Process Definitions # views view :show_greeting, {:models =>[:greeting], :controller => :sayhello, :action => :retrieve}.

9 End Cloudcom 2010 22. A slightly complicated Example (task manger). recipe(:todolist) do # specific metadata for this app metadata({:id => todo-list'}). model(:todoitem, {:name=>:string, :description => :string,:time =>. :string, :location => :string}). model(:user, {:name=>:string, :bday => :string}). #controllers controller(:todohandler) do action :create,:todoitem action :retrieve,:todoitem action :update,:todoitem action :delete,:todoitem end # views view :todo_add, {:models >[:todoitem],:controller => :todohandler,:action => :create}.

10 View :todo_show, {:models =>[:todoitem],:controller =>. :todohandler,:action => :retrieve}. end Cloudcom 2010 23. Data semantics Reusable Data Definitions RDF based Platform-neutral data definitions Reference from the app rather than redefine Use FOAF definition for person model: person , {:ref => foaf:Person }. Cloudcom 2010 24. Non-Functional semantics Non-functional Capabilities Attach non-functional configurations ( Security) via profiles Define abstract profiles using semantics The generator can insert the necessary code May need global ( Application -wide) configurations declared in the metadata section to be applicable to the whole Application Strength of encryption for security Cloudcom 2010 25.