MobiCloudTowards Cloud Mobile Hybrid Application

Generation using Semantically Enriched DomainSpecific Languages

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Ajith H. Ranabahu , Amit Sheth, Ashwin Manjunatha, Krishnaprasad Thirunarayan

The Ohio Center of Excellence in Knowledge-enabled Computing - Kno.e.sisWright State University

Ajith Ranabahu, Amit Sheth, Ashwin Manjunatha, and Krishnaprasad Thirunarayan, 'Towards Cloud Mobile Hybrid Application Generation using Semantically Enriched Domain Specific Languages', International Workshop on Mobile Computing and Clouds (MobiCloud 2010), Santa Clara, CA, October 28, 2010http://knoesis.org/library/resource.php?id=865

Agenda• What are Cloud-Mobile hybrids ?– Why are they hard to build ?

• Building Cloud-Mobile hybrids with DSLs– Pros and cons– Current DSL and tooling

• Semantic Enhancements• Our vision– Cirrocumulus project and the role of MobiCloud

• Questions

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What are Cloud-Mobile Hybrids ?

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PortableUbiquitousConnected

ScalableOn-demandEconomical

Computing PowerPortability

Spectrum of Computing Power

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Cloud-Mobile Hybrids (CMH) ?

• Applications that span over multiple devices– Back-end in Cloud – Front-end in a mobile device

• Both components needed for the app to function

• Front-end is not just a webpage !– A native iPhone / Android / Blackberry app

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Simple Example

• The Facebook App– The Facebook client you have in your smart phone !• Mobile front-end for Facebook

– Most Facebook activity happens via Mobile devices !

• Many actions need extensive processing in the Facebook backend• Both parts (back-end and the front-end) required for

the complete experience

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Another Research Oriented Example

• Privacy score1

– Introduced by IBM researchers – Measures relative exposure of private data on a social

network– Provides a similar number to “credit score”

• Requires heavy calculations in the back-end• Front-end is simply one number !– Perfect for a mobile device !

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1. A Framework for Computing the Privacy Scores of Users in Online Social Networks, Kun Liu, Evimaria Terzi Ninth IEEE International Conference on Data Mining, 2009

Are CMH Apps hard to build ?

• Yes - very much !!• Clouds are heterogeneous– Write the back-end to suit Amazon – You can’t

move to Google !!• Same in mobile devices– Need to write different apps for different devices !• Android / iPhone / Blackberry are all different

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Our solution to this Problem…

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Use a DSL

• DSL ?– Domain Specific Language – A mini language for a special purpose• Make / Ant • Matlab• Many other examples

• Use a DSL to generate an application

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What changes by using a DSL ?

• DSLs are abstract– Reduced complexity

• No separation between front-end / back-end– No service interfaces to worry about (auto

generated)• Communication interfaces – a major source of errors

and incompatibilities

– Complexity reduced further

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What changes by using a DSL ? (Cont)

• Generators take care of multiple front-ends / back-ends– Generate apps for Amazon, Google, Android,

Blackberry using one script

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A birds-eye view of what we do

DSL Script

Compiler/Generator

Cloud Mobile Hybrid Application

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Is this the silver bullet ?

• Nope !– Less control over the code• E.g. Extensive GUI customization and device integration

not possible

– Covers only the 80% case• E.g. Not suitable for games or other UI intensive

applications

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Our current DSL

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DSL design principle

• Based on Model-View-Controller (MVC) design pattern

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Model

View Controller

A very simple “Hello World”

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recipe :helloworld do metadata :id => 'helloworld-app' # models model :greeting, {:message => :string} #controllers controller :sayhello do action :retrieve,:greeting end # views view :show_greeting, {:models =>[:greeting], :controller => :sayhello, :action => :retrieve} end

Models

Controllers

Views

Metadata – details that need to be attached to the whole application

Linking the model using its unique name

Linking the controller using its unique name

Mapping of Hello World to Cloud and Mobile Spaces

Model

View Controller

Persistent Storage

UIRESTful Service Client

RESTful Service Implementation

Server side handler

Greeting Data Structures

Greeting Data Structure

Mobile Device Cloud

A slightly complicated Example (task manger)

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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} view :todo_show, {:models =>[:todoitem],:controller => :todohandler,:action => :retrieve} end

Regular development vs DSL for CMH

Regular Development• Developed as two

applications• Different platforms need

new effort.• Significant effort in creating

code and other artifacts• Highly customizable

DSL based Development• Developed as a single

application• Generators create

functionally equivalent applications for multiple platforms

• Minimum effort in creating all required artifacts

• Limited customization

Other Benefits of DSL Based Development

• Convenient integration of other features– Location based services• Integration with available location sensors, e.g GPS

– Non functional features• Security

– Social Network features• Publish to Facebook, Twitter etc

Current MobiCloud Architecture

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Blackberry Platform

Android Platform

GAE Platform

Amazon EC2

Platform

Generator 2(Blackberry)

Generator 1(Android)

Generator 3(GAE)

Generator 4(Amazon

EC2)

ParserDomain Specific Language (DSL)

Script

Web Based Graphical User Interface

Text Editor

Integrated Development

Environment (IDE) based Graphical User

Interface

Object Model

Current MobiCloud Wizard Interface

Step 1 : Write your code

Step 2 : Select the targets

Step 3 : Download the code

The downloadedcode can be compiled to create an executable application using relevantdevelopment kit

MobiCloud Tools

• Web based Editor Available at http://knoesis.org/mobicloud– Free to use

• Plans to make the code available as opensource soon !

• More details in our technical report and CloudCom papers (to be published, seeL http://knoesis.org/library)

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Switching Gears : The Modeling Space and the Role of Semantics

The edge in Semantics

• 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

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.

Typically in both server and client representing Data structures. Described In Models

Typically defines controller logic and resides in the server side. Included in both the controller and the view

Usually aspects that are layered

such as security. May be

associated with controllers as

well as metadata

Associated with the

application, typically via

the metadata tags

Partitioning of the Modeling space

Current MobiCloud DSLPlanned

coverage of MobiCloud

Where can Semantics Help ?

• Reusable Data Definitions– RDF based Platform-neutral data definitions– Reference from the app rather than redefine• E.g. Use FOAF definition for person

model: person , {:ref => “foaf:Person”}

Where can Semantics Help ? (Cont)

• Non-functional Capabilities– Attach non-functional configurations (e.g.

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

– E.g. Strength of encryption for security

Where can Semantics Help ? (Cont)

• System Configurations– Define abstract deployment / Management

configurations using semantics– Already available in Elastras Language suite• ECML, EDML, EMML

– RDF based modeling of core system aspects

DSL with Semantics

Our Vision and the Role of MobiCloud

The Cirrocumulus Project

• End-to-End coverage for Cloud application development– Develop, deploy and manage Cloud applications without

depending on specificities of any Cloud

• Use DSLs and Middleware together– Inspired by IBM Altocumulus and IBM Sharable code

projects– Use semantics as a core binding across all stages

MobiCloud fits in here

The Cirrocumulus Project

Comparison with Other Commercial Efforts

Libcloud (http://incubator.apache.org/libcloud/)

• Developer centric program abstraction over Infrastructure cloud operations

• Support in only Python and Java

Deltacloudhttp://deltacloud.org/

• Developer centric service abstraction over Infrastructure cloud operations

Cirrocumulus / MobiCloud

• Developer centric abstraction over applications and cloud operations

• Supports IaaS as well as PaaS Clouds

• Code can be generated in any language

The Cirrocumulus Project (Cont)

LibCloud / DeltaCloud can be used in building this

component

References / More details

• Technical report on MobiCloud– http://knoesis.wright.edu/library/publications/Mo

biCloud.pdf• Publicly hosted MobiCloud tool– http://knoesis.org/mobicloud

• Code repository– Coming soon !

• Privacy score paper– http://portal.acm.org/citation.cfm?id=1674659.1

67707538

Researchers

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Ajith Ranabahu

AmitSheth

Ashwin Manjunatha

KrishnaprasadThirunarayan

Time for Questions ?

More at http://knoesis.org http://knoesis.wright.edu/research/srl/projects/mobi-cloud

/ The Ohio Center of Excellence in Knowledge-enabled Computing -

Kno.e.sis

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Thank you

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