© datamat s.p.a. – 2007 1 giuseppe avellino, stefano beco, barbara cantalupo, andrea cavallini a...
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© DATAMAT S.p.A. – 2007 1
Giuseppe Avellino, Stefano Beco, Barbara Cantalupo, Andrea Cavallini
A Semantic Workflow Authoring Tool for Programming Grids
Workflows in Support of Large-Scale Science Workshop
23th June 2007
© DATAMAT S.p.A. – 2007 - 2 -
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Outline
NextGRID Project Workflow Programming Model Workflow Language Requirements Semantic Workflow Landscape OWL-WS Ontology Language Semantic Workflow Programming Tool
(SWPT) Conclusions Future Plans
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NextGRID Project This work is part of NextGRID project, an FP6
EU Funded Project The objective is to define a Next Generation
Grid (NGG) architecture This work is in the context of dynamic aspects
of Grid systems: how services and clients interact to enable federation of resources, services and users between disparate domains
Grid Virtual Infrastructure Model (Grid VIM) Makes the Grid infrastructure adaptable to the needs
of different actors Provides a consistent interface for application
developers and users
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Workflow Programming Model Workflows play an important role in the process of
turning from the Grid technology infrastructure to the Business Process Management environment
Workflows can be considered as a Programming Model for service components composition and can support process flexibility by soft-coding application behaviour
Representation of the interactions between software components and people in a business process is best done in terms of workflows
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Workflow Life-cycle
Application User
Application Developer
Service Provider
Procurement Manager
Budget Holder
Editing ApplicationWorkflow
Editing ProcurementBusiness Workflow
Editing ProvisionBusiness Workflow
Execute Application
Execute ProvisionProcess
Service Manager
Deploy Servicewith Workflows
Define Application
Execute ProcurementProcess
<<include>><<include>>
Authoring
Enactment
Publication
ISV
Provider
Consumer
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Workflow Language Requirements
Abstract workflows definition: abstract workflow composition possible without specifying a grounding (run-time grounding)
Semantic task description: each task has a description or type/function
Workflow substitution: a grounding could be a workflow itself
Higher-order workflows management: a task can take a workflow as input and return another workflow for execution
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Semantic Workflow Landscape
Formal Models
Grid Architecture
WorkflowWorkflow
Semantics
UML, BPMN, ...
WSDL.BPEL4WS, ...
Petri Nets, Pi Calculus, Turing Machine,... SAWSDL
....OWL-S,WSMO,WSDL-S,SWSF....
Grid Projects
Web Services
WSRF
Business Models
Business Process Management
WS-CDL
WSBPEL
eBXML
XPDL
Workflow Patterns
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Semantic Workflow Landscape There are a lot of semantic workflow research fields
which can provide some different solutions for specific needs
We chose to extend OWL-S because we focused on semantic (innovative aspects)
We also consider the possibility of BPEL + semantic, but BPEL had not Abstract Processes and was quite complicated
We were looking for a simpler solution We also focused on defining something general, a
Semantic Model, to investigate the semantic field and apply results also to other technologies and languages
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OWL-WS Ontology Language OWL-WS (OWL for Workflows and Services) is an
extension of the OWL-S language OWL-WS
satisfies the workflow language requirements extends the concept of Service to Abstract Process uses the OWL-S Composite Process concept for workflow modelling allows to assign a Profile to any Process
OWL-S was proposed
as a standard
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Semantic Workflow Programming Tool
The SWPT is a graphical framework to model and edit semantic workflow in different application domains
The SWPT is modular and designed on the base of the Reference Workflow Model
It is designed to be as much as possible language independent
It enables multiple business roles: application developer, end user, end users’ procurement authority and service provider
It provides interface to Grid Infrastructure Services (Service Discovery, VO and SLA management, Security, etc)
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Semantic Workflow Programming Tool Framework The framework is composed of the following
components: Workflow Model Management Framework
The core of the SWPT, it implements the internal workflow programming model, I/O, graphical and language interface
Authoring Framework GUI for workflow editing, validation and external interaction
Semantic Framework It provides tools and APIs for managing ontology
Deployment Framework Services publication
Workflow Representation Framework Interface external enactment system
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Semantic Workflow Programming Tool Framework
Workflow Model Management Framework
Authoring Framework
Workflow Representation Framework
Grid VIM / Target Enactment Systems Interface Framework
Deploym
ent Fram
ework
Sem
antic
Fra
mew
ork
Interface (API)
Shared ComponentsTool + API for Ontology
Management
•Editing
•Validation
•External Interaction
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Service is the basic workflow component A Semantic Grid Service is defined and managed using some
kind of semantic information
Self-Similarity Service and Workflows are similar entities from different level
perspective
Abstraction Services can be described as Abstract or Concrete
Workflow Model Management Framework
A Service is a very Simple WorkflowA Service is a very Simple Workflow
A Workflow can be exposed as a ServiceA Workflow can be exposed as a Service
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Workflow Model Management Framework
Properties (Profile information - functionality) Functional
Input, Output, Precondition, Result Non Functional (semantic)
Constraint is information on required properties of the services Capability is information on the properties provided by the service
Process (Process information – structure) Control Flow, Data Flow, Events
Execution Implementation info (Service endpoint)
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Semantic Framework The Semantic framework enables users
accessing information on the specific application or business domain
Knowledge management is complex and it makes sense if the form it is represented is commonly understood
Each domain can be described by ontology with a shared vocabulary and a set of task templates
A task template is a service or a workflow that describes a function, inputs, outputs, parameters and semantic information
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Authoring Framework
Authoring phases:Ability to retrieve definition of services in a
specific domainAbility to compose selected services in
workflows, providing information on data and control structure
Ability to specify additional information for each service or workflow
Abstract services/workflows can be used to compose more complex workflows
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SWPT GUI
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SWPT GUI
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Conclusions We presented a Semantic Workflow
Programming Model The language adopted is OWL-WS, but
also other languages could be supported Looking at the past and future languages
evolution, the SWPT language independence is of great value
Final release of the tool in NextGRID context will be provided at the end of the year
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Future Plans New parsers could be developed in order to
support new languages The tool is now integrated with the VIM to
provide enactment and monitoring of the workflow, but other enactment systems are possible
We are working on improving the workflow execution monitoring
The tool will be also used in the context of the EU Brein project, and enhancements will be provided
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References and Contacts This work has been supported by the NextGRID
project (contract number 511563), which is co-funded by the European Commission's IST programme of the 6th Framework Programme http://www.nextgrid.org/
Contacts {giuseppe.avellino, stefano.beco, barbara.cantalupo,
andrea.cavallini}@elsagdatamat.com
Thank you!Thank you!