grid-based interoperability of workflow systems moustafa ghanem, inforsense ltd nabeel azam mike...
Post on 19-Dec-2015
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SIMDAT SIMDAT
Grid-based interoperability of workflow systems
Moustafa Ghanem,
InforSense Ltd
Nabeel Azam Mike Boniface
InforSense Ltd IT Innovation
SIMDAT SIMDAT
Background: SIMDAT
• Developing and applying Grid technology to support• Distributed, Cross-organizational, product and process development
Four sectors of international economic importance:
Automotive
Pharmaceutical
Aerospace
Meteorology
Seven Grid-technology development areas:
Grid infrastructure
Distributed Data Access
VO Administration
Workflows
Ontologies
Analysis Services
Knowledge Services
www.simdat.org
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S7 S8 S9S4 S5 S6S1 S2 S3
SOA and Workflows: A programmer’s view
ToolsData
Services Services Services
Service Provider I Service Provider II Service Provider III
ToolsDataToolsData
Organization I Organization II Organization III
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Key challenge for workflow in SIMDAT
• There are 26 partners in SIMDAT
• At least 3 workflow systems in use – InforSense KDE– Taverna/Freefluo– LMS Optimus– Other approaches include
• Various hard-coded wf applications• BPEL
• Agreeing/Using a common workflow system (or language) is difficult– Migration may require huge re-investments– Continued debate on open source vs. proprietary
• In general, virtual organizations are dynamic– What happens when we add new partners?
Capability Providers
Grid Technologists
End Users
SIMDAT partners
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Workflow systems quick comparison
Similarities– All have drag-drop GUIs– All use XML-based languages– Similar conceptual model
Differences– Different language paradigms/semantics
• Pure Data Flow vs. Control Flow– Iterations (not available, implicit, explicit ?)
• Data types and operators supported– Varying degrees of abstraction
• Node granularity• Service call vs. abstract task
– Different systems specialized to particular applications• Specialized viewers• Specialized helper nodes for data manipulation
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Calling Grid Services vs Web Services
Call Grid Service
Call Grid Service
Call Grid Service
Remote Grid Service Remote Grid Service Remote Grid Service
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Example: Using of GRIA services
• GRIA uses a fully decentralized management approach, with minimal dependency between sites.
• Each site offering GRIA services makes its own business decisions about which users to trust and on what terms, and is responsible for enforcing its own access policies and deciding which applications to support.
• Sites can interact with each other, but this is driven by their common consumers, and those consumers are responsible for managing the resulting dependencies.
• There are no global agreements to set up, and no virtual organizations need be established, though users can interact according to virtual organization models if they want.
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Example: Pharma application
Five basic Sub-workflow nodes
1. Allocate Resources
2. Upload Inputs
3. Execute
4. Retrieve Result
5. Finish Conversation
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Grid-based workflows and interoperability
Run-time interoperability
– Workflow-based applications as services
– Workflow enactment as services
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Interoperability interaction patterns
(a) Chained Process Model (b) Nested Sub-process Model
(c) Parallel Synchronized Model (d) Polling Synchronized Model
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Overall approach
• User specifies high-level steps
• Steps iteratively instantiated using services and workflow templates
• Use service registries and workflow warehouses
• Use existing run-time interoperability mechanisms
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Architecture
• Heterogeneous workflow warehouse
– InforSense Workflow warehouse
• Service Registries– NEC Semantic Broker
• Authoring advisor: high-level steps for application domains
• Authoring assistant: map from abstract tasks to workflow fragments and services