Policy-driven DevelopmentLeveraging Rich Services to Empower Stakeholders
Barry Demchak ([email protected]) & Ingolf KrügerCalifornia Institute for Telecommunications and Information Technology, San Diego Division
Problem
Cyberinfrastructure (CI)† † context• 100s of stakeholders (e.g., producers,
consumers, operators, etc.)• Stakeholders opt in only when CI
satisfies their requirements• Requirements frequently change &
often mis-implemented• CIs have long delivery times
Consequence• More stakeholders requirement
churn, even longer delivery timesContradiction
• More stakeholders fewer stakeholders opt in∴ lower likelihood CI will satisfy community requirements
Result• CI underserves stakeholders
Solution
CI as scaffolding supporting:• basic data and control flows• high availability & reliability• scalability (bandwidth/storage/…)
Policy definition/execution• stakeholder authorable• injected directly into CI• constrains/augments data & control
flows
Challenges
Requirement elicitation• Enable stakeholders to articulate
requirements as policies• Enable complex/compound policies
Policy enactment• Refine policies into executable code• Compose and coordinate policy
executionPolicy deployment
• Verify completeness/correctness• Maintain system consistency
This material is based upon work supported by the National Institutes of HealthUnder Grant No 1U01CA130771-01 (Project PALMS: Kevin Patrick, PI)
and the National Science Foundation under Grant No CNS-0932403
f
† †Cyberinfrastructures (CI) f
f
†PALMS ReferencesPhysical Activity Location Measurement System to understand where activity-related energy expenditure occurs in humans as a function of time and space. Harvests data from wearable devices on small and large scales, provides framework for research and analysis, and has ultimate goal of discovering methods for engineering better health.
An Internet-based research computing environment that supports data acquisition, data storage, data management, data integration, data mining, data visualization, and other computing and information processing services. Different stakeholders produce, consume, manage, and govern a CI, and their requirements must be simultaneously met or else the integrity of the CI degrades.
1. J. Juerjens. Security Systems Development with UML. Springer-Verlag Berlin Heidelberg, 2003.2. T. Lodderstedt, D. Basin, and J. Doser. SecureUML: A UML-Based Modeling Language for Model-Driven Security. Proceedings
of the 5th International Conference on The Unified Modeling Language. pp426-441. Springer Verlag, 2002.3. M. Arrott, B. Demchak, V. Ermagan, C. Farcas, E. Farcas, I. H. Krüger, and M. Menarini. Rich Services: The Integration Piece
of the SOA Puzzle. In Proceedings of the IEEE International Conference on Web Services (ICWS), Salt Lake City, Utah, USA. IEEE, Jul. 2007, pp. 176-183.
4. A. Bhattacharjee and R. Shyamasundar. Activity Diagrams: A Formal Framework to Model Business Processes and Code Generation. Journal of Object Technology. Vol 8, No 1, Jan 2009.
5. M. Fowler. Domain-Specific Languages. Boston, MA: Addison-Wesley, Pearson Education, Inc. Sept 2010.6. K. Jensen and L. Kristensen. Coloured Petri Nets: Modeling and Validation of Concurrent Systems. Berlin: Springer-Verlag.
2009.
Techniques
Model-driven engineering• Stakeholders specify policies
directly1,2 on workflow models (UML Activity Diagrams4) using visual Domain Specific Language (DSL5)
• Refinement follows Rich Service3 decomposition & logical/deployment transformation
• Policies specify alternate workflows & data flow transformations
• Model checking using CPN Tools6
Service Oriented Architecture-based execution & deployment• Leverage standard patterns3:
strategy, messaging, routing, & composite pattern
• Leverage role-based interaction, choreography & interceptor techniques
PALMS† Case Study
Sensor Data Data Storage Calculations Visualization
Overall Requirements
Register with Study Add to Device ListUser, Dev
List Devices Select Device Add to StudyUser, DevUser User,
Devs
Create Study Add Device
Return Error
1: Only RA can add device
2: User ∈ {“RA”}
3: User ∈ {“RA”} è normal flow, else error flow
PALMS-CIService Data Connector
User
Access Policies
Study
GlobalDeviceListStudy
Service Data Connector
StudyDeviceList
3a. Constraint finally expressed as interceptor on data flow
1.Stakeholder expresses constraint on high level workflow activity 2.Constraint is re-
expressed in each workflow refinement
Conditional replacement of data flow or control flowA Policy is …
Refinement Driven by …Rich Service
Decomposition
3b. Policy executed by Interceptor
OK
Study GlobalDeviceList
AddDeviceToStudy
User PALMS-CI
AddStudyOK
GetAvailDevices
AvailDeviceList
AddDeviceToStudy
OK
Select Device
StudyDeviceList
AddDeviceToStudy
OK
GetAvailDevices
AvailDeviceList
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