Full paper is available from https://hal.archives-ouvertes.fr/hal-01845976

1. Towards Scalable Model Views on
Heterogeneous Model Resources
ACM/IEEE 21st International Conference on
Model Driven Engineering Languages and Systems
October 19, 2018 - Copenhagen, Denmark
Hugo Bruneliere, Florent Marchand de Kerchove,
Gwendal Daniel, Jordi Cabot

2. ● Engineering of complex systems (e.g. CPSs)
○ Models have different nature, number or size
○ Need for views combining these models
● EMF Views for building/handling views over
heterogeneous EMF models
○ Relies on a model virtualization mechanism
○ Works quite well on models of reasonable size
● What about scalability in more realistic scenarios?
○ Industrial applications with larger scale models
coming from different data sources...
Context & Problem
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3. ● A conceptual integration approach combining model views
and model persistence solutions
● A practical realization of this approach with
○ EMF Views - model view framework
○ NeoEMF & CDO - model persistence frameworks
● An evaluation of the approach + implementation in a
realistic use case from the MegaM@Rt2 European project
Contributions
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4. Motivation from MegaM@Rt2 (1/3)
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5. Motivation from MegaM@Rt2 (2/3)
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6. Motivation from MegaM@Rt2 (3/3)
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7. Integration Approach - Base Situation
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8. Integration Approach - Proposition
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9. Integration Approach - Implementation
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10. ● Building views on heterogenous model sources
○ Platform-specific initialization code for NeoEMF and
CDO (e.g. URL, ResourceFactory, data store config.)
● Persisting the view information in a scalable way
○ Initializing a NeoEMF database backend (instead of
standard XMI model serialization)
● Optimizing the view loading and element access
○ Early exits in collection navigation (e.g. EList), more
lazy loading for virtual references in EMF Views core
● Optimizing the view querying...
Integration Approach - Challenges
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11. Zoom on View Querying Optimization
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12. ● Two versions of the same view
○ Fully file-based - standard EMF-XMI
○ Mix of file and database resources
■ Requirement and Component models → EMF-XMI
■ Runtime model + view-specific data → NeoEMF
■ Java source code model → CDO
● Three complementary benchmarks
○ View creation, view loading and view querying
○ Model size from 10¹ to 10⁶ elements
Evaluation (1/2)
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13. ● Main observations
○ Slower and more memory-consuming to create the
view-specific information than XMI (as expected)
○ 4x faster than XMI for loading a 10⁶ view
○ 3x to 42x slower than XMI for navigating
○ Slower than XMI for querying (as expected)
■ Up to 6x speedup by specializing OCL queries...
Evaluation (2/2)
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14. ● Use of a common modeling API (provided by EMF)
○ Base integration was relatively straightforward
■ EMF Views + NeoEMF + CDO
○ Capabilities/features (from these tools) can be hidden
■ Efficient APIs not available from the generic API
○ Impacts of some actions can be hidden
■ API default behavior may lead to surprising (and
costly) effects
■ More elaborated delegation strategies have to be
envisioned to get more benefits...
Lessons Learned
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15. ● Quite significant number of model view approaches
○ Cf. https://hal.archives-ouvertes.fr/hal-01590674
○ Not so many proofs of their scalability
● Few approaches integrating models from different sources
○ If they do, they have other limitations (e.g. querying)
● Model composition or decoration approaches
○ Limited optimization strategies for different backends
● Interesting work available on the model querying side
○ Incrementality, data warehouse, etc.
○ Possible extensions of our approach...
Related Work
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16. ● Extend the optimized querying support (for OCL but also
using other transformation languages)
■ Cf. the Mogwaï approach for instance
■ Cf. capabilities provided by VIATRA
● Connection with other modeling APIs, environments or
model/data sources?
■ KMF, Epsilon, etc.
● In MegaM@Rt2 project… more applications!
■ E.g. on systems having physical parts (CPS)
Future Work
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17. Fork us: https://github.com/atlanmod/emfviews
Check out the paper: https://hal.archives-ouvertes.fr/hal-01845976
hugo.bruneliere@imt-atlantique.fr , florent.marchand-de-kerchove@imt-
atlantique.fr
gdaniel@uoc.edu , jordi.cabot@icrea.cat
Thanks for your attention!
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