1. Emergent Middleware to
Support Interoperability in
Mobile Collaborative Applications
Valérie Issarny, Inria PRO, EPI ARLES
Workshop ISM, 24/04/13

2. Outline
 The ARLES team
 Interoperability through dynamic synthesis
of mediators
 Some conclusions
2

3. Middleware for pervasive, distributed computing
System Architecture
The ARLES Team
 Software Architectures for Distributed Systems
• enabling the pervasive computing/ambient intelligence vision
3
d computing
QualityofService
Interoperability
CONNECT Project
Multi-radio
 Abstracting pervasive
networks and resources
 Leveraging highly dynamic
and heterogeneous
networking environments
System Models
Access and Interaction
Runtime Composition,
Reconfiguration, and Adaptation
Discovery
Multi-device Multi-platform

4. Facing the Interoperability Challenge
GMES: Global Monitoring for Environment & Security
Protocols for Discovery
4
, Interaction, Data exchange, Application, NFP
With heterogeneity along all dimensions
Highly-dynamic and complex environment

5. Facing the Interoperability Challenge
in the Mobile Environment
Mobile
Applica,on
??

6. Facing the Interoperability Challenge
in the Mobile Environment
Amiando to Regonline Mediator
SOAP/HTTPHTTP
EventFind() Login()
GetEvents()EventRead()

7. Looking for Babel fish…
Adapt protocol on the fly
using an intermediary system:
the mediator
Our Challenges:
Can we observe, synthesize and deploy
mediators dynamically?
Need for On-the-fly Interoperability
× Beyond SOTA
× Changing systems
× Standardization
× Common abstraction
➠ On-the-fly mediation
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8. 8
Emergent Middleware and Enablers

9. The CONNECT Process enabling
Emergent Middleware
9
DownloadPhoto
write PhotoFile
write PhotoMetadata
Behaviour learning Beh. learning
read PhotoFile
Mediator Model
downloadPhoto
read PhotoMetadata
Deployment
Monitor
Emergent
Middleware
Ontology-based semantics
DownloadPhoto = getPhoto
Photo = PhotoMetadata + PhotoFile
PhotoMetadata = PhotoID + Location + CameraID + details …
Synthesis
Deployment
write PhotoFile
write PhotoMetadata
DownloadPhoto
Discovery

10. 10
The CONNECTion Phase

11. Focus on Synthesis
11
 Interoperability through dynamic synthesis
of connectors
• Modeling
• Synthesis
• Deployment

12. Ontology-based
Networked System Model
 Ontology-based Functional Semantics
• Affordance
• The high-level functionality of a system
• e.g., <Req, PhotoSharing, Preferences, Photo>
• Interface
• A set of observable actions
• e.g., <SendSOAPRequest, DownloadPhoto,
{CameraID}, ∅>
 LTS-based Behavioural semantics
• The way the observable actions are coordinated
• At both application and middleware layers
• Application → Business logic
• Middleware → Communication & coordination protocol
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Interface
Networked
System
Affordance Behaviour
1
0..n
1
Ontologies
<SendSOAPRequest,
DownloadPhoto,{CameraID}, ∅>
<ReceiveSOAPResponse,
DownloadPhoto, ∅, {Photo}>

13. Emergent Middleware Synthesis
Informed by Ontologies
System (NS2)
Functional
MatchingSystem (NS1)
Ontologies
Does it make sense for NS1 and NS2
to interact?
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14. Functional Matching
14
System 2System1
AffC2 = <Req, PhotoSharing,
{CameraID}, {PhotoFile}>
AffDrone = <Prov, PhotoSharing,
∅, {Photo}>
What is the relation between a
PhotoFile and Photo ?

15. Domain-specific Ontology
15
PhotoSharingProducer PhotoSharingServer PhotoSharingConsumer
PhotoMetadata PhotoFile
Photo
SearchPhoto DownloadPhoto UploadPhoto
PhotoSharing
PhotoSharingProducer PhotoSharingServer PhotoSharingConsumer
PhotoMetadata PhotoFile
Photo
SearchPhoto DownloadPhoto UploadPhoto
PhotoSharing
Subsumption (is-a)
PhotoID: string
CameraID: string
Longitude: double
Latitude: double
Resolution: integer
Information:string
Attribute (PartOf)

16. Functional Matching
16
System 2System1
AffC2 = <Req, PhotoSharing,
{CameraID}, {PhotoFile}>
AffDrone = <Prov, PhotoSharing,
{CameraID}, {Photo}>
There is a functional matching between AffC2 and AffDrone
CameraID is subsumed by CameraID (contra-variant)
Photo is subsumed by PhotoFile (co-variant)

17. Emergent Middleware Synthesis
Informed by Ontologies
Middleware Abstraction Middleware Abstraction
System (NS2)
Functional
Matching
Yes
System (NS1)
Middleware-agnostic
Networked System (NS2)
Middleware-agnostic
System (NS1)
Ontologies
Abstract from the communication
protocol details and concentrate on
application semantics
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18. Middleware Ontology
18
RemoteProcedureCallAPI
MethodName Arguments ReturnValue
0..1 + follows {some} 0..1 + follows {some}
RemoteProcedureCallAPI
ReceveReply ReceiveCall Reply
MethodName Arguments ReturnValue
0..1 + follows {some}
+hasInput {some}
+hasOutput {some}
+hasOutput {some}
+hasInput {some}
+hasOutput {some}
Call
0..1 + follows {some}
+hasInput {some}
+hasInput {some}
Call
RemoteProcedureCallAPI
ReceveReply ReceiveCall Reply
MethodName Arguments ReturnValue
0..1 + follows {some}
+hasInput {some}
+hasOutput {some}
+hasOutput {some}
+hasInput {some}
+hasOutput {some}
SendSOAPRespReceiveSOAPResp ReceiveSOAPRqt
SOAPRequest SOAPResponse
SendSOAPRqt
Call
0..1 + follows {some}
+hasInput {some}
ReceiveReply ReceiveCall ReplyCall

19. Middleware Abstraction
19
<SendSOAPRequest,
DownloadPhoto, {CameraID}, ∅>
<ReceiveSOAPResponse,
DownloadPhoto, ∅, {Photo}>
<DownloadPhoto,{CameraID}, {Photo}>
C2 Behavior
C2 Middleware-agnostic
Behavior

20. Middleware Abstraction
20
Drone Behavior
Drone Middleware-agnostic
Behavior
<write, PhotoMetaData, ∅, {Photometadata}>
<write, PhotoFile, ∅, {Photofile}>
<PhotoMetaData, ∅, {Photometadata}>
<PhotoFile, ∅, {Photofile}>

21. Emergent Middleware Synthesis
Informed by Ontologies
Middleware Abstraction Middleware Abstraction
System (NS2)
Functional
Matching
Yes
System (NS1)
Middleware-agnostic
Networked System (NS2)
Middleware-agnostic
System (NS1)
Ontologies
21
Generate Mapping Processes
Mapping Processes
What are the translations that need to
be performed?

22. Generating Mapping Processes
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Drone InterfaceC2 Interface
<DownloadPhoto,{CameraID}, {Photo}> <PhotoMetaData, ∅, {Photometadata}>
<PhotoFile, ∅, {Photofile}>
DownloadPhotoPhotoMetaData PhotoFile
1 - Define the constraints that need to hold between compatible actions
2- Use constraint programming to find possible mapping between interfaces
<DownloadPhoto,{CameraID}, {Photo}>⟼
<<PhotoMetaData, ∅, {Photometadata}>, <PhotoFile, ∅, {Photofile}>>
e.g., Photo subsumes Photometadata union Photofile
3- Generate the corresponding mapping process

23. Emergent Middleware Synthesis
Informed by Ontologies
Middleware Abstraction Middleware Abstraction
Compatible
Partially compatible
Not compatible
Behavioral
Matching
System (NS2)
Functional
Matching
Yes
System (NS1)
Middleware-agnostic
Networked System (NS2)
Middleware-agnostic
System (NS1)
Ontologies
23
Generate Mapping Processes
Mapping Processes
Relies on ontology-based model
checking to verify the correctness of
the mapping processes

24. Behavioral Matching
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PhotoMetaData
PhotoFile
PhotoMetaData
PhotoFile
DownloadPhoto
DownloadPhoto
Drone BehaviorC2 Behavior Mediator Behavior

25. Emergent Middleware Synthesis
Informed by Ontologies
Middleware Abstraction Middleware Abstraction
CompatibleNot compatible
Behavioral
Matching
System (NS2)
Functional
Matching
Yes
System (NS1)
Middleware-agnostic
Networked System (NS2)
Middleware-agnostic
System (NS1)
Ontologies
25
Generate Mapping Processes
Mapping Processes
Deployment
Emergent
Middleware
Refines the mediator model into a
concrete software artifact:
an emergent middleware
Failure

26. Deployment
 Refine the mapping
processes using
middleware semantics
26
<receiveCall, DownloadPhoto,
{CameraID}, ∅>
<read, PhotoMetadata,
{cameraID}, {Photometadata}>
<reply, DownloadPhoto,
∅, {PhotoFile}>
<read, PhotoFile,
{PhotoID}, {PhotoFile}>
PhotoMetaData
PhotoFile
DownloadPhoto
Get PhotoID from PhotoMetadata
Middleware
& Domain-specific
Ontologies

27. Deployment (Cont’d)
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Composer 2
Parser 2
Parser 1
Composer1
Emergent Middleware
Mediator
System 2System1

28. Some Conclusions
 Interoperability remains a fundamental
problem in today’s complex distributed
systems
 Dynamic synthesis of mediators promises
to address interoperability in a future-proof
manner
 Ontologies have a key role to play in
supporting synthesis at both application
and middleware layers
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29. Some Conclusions (Cont’d)
 Ontologies
• Availability, characteristics, fuzziness
• Heterogeneity in ontologies, alignment
 Emergent middleware
• Learning, dependability, exception handling
• Evolution and incremental synthesis
 User in the loop
• The role of end users and experts in adaptation
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30. Thanks to colleagues:
Amel Bennaceur, Nikolaos Georgantas
Animesh Pathak & Ambientic contributors
Thank you

31. Further Information
ARLES: www.rocq.inria.fr/arles
CONNECT: connect-forever.eu
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