dynamic synthesis of mediators in ubiquitous environments

Dynamic Synthesis of Mediators in Ubiquitous Environments

Amel Bennaceur

UPMC PhD Defense

work performed within the ARLES project-team

supervised by Valérie Issarny

Dynamic Synthesis of Mediators

18 July 20132

The Need for Dynamic Synthesis of Mediators

Same functionality, various applications• Heterogeneous Interfaces

How to represent files?

What kind of actions can be performed on these files?


18 July 20133


Same functionality, various applications• Heterogeneous Interfaces & Behaviours What is the order in which these

actions must be performed?


18 July 20134



Diversity of middleware solutions& Behaviours

What is the interaction protocol?

What is the message format?

HTTP/XML

SOAP/XML

REST/JSON

FTP/XML

REST/XML


18 July 20135


FTP/XML


Diversity of middleware solutions Ubiquity

& Behaviours


18 July 20136


FTP/XML



& Behaviours

Mediator

Mediator

Mediator

Mediator


18 July 20137


Mediator



& Behaviours


18 July 20138

Thesis Statement

Components with compatible functionalities should be able to interact despite

heterogeneities in their interfaces and behaviorsat both application and middleware layers.

Mediators that seamlessly overcome these heterogeneities should be dynamically

synthesised and deployed in their environment.


18 July 20139

Dynamic Synthesis of Mediators Informed by Ontologies

Model Extraction

Model Extraction

Synthesis


18 July 201310

Modelling Components

Background from Semantic Web Services Ontology-based functional semantics

• Capability• The high-level functionality of a system

• Interface• A set of observable actions

LTS-based behavioural semantics• The way the observable actions are

coordinated


18 July 201311

Modelling Components

Background from Semantic Web Services Ontology-based functional semantics

• Capability• The high-level functionality of a system

• Interface• A set of observable actions

LTS-based behavioural semantics• The way the observable actions are

coordinated• At both application and middleware layers

• Application → Business logic• Middleware → Communication

& coordination protocol


18 July 201312

The Steps for Dynamic Synthesis of Mediators

Interface Matching

Generating Correct-by-Construction Mediators

Concretisation

Components’ interfaces

Components’ behaviours

Components’ communication protocols

Overcoming the Heterogeneity of

Application layer

Middlewarelayer

many-to-many

under ambiguity

different interaction paradigms

unified approach


18 July 201313

Interface Matching - Example

~

~ ~

~

Interface Matching

Generating Mediators

Concretisation


18 July 201314

Definition of Interface Matching

Matching interface to interface consists in finding all pairs of actions such that a sequence of actions required by the former can be safely performed using a sequence of actions provided by the latter. In addition, all pairs are minimal.

But… interface matching computation is NP-Complete

Interface Matching


Concretisation


18 July 201315

Interface Matching usingConstraint Programming

Interface Matching


Concretisation


18 July 201316

Interface Matching using CP

Constraints: safety properties for

and

Interface Matching


Concretisation

The functionality offered by the provided actions covers that of the required actions

Each required action has its output data available (also in the appropriate format) at the time of execution, and

Each provided action has its input data available at the time of execution.


18 July 201317

Interface Matching usingConstraint Programming

Interface Matching


Concretisation


18 July 201318

Ontology Encoding

But… No CP solver for ontological subsumption

Define a bit vector encoding of the ontology which is correct and complete regarding the subsumption and disjunction axioms.

Interface Matching


Concretisation


18 July 201319

Ontology Encoding - ExampleInterface Matching


Concretisation


18 July 201320

From Interface Matching to Matching Process

such that

… …

Associate a matching process

…

… … …

Interface Matching


Concretisation


18 July 201321


Interface Matching


Concretisation





Application layer

Middlewarelayer

many-to-many

under ambiguity


unified approach


18 July 201322

Mediator Synthesis - ExampleWebDAV Client Google Docs Service Matching Processes

Mediator

Interface Matching


Concretisation


18 July 201323


The mediator composes the mapping processes in order to allow both components, whose behaviours are

and , to coordinate and reach their final states The basic case Translation

Interface Matching


Concretisation


18 July 201324


Interface Matching


Concretisation


18 July 201325

Mediator Synthesis


and , to coordinate and reach their final states The basic case Translation

Interface Matching


Concretisation


18 July 201326

Mediator Synthesis


and , to coordinate and reach their final states Consumption of extra provided actions

Interface Matching


Concretisation


18 July 201327

Mediator Synthesis


and , to coordinate and reach their final states Consumption of extra provided actions

Interface Matching


Concretisation


18 July 201328


Interface Matching


Concretisation





Application layer

Middlewarelayer

many-to-many

under ambiguity


unified approach


18 July 201329

From Abstract to Concrete Mediator

Refine the synthesised mediator • Translating application data

• Combining ontology relations with schema matching techniques

• Coordinating middleware protocols• Deploying the mediator

Interface Matching


Concretisation


18 July 201330

Data Translations

<entry xmlns:gd="http://schemas.google.com/g/2005" gd:etag="'HhJSFgpeRyt7ImBq'">

<ref>https://docs.google.com/feeds/id/pdf%3AtestPdf</ref> <published>2012-04-09T18:23:09.035Z</published> <updated>2012-04-09T18:273:09.035Z</updated> <app:edited xmlns:app="http://www.w3.org/2007/app"> 2009-06-18T22:16:02.388Z </app:edited> <title>PDF's Title</title> <content type="application/pdf" src="https://doc-04-20-docs.googleusercontent.com/docs/ secure/m71240...U1?h=1630126&e=download&gd=true"/> <link rel="alternate" type="text/html" href="https://docs.google.com/ fileview? id=testPdf&hl=en"/> <author> <name>benamel</name> <email>[email protected]</email> </author> <gd:resourceId>pdf:testPdf</gd:resourceId> <gd:lastViewed>2012-06-18T22:16:02.384Z </gd:lastViewed> <docs:writersCanInvite value="false"/> <docs:md5Checksum>2b01142f7481c7b056c4b410d28f33cf </docs:md5Checksum> </entry>

<w:response> <w:href>https://docs.google.com/feeds/id/pdf%3AtestPdf</w:href> <w:propstat> <w:status>HTTP/1.1 200 OK</w:status> <w:prop> <w:displayname>testPdf.pdf</w:displayname> <w:author>benamel</w:author> </w:prop> </w:propstat></w:response>

0.5

0.2

0.6

0.2

WebDAV File

Google Docs Document

Interface Matching


Concretisation


18 July 201331

Data Translations

Combine ontology relations with schema matching techniques• Subsumption: Use schema matching tools to find, for each simple data concept in the target, a corresponding data concept in the source

• Disjunction:

Select the appropriate translation function

such that

• Aggregation:

Use schema matching tools to find, for each simple data concept in the target, a corresponding data concept in the concatenation of source schemas


18 July 201332

Coordinating middleware Protocols- Example

ReceiveRequest[MoveFile][SourceURI,DestinationURI]

SendRequest [DownloadDocument][SourceURI]

SendReply[MoveFile][Acknowledgment]

ReceiveResponse [DownloadDocument][Document]

Concretise

DownloadDocument

UploadDocument

MoveFile

Compute Metadata and Content from DocumentDeleteDocument

SendRequest [UploadDocument][Metadata, Content, DestinationURI]

…

Interface Matching


Concretisation

Compute SourceURI


18 July 201333

Interaction Patterns Interface Matching


Concretisation


18 July 201334

Deploying the Mediator

Mediator

Interface Matching


Concretisation


18 July 2013

Assessment


18 July 201336

Mediator Performance -File Management

There is an overhead but response time for a request < 1s

WebDAV/WebDAV GDocs/GDocs WebDAV/GDocs Gdocs/WebDAV0

200

400

600

800

1000

1200

1400

1600

1800

Tim

e t

o p

erf

orm

an

inte

rac

tio

n (

ms

)


18 July 201337

Applicability - Case Studies

×

×one-to-one interface matching

one-to-many interface matching

×

×××


cross interaction patterns

mediation at runtime


cross middleware solutions

Instant Messaging

File Management

Event Management

Emergency Management


18 July 201338

Processing Time per Mediation Step

Depends on the size of the ontology Depends on the type of mismatches Negligible for real-world cases


18 July 201339

Conclusion - Contributions

Generating interface matching automatically• Further dealing with one-to-many and many-to-many

correspondence

Synthesising correct-by-construction mediators• Further dealing with ambiguity of interface matching

Dealing with differences at both application and middleware layer

Dynamic Mediator Synthesis:

From Theory to Practice


18 July 201340

Conclusion -The Big Picture

CONNECT Enablers


18 July 201341

Towards the Next Generation of Software

First Generation• Execution

Second Generation• Learning

Next Generation• Innovation


18 July 2013

Thank you


18 July 201343

Further Information

Home page: amel.me ARLES: www.rocq.inria.fr/arles CONNECT: connect-forever.eu

Automated Mediator Synthesis: Combining Behavioural and Ontological Reasoning, In Proc. SEFM 2013

The Role of [email protected] in Supporting On-the-fly Interoperability, Springer Computing 2013

Composing Distributed Systems: Overcoming the Interoperability Challenge, FMCO 2012

The Role of Ontologies in Emergent Middleware: Supporting Interoperability in Complex Distributed Systems, In Proc. Middleware 2011

Middleware-layer Connector Synthesis: Beyond State of the Art in Middleware Interoperability, In SFM 2011

…

dynamic synthesis of mediators in ubiquitous environments

Technology