Distributed Components, Model Driven Engineering & Specification Formalisms

1. Distributed Components,Model Driven Engineering & Specification Formalisms Eric Madelaine eric.madelaine@sophia.inria.fr INRIA Sophia-Antipolis Oasis team Mastere Ubinet -- UNS -- oct. 2010

2. Goals of the Course Understand the place of formal methods in the software design cycle Have a glimpse at a variety of modeling aspects Learn about component-based software architecture Explore one example of a component modeling tool Mastere Ubinet -- UNS -- oct. 2010

3. AGENDA Vocabulary specification, modeling, testing, verification…: Formal methods in the design flow of distributed/embedded systems Graphical Modeling Languages a zoo of UML diagrams Components models : Fractal, GCM Tool for component-based software modeling Vercors Component Environment Mastere Ubinet -- UNS -- oct. 2010

4. Formal methods Formal methods : Provide mathematical semantics to models so that their relation to implemented product can be asserted and proved : specification formalisms, (temporal) logics model checking, equivalence checking certification, testing model-based test generation Modeling languages: UML and variants (StateCharts, SysML,…) Dedicated IDLs and ADLs for system decomposition (…) Assertion languages (annotations) Mastere Ubinet -- UNS -- oct. 2010

5. Systems: structure and behavior In general, a system is: • constituted of components, interacting in a collaborative or hierarchical fashion (structure) • evolving, as a result of the composed functional of its components (behavior) a system changes state through time; time is counted in number of actions/operations • In highly dynamic systems the division is blurred, as structure is transformed by behaviors; e.g. in large scale software services (= business grids, SOA, …) • rarely the case in embedded systems See UML and elsewhere, models divided between structural and behavioral ones Mastere Ubinet -- UNS -- oct. 2010

6. Sign-off Requirements capture Component design / programming Component testing libraries Design Cycle Global testing (Initial) specification Architectural division Integration IP component reuse Implementation Mastere Ubinet -- UNS -- oct. 2010

7. Proof of requirements Sign-off Requirements capture Test generation Component testing Synthesis libraries Black box specification Correct-by-ConstructionImplementation Design cycle Early specification of Architecture and Interaction Global testing (Initial) specification Correct composition: interface compatibility, deadlock freeness, spec implementation Architectural division Integration IP component reuse Mastere Ubinet -- UNS -- oct. 2010

8. AGENDA Vocabulary specification, modeling, testing, verification…: Formal methods in the design flow of distributed/embedded systems Graphical Modeling Languages a zoo of UML diagrams Components models : Fractal, GCM Tool for component-based software modeling Vercors Component Environment Mastere Ubinet -- UNS -- oct. 2010

9. UML -- MDE -- Visual modelsSingle (unified) language “Too many different languages, platforms, formalisms….” • Unified visual Language • Everybody must speak the same language • Language for specification / code generation • Supposedly precise and non-ambiguous One single view is not enough: • Class diagrams • Sequence diagrams • Activity diagrams • State machines • Composite structure diagrams • Deployment diagrams • Marte profile Mastere Ubinet -- UNS -- oct. 2010

10. A single model is not enough! • Create several independent models but with common points and relations. Logical view Implementation view Analysts Developers Structure Software management Use-Case View Final userl Fonctionalité Deployment view Process View System Engineers System integrators Topologie du système, livraison, installation, communication Performance, scalabilité, débit Mastere Ubinet -- UNS -- oct. 2010

11. Class diagrams Mastere Ubinet -- UNS -- oct. 2010

12. ref Choose courses Sequence diagram Actor Objects :Registration Form :Registration Assistant :Course Manager : Student : Courses list 1: Build planning( ) 2: Get courses list( ) 3: Get courses list(Semester) 4: Get courses list ( ) Execution occurrence Messages 5: Display courses list ( ) Actor instance 6: Display empty EDT ( ) Interaction occurrence Mastere Ubinet -- UNS -- oct. 2010

13. Check Check planning Pre-requisite Assign Solve Course Update planning Activity diagram Choice Action Select course Concurrent executions [ Del course ] Del course [ Add course ] Synchronisation (Fork) Guard Synchronisation (Join) [ OK ] KO Transition conflicts Mastere Ubinet -- UNS -- oct. 2010

14. H H State machine diagram hired MCF success Candidate HDR Prof class 2 fail promotion Prof class 1 retirement back detached Engineer R&D Mastere Ubinet -- UNS -- oct. 2010

15. Component andComposite structure diagrams Provided / required interfaces Hierarchical components Ports Bindings Mastere Ubinet -- UNS -- oct. 2010

16. Deployment diagram <<client workstation>> PC JDK 1.6 0..2000 <<Campus LAN>> 1 <<application server>> deptinfo 1 Matlab Simulateur VHDL Eclipse 1 <<Campus LAN>> <<Campus LAN>> 1 1 <<legacy>> <<legacy RDBMS>> Apogée Geisha Mastere Ubinet -- UNS -- oct. 2010

17. MARTE: UML Profile forModeling and Analysis of Real-Time and Embedded Systems Mastere Ubinet -- UNS -- oct. 2010

18. UML pro/cons • Widely accepted, in teaching and in software industry: most computer scientists • Many proprietary or public-domain tools: modeling, meta-modeling, model transformation, code generation, … • No precise semantics (specific profiles may give a semantics) • Opposed to DSL (Domain Specific Languages)… small is beautiful ? Mastere Ubinet -- UNS -- oct. 2010

19. AGENDA Vocabulary specification, modeling, testing, verification…: Formal methods in the design flow of distributed/embedded systems Graphical Modeling Languages a zoo of UML diagrams Components models : Fractal, GCM Tool for component-based software modeling Vercors Component Environment Mastere Ubinet -- UNS -- oct. 2010

20. Components • Hardware / software • Synchronous / Asynchronous • Flat / Hierarchical Mastere Ubinet -- UNS -- oct. 2010

21. The Fractal project • Reflective software component model technology for the construction of highly adaptable, and reconfigurable distributed systems • A programming-language independent component model • A set of tools to support programming and assembling • Software industries needs (≠ object-orientation): Dependencies, assembly, packaging, deployment, configuration • Open and adaptable/extensible • Component [Szyperski, 2002]: “A component is a unit of composition with contractually specified interfaces and context dependencies only. A software component can be deployed independently and is subject to composition by third parties.” Mastere Ubinet -- UNS -- oct. 2010

22. The Fractalcomponent model • Systems and middleware engineering • Generic enough to be applied to any other domain • Fine grain (opposed to EJB or CCM), close to a class model • Lightweight (low overhead on top of objects) • Independent from programming languages • Homogeneous vision of all layers (OS, middleware, services, applications) • Usable as a component framework to build applications • with “standard” Fractal components • Usable as a component framework framework • building different kinds of components • with minimum introspection and simple aggregation (à la COM) • with binding and lifecycle controllers (à la OSGi) • with a two-level hierarchy and bindings (à la SCA) • with persistence and transaction controllers (à la EJB) • with attribute controllers (à la MBean) Mastere Ubinet -- UNS -- oct. 2010

23. Interfaces Component Required Provided Binding Fractal Mastere Ubinet -- UNS -- oct. 2010

24. Fractal : controllers • Control • Non functional (technical) properties • Implemented in the membrane • Made of a set of controllers • E.g. security, transaction, persistence, start/stop, naming, autonomicity • Controllers accessible through a control interface • Controllers and membranes are open Mastere Ubinet -- UNS -- oct. 2010

25. Fractal tools • Fraclet • programming model based on annotations (within Java programs) • Fractal ADL • XML-based architecture description language (ADL) • Fractal API • set of Java interfaces for • introspection • reconfiguration • dynamic creation/modification of Fractal components and component assemblies Mastere Ubinet -- UNS -- oct. 2010

26. Fractal : development tools F4E: Eclipse development environment for Fractal applications Mastere Ubinet -- UNS -- oct. 2010

27. GCMGrid Component Model A Fractal Extension Scopes and Objectives: Grid/Cloud Codes that Compose and Deploy No programming, No Scripting, … Innovations: Abstract Deployment Multicast and GatherCast Controller (NF) Components Standardization By the ETSI TC-GRID (2008-2010) Mastere Ubinet -- UNS -- oct. 2010

28. GCM: asynchronous model Distributed components : • No shared memory • Communication = Remote Method Call • Physical infrastructure ≠ logical (virtual) architecture • Asynchrony of computation : Remote Calls are non-blocking Notion of Future Objects. Mastere Ubinet -- UNS -- oct. 2010

29. GCM: NxM communication • 1 to N = multicast / broadcast / scatter • N to 1 bindings = gathercast • Attach a behaviour (policy) to these interfaces Mastere Ubinet -- UNS -- oct. 2010

30. GCM: components for controllers “Componentize” the membrane: • Build controllers in a structured way • Reuse of controller components • Applications: control components for self-optimization, self-healing, self-configuring, interceptors for encryption, authentication, … Mastere Ubinet -- UNS -- oct. 2010

31. GCM architecture specifications: VCE tool Mastere Ubinet -- UNS -- oct. 2010

32. Component models: Java Beans, EJBeans, Mbeans, Microsoft COM & .Net, OSGI bundles, UML 2.0 Components, Service Component Architecture (SCA), Common Component Architecture (CCA), etc. ADLs: Wright, Acme, Rapide, Unicon, C2, Darwin, Room, xArch, ComUnity, OpenCOM, Olan, etc. Programming languages: ArchJava, Jiazzi, ComponentJ, Piccola, Scala, etc. Fractal is a component model: ◮ Programming-language independent: Many different implementations ◮ Reflective: Components can provide introspection capabilities ◮ Open: No predefined semantics for connection, composition and reflection With extensible architecture description language (ADL): ◮ Core ADL for basic concepts ◮ Additional ADL modules for different architectures CBSE approaches, Fractal and GCM GCMis a compliant extension to Fractal with : • A specific asynchronous semantics for connection • Specific communication constructs for collective interfaces ◮ A Java middleware implementation Mastere Ubinet -- UNS -- oct. 2010

33. AGENDA Vocabulary specification, modeling, testing, verification…: Formal methods in the design flow of distributed/embedded systems Graphical Modeling Languages a zoo of UML diagrams Components models : Fractal, GCM Tool for component-based software modeling Vercors Component Environment Mastere Ubinet -- UNS -- oct. 2010

34. VCEVerCors Component Editor A “Domain Specific Language” for Fractal/GCM • Component architecture diagrams • Behaviour diagrams • Model generation for verification tools • Code generation Agenda: • Tool architecture • Validation rules • “hands-on” exercices Mastere Ubinet -- UNS -- oct. 2010

35. VCEArchitecture Vercors Graphical Editor (Eclipse Plugin) G C M / ProActive ADL/IDL (final) Runtime Behav Specification (LTS) pNets/ Fiacre Model Generator Finite model Prover Mastere Ubinet -- UNS -- oct. 2010

36. JDC Formula VCE Architecture(middle term) Vercors G C M / ProActive ADL/IDL (final) Graphical Editor (Eclipse Plugin) Code Generator Java Skeletons JDC Specification Runtime Business code pNets/ Fiacre Model Generator Finite model Prover Formula Compiler Mastere Ubinet -- UNS -- oct. 2010

37. VCEEclipse and MDE Tools Eclipse Modeling Tools: • EMF (Eclipse Modeling Framework): XMI model definition and Java code generation • GEF (Graphical Editing Framework) • GMF (Graphical Modeling Framework) for developing graphical editors • Model Development Tools • Atlas Transformation Language (ATL) • …. Mastere Ubinet -- UNS -- oct. 2010

38. Mastere Ubinet -- UNS -- oct. 2010

39. VCEValidation, OCL Several notions of correctness in the diagram editors: • Geometric/Structural correctness, by construction: the graphical tools maintain a number of constraints, like bindings attached to interfaces, interfaces on the box borders, etc. • Static Semantics: some rules are related to the model structure, not to the graphical objects. E.g. bindings should not cross component levels, or sibling objects should have distinct names… • There is a “Validation” function (and button), that must be checked only on “finished” diagrams, before model/code generation. It is defined using OCL rules. Mastere Ubinet -- UNS -- oct. 2010

40. VCE : Validation, OCL OCL example : context Binding inv FromClientToServer_InContent_ROLES: ( Content.allInstances()->exists(c : Content | c.bindings->includes(self)) and Content.allInstances()->any(bindings->includes(self)).subcomponents ->exists(sc : Component | sc.oclAsType(ComponentDefinition).externalInterfaces ->includes(self.sourceInterface)) and Content.allInstances()->any(bindings->includes(self)).subcomponents ->exists(sc : Component | sc.oclAsType(ComponentDefinition).externalInterfaces ->includes(self.targetInterface)) ) implies self.sourceInterface.role = InterfaceRole::client and self.targetInterface.role = InterfaceRole::server Mastere Ubinet -- UNS -- oct. 2010

41. Conclusion • Modeling formalisms: capture various aspects of software design process 2) Component frameworks: provide method, tools, middleware for programming large-scale applications • Vercors: an example of a modeling framework for component-based applications http://www-sop.inria.fr/oasis/Vercors There will be at least one studentship proposal in the context of the Vercors plateform. Mastere Ubinet -- UNS -- oct. 2010

42. More References • Fractal: • http://fractal.objectweb.org/doc/ecoop06/Fractal-ECOOP2006-Tutorial.pdf • http://fractal.objectweb.org/tutorials/fractal • (in french) : http://www-sop.inria.fr/members/Eric.Madelaine/Teaching/Ubinet2010/FractalSeinturier2008.pdf • GCM: • http://www-sop.inria.fr/members/Eric.Madelaine/Teaching/Ubinet2010/2006-GCM-GridsWork.ppt • F. Baude, D. Caromel, C. Dalmasso, M. Danelutto, V. Getov, L. Henrio, C. Perez: GCM: A Grid Extension to Fractal for Autonomous Distributed Components, in Annals of Telecommunications, Vol. 64, no1, jan 2009. • Vercors: • http://www-sop.inria.fr/oasis/Vercors (papers, download, case-studies) Mastere Ubinet -- UNS -- oct. 2010

43. Bonus • Service-oriented architectures • Components versus Services • VCE examples and exercices Mastere Ubinet -- UNS -- oct. 2010

44. What is a Service? • Standardized interface • Self-contained with no dependencies to other services • available • Little integration need • Coarse-grained • Context-independent • Services themselves have context • Allows for Service Composition • Quality of Service(QoS)Attributes which can be measured Mastere Ubinet -- UNS -- oct. 2010

45. Components vs. Services1 • Services • Loose coupling • Message exchanges • Policy • Peer-to-peer • Composable • Context independent • Some overhead • Medium to coarse granularity • Components • Tight coupling • Client requires library • Client / Server • Extendable • Stateless • Fast • Small to medium granularity 1) From Prof. Schahram Dustdar, S-Cube virtual campus Mastere Ubinet -- UNS -- oct. 2010

46. VCEExamples for the SSDE courseHands-on, Vercors environment • Component: example, external view • Component: exercise, internal architecture • Multicast: example, workflow style • Multicast: exercise, build a matrix application • Master/slave, example, RPC style • Matrix: example, parameterized style • Diagram correctness: exercise Mastere Ubinet -- UNS -- oct. 2010

47. External view Mastere Ubinet -- UNS -- oct. 2010

48. Internal architecture(exercise) Build a composite component, with : • Outside: • 1 serveur interface SI • 2 client interface CI1, CI2 • A number of control (NF) interfaces • Inside: • 2 subcomponents • One connected to SI • Each connected to one client interface • One binding between them Check its validity and produce the ADL Mastere Ubinet -- UNS -- oct. 2010

49. Multicast and gathercast, workflow style Mastere Ubinet -- UNS -- oct. 2010

50. Composite, multicast, matrix(travail à faire en cours) Build a composite component, with: • One server interface, with an internal multicast interface • 2 x 3 subcomponents representing matrix blocks, each linked to its left neighbour Mastere Ubinet -- UNS -- oct. 2010