Pontis Interpretive MDD platform. May 2008

Transcription

1 Pontis Interpretive MDD platform May 2008

2 Agenda Background Model driven development Problems with main-stream approaches Product line structure Some facts The principles of our approach Detailed description Summary

3 Background Pontis Ltd. is a developer of online marketing automation solutions for the telecommunications market. Telecommunications software is characterized by Strict non-functional requirements Massive customization In order to address non-functional requirements we base the implementation on proven J2EE technologies In order to reduce TTM and cost of customization we decided to base our development on a model-driven, product-line technology

4 Model Driven Development Raise the level of abstraction Work outside the (Java) source/technical stuff Model is the source Model quality - We can use a model to describe an SUS (System Under Study). In this case, we consider the model correct if all its statements are true for the SUS. Ed Seidewitz, What Models Mean, IEEE SOFTWARE, September / O c t o b e r

5 Problems with existing practices Consistency - The consistency of the model is crucial in model centric approaches. An inconsistent model hinders downstream activities. Conformance - Conformance of the implementation model to design model is crucial for the model quality. When it is broken we can no longer be sure that designmodel statements are true in the System. Usability Different UI concept than programming IDEs, Change propagation and validation Expressiveness Limitations in UML profiles, other expressiveness capabilities Interoperability problems Generative No short route (Java-less) No short cycle Many languages Write code in an inappropriate environment Meta model changes require special activities from the user

6 Problems with existing practices Several areas need improvement: Detection of design flaws, omissions, and inconsistencies UML profiles support this work. UML 2.0 provides several facilities for defining such profiles but little support for checking them. More consistency between UML models and system requirements as well as implementations. Better mechanisms for traceability and round-trip engineering will help reduce these problems. In Practice : UML Software Architecture and Design Description Christian Lange, Eindhoven University of Technology, Michel Chaudron, Eindhoven University of Technology, Johan Muskens, Philips Research; IEEE Software 3/4/2006 page 40 "This implies that, to change the meta-model it is necessary to reprogram the tool an impractical option that does not allow users the flexibility to easily refine UML." "A Systematic Approach to Domain-Specific Language Design Using UML" B. Selic, isorc, pp. 2-9, 10th IEEE International Symposium on Object and Component-Oriented Real-Time Distributed Computing (ISORC'07), 2007

7 Product line structure Customer A Customer B Customer C Generic product Business-Application Framework Core language

8 Some facts Delivered >10 production systems during 2007 Telco-grade 50 TPS/CPU. Response time: 70 ms average, 250 ms 99% Customization time and effort dropped by an order of magnitude Generic product evolved in parallel Numbers Customization - ~150,000 LOC 82% of the source lines-of-code in customization projects are declarative (model classes and instances). The model contains : ~5500 classes more than 200 meta-classes tens of thousands of instances ~290,000 lines of code in model files (XML) Average Depth of Inheritance Tree (DIT) of model classes is ~99% of the application Java source code is governed by the model (i.e. the classes are defined in the model).

9 Principles of our approach Java IDE is proven to be efficient Java source Compiled Java Tools: Problems window Auto completion Navigation views Re-factor tools Java tooling Runtime platform (JVM, J2EE) Source code validation (compiler) Incremental validation few seconds Tooling Generic generation of runtime artifacts

10 Principles of our approach Java-like usability Model sources Model tooling Model Tools: Problems window Auto completion Navigation views Refactor tools Java source constrains Conformance validation Compiled model Compiled Java Java Tools: Problems window Auto completion Navigation views Refactor tools Java tooling Source code validation (compiler) Incremental validation few seconds Tooling Generic generation of runtime artifacts Java conformance validation Kernel Runtime platform (JVM, J2EE)

11 Principles of our approach Dependency injection Model sources Model Tools Model tooling Java source Java Tools Compiled model Compiled Java Java tooling Model contains object graphs. The kernel instantiates the object graphs Not all model changes require change in Java Hence the short route (Java-less) Kernel Runtime platform (JVM, J2EE)

12 Principles of our approach Metaclass extensibility Meta-class - a class whose instances are classes as well. A programming language that support meta-class extensibility is classified as Classbased object-oriented programming language : Smalltalk MetaclassTalk IBM s SOM (System Object Model). Lisp. Python. Ruby. Web Ontologies (OWL/Full) Mainstream OO languages do not support meta-class extensibility. doclets, attributes, aspect frameworks, annotations are the modern alternatives. Metaclasses are deeper magic than 99% of users should ever worry about. If you wonder whether you need them, you don't (the people who actually need them know with certainty that they need them, and don't need an explanation about why). Python Guru Tim Peters

13 Principles of our approach Metaclass extensibility Instance-of Instance-of Language MetaClass Language MetaClass Java.lang.Class Instance-of Sub-class of Instance-of Sub-class of Instance-of Developer defined MetaClass PersistentClass tablename String Developer defined class Instance-of Developer defined class Instance-of Instance-of Instance-of Customer tablename= CUSTOMER Instance-of Instance Instance Customer123 This provides another managed meta-data layer. This allows managed adaptation in class level behavior.

14 Principles of our approach Pure object oriented Objects Classes Customer123 Customer Class Meta-Classes PersistentClass MetaClass Method Field

15 Principles of our approach Metaclass extensibility Meta-class extensibility allows to define sets of sets that are subset of the set of all sets Can be stored in DB Can be queried Transactional Has name Has fields Has methods Has security key PersistentClass MetaClass Customer SecuredClass UI form StronglySecuredClass Order Catalog item BigCustomer Pricing service Movie Has 128 bit security key Typically, a class belongs to several classes. This is known as the multiple-inheritance problem.

16 Metaclass extensibility Multiple inheritance/cross cutting aspects Explicit meta-classes Meta class properties are used to define aspects Aspect definitions constraint the classes to have the right aspect glued Polymorphic and Interception aspects We base our approach on Explicit meta-class: Programming with Explicit Metaclasses in Smalltalk-80, Jean-Pierre Briot and Pierre Cointe Traits: Uniform and Safe Metaclass Composition St ephane Ducasse a Nathanael Sch arli a Roel Wuyts

17 Demo dependency injection with Spring framework Example taken from - Language support for Adaptive Object-Models using Metaclasses, Reza Razavi, Noury Bouraqadi,Joseph Yoder, Jean-Fran cois Perrot, Ralph Johnson

18 Demo Model driven dependency injection

19 Demo Domain Specific Modeling Language

20 Demo Domain Specific Modeling Language

21 Demo Meta-class extensibility

22 Demo Meta-class extensibility

23 Summary Interpretive approach Dependency injection Executable model -the model is the source, java-less change processes The Java implementation is the interpreter of the model classes and instances (behavior) Consistency and conformance Formal modeling Generic object oriented well formedness rules Generic mapping rules Model compiler verifies Java conformance

24 Summary Java-like usability Compiler Incremental compilation Break and correct Problems window Auto-completion Views and navigation tools Re-factor tools Expressiveness Meta-class extensibility. Aspects modeling. Enhanced modeling capabilities Continuous model

25 Summary Currently working on runtime adaptivity The compiler is part of the runtime core allowing for runtime changes of the model by end users The business-application framework component are reflective, hence runtime changes of the model are production ready (e.g. web-services, persistency)