Model Driven Engineering

Transcription

1 Model Driven Engineering... and there's the code Monique Snoeck Gewoon Hoogleraar KULeuven, Fac. Economie en Bedrijfswetenschappen Beleidsinformatica 1 (c) Monique Snoeck Agenda Basic Concepts behind MDA work Prototyping MERODE Enterprise models Event-based Distributed Processes (Pieter Hens) Service Coordination (Geert Monsieur) Lessons learned (c) Monique Snoeck 25/04/

2 Software Development Life Cycle: Current Practice Requirements Mostly Text Diagrams & Text Analysis Design Diagrams & Text Informal Formal Test (c) Monique Snoeck 25/04/ Unraveling the "Hocus Pocus" of going from specs to design (c) Monique Snoeck 25/04/

3 Software Development Life Cycle: MDA Practice Requirements Mostly Text Analysis PIM al Steps Design PSM Informal Formal Test (c) Monique Snoeck 25/04/ Problems with current practices Productivity code is the driving force Maintenance and documentation time consuming task benefit is for others code is the documentation but high level documentation absolute must for complex systems Portability frequent new techologies adopted because demanded, solve real problems, no support for older technologies Complexity worsened by different versions, lack of backward compatibility Interoperability Systems do not exist in isolation Individual Components use best technologies, but need to interact (c) Monique Snoeck 25/04/

4 Implementation by C B A Implementation Implementation for Implementation Environment for C Environment for B EnvironmentA Technology Technology requirements requirements Technology for Environment requirements for C Environment for B Environment A (c) Monique Snoeck 7 MDA Development Life Cycle PIM: Platform Independent Model describes the system from a business perspective PSM: Platform Specific Model Specifies the system in terms of constructs available in a specific implementation technology al approach PIM Tool PSM Tool (c) Monique Snoeck 25/04/

5 MDA Benefits Productivity reduce code & testing increase available design time Prototype faster detect requirements changes sooner shift of attention from code to PIM to solving the business problem BUT: development of transformations is hard! Documentation PIM fulfils the role of high-level documentation Tools needed for maintaining the relationships between PIM PSM and Still documentation required for PIM, e.g. motivation of choices (c) Monique Snoeck 25/04/ MDA Benefits Portability PIM is by definition completely portable effective portability depends on available transformations Interoperability PIM First First PSM PSM Bridge PSM Second Second Bridge (c) Monique Snoeck 25/04/

6 MDA Required building blocks Well-specified high-level models: precise and complete Languages to write these high-level models Definitions of how to transform a PIM into PSMs custom made or publicly available Definitions of how to transform a PSM into code Languages to write these transformations Tools to execute these PIM-PSM transformations with features to tune and debug transformations Tools to execute transformation of PSM to code (c) Monique Snoeck 25/04/ MDA Framework Modelling Languages Entity Relationship Modelling UML Class Diagram Finite State Machines Harel State charts Business Process Modelling Notation UML Activity Diagram BPEL Petri Nets Use Case Diagrams Languages XSLT AndroMDA language ATL... Tools XSLT execution AndroMDA Eclipse... (c) Monique Snoeck 25/04/

7 MDA Framework: Models Different views in one Language (Single Model, multiple views) e.g. UML Different Views/Models in different languages UML ER BPMN Written in Written in Describes Describes Describes Describes System System (c) Monique Snoeck 25/04/ Platform independence of models is key for achieving portability PIM versus PSM e.g. Interaction diagram: language independent platform independent? object oriented platform specific? Process-Data CRUD-Matrix language independent platform independent transforms to any technology platform independent Models are more or less platform independent/specific (c) Monique Snoeck 25/04/

8 MDA Framework: s PIM Definition Tool PSM Definition Tool A transformation is the automatic generation of a target model from a source model according to some transformation definition A transformation definition is a set of transformation rules definitions are between languages A transformation rule defines how one or more constructs in the source language can be transformed into one or more constructs in the target language (c) Monique Snoeck 25/04/ UML Class Diagram MDA Framework: s Customer ID : INTEGER Name: STRING > owns < owned_by Account Balance: real Deposit (amount:real) Withdraw (amount: real) UML Class D to Eiffel Eiffel Class Customer Owns: Linked_list (ACCOUNT) ID: INTEGER name: STRING End Class Account Owned_by: CUSTOMER balance: REAL Deposit (amount: real) is Withdraw (amount: real) is End UML Class D to SQL SQL DDL Create Table Customer ("ID" "integer", name char(50) ) Create Table Account ( Customer_id INTEGER, balance DOUBLE, ) (c) Monique Snoeck 25/04/

9 MDA way of working Elaboration Implementation independence Specify first Implementation by elaboration implementation bias creeps in too soon then transform Level of detail (c) Monique Snoeck 17 Pushing Best Practices below the line FLAT FILE DATABASE MGT SYSTEM Application Application Record insertion record deletion record search sorting indexing storage Record insertion record deletion record search sorting indexing storage 25/04/

10 Pushing Best Practices below the line Traditional MDA Specifications Specifications Object Interaction Pattern Other Architectural Pattern OO relational Storage Pattern Object Interaction Pattern Other Architectural Pattern OO relational Storage Pattern 25/04/ MDA Today: Tools PIM editors PIM to PSM transformation tools PSM to transformation tools PIM to transformation tools Tunable Tools Transf.Def. Editor Model Editor Tool File Generator Files Interchange of Models (in XMI, JMI or IDL) and Definitions Transf.Def. Repository Model Validator Model Repository File Parser Editor(IDE) (c) Monique Snoeck 25/04/

11 Agenda Basic Concepts behind MDA work Prototyping MERODE Enterprise models Event-based Distributed Processes (Pieter Hens) Service Coordination (Geert Monsieur) Lessons learned (c) Monique Snoeck 25/04/ MERODE prototyping (1) Model/Plan (2) (3) Working Application (1) Model/Plan (2) Transformatie Definition Tool 22 (c) Monique Snoeck (c) Monique Snoeck 11

12 MDA Framework: s PIM MERODE Definition Tool PSM UML/ XMI Definition Tool Java Merode EDG/OET EDG/OET to UML XSLT UML Class Diagram (XMI) UML/XMI Class Diagram Coll. D. to Java AndroMDA Java (c) Monique Snoeck 25/04/ Merode MXP to XMI via XSLT Object types, attributes, events, methods String: Naam String: Nr MXP: <mxp:el.object_type id="484" name="a" specialisation_total="false"> <mxp:description></mxp:description> <mxp:constraints></mxp:constraints> <mxp:multiplepropagationconstraints> </mxp:multiplepropagationconstraints> <mxp:has_attributes> <mxp:el.attribute id="485" name="naam" datatype="486"> <mxp:description></mxp:description> <mxp:validation_rule></mxp:validation_rule> <mxp:implementation></mxp:implementation> </mxp:el.attribute> <mxp:el.attribute id="487" name="nr" datatype="486"> <mxp:description></mxp:description> <mxp:validation_rule></mxp:validation_rule> <mxp:implementation></mxp:implementation> </mxp:el.attribute> </mxp:has_attributes> </mxp:el.object_type> MXP: <mxp:el.event id="488" name="cr_a" type="default"> <mxp:description></mxp:description> <mxp:has_attributes> </mxp:has_attributes> </mxp:el.event> <mxp:el.event id="489" name="end_a" type="default"> <mxp:description></mxp:description> <mxp:has_attributes> </mxp:has_attributes> </mxp:el.event> (c) Monique Snoeck 25/04/

13 Merode MXP to XMI via XSLT MXP: <mxp:el.method type="o/c" id="490" name="cr_a" computed="false" is_disabled="false" disabled="false" for_event="488" in_o_type="484"> <mxp:precondition></mxp:precondition> <mxp:postcondition></mxp:postcondition> <mxp:implementation></mxp:implementation> <mxp:has_attributes> </mxp:has_attributes> </mxp:el.method> <mxp:el.method type="o/e" id="491" name="end_a" computed="false" is_disabled="false" disabled="false" for_event="489" in_o_type="484"> <mxp:precondition></mxp:precondition> <mxp:postcondition></mxp:postcondition> <mxp:implementation></mxp:implementation> <mxp:has_attributes> </mxp:has_attributes> </mxp:el.method> (c) Monique Snoeck 25/04/ Merode MXP to XMI via XSLT XMI: <UML:Class visibility="public" isspecification="false" isroot="false" isleaf="false" isabstract="false" isactive="false" stereotype="sentity" xmi.id="484" name="a"> <UML:Classifier.feature> <UML:Attribute visibility="private" isspecification="false" ownerscope="instance" xmi.id="485" name="naam" type=" "/> <UML:Attribute visibility="private" isspecification="false" ownerscope="instance" xmi.id="487" name="nr" type=" "/> <UML:Operation visibility="public" isspecification="false" ownerscope="instance" isquery="false" concurrency="sequential" isroot="false" isleaf="false" isabstract="false" xmi.id="490" name="cr_a" stereotype="soc"> <UML:BehavioralFeature.parameter> <UML:Parameter kind="return" type="dvoid" xmi.id="mp490"/> </UML:BehavioralFeature.parameter> </UML:Operation> <UML:Operation visibility="public" isspecification="false" ownerscope="instance" isquery="false" concurrency="sequential" isroot="false" isleaf="false" isabstract="false" xmi.id="491" name="end_a" stereotype="soe"> <UML:BehavioralFeature.parameter> <UML:Parameter kind="return" type="dvoid" xmi.id="mp491"/> </UML:BehavioralFeature.parameter> </UML:Operation> </UML:Classifier.feature> </UML:Class> (c) Monique Snoeck 25/04/

14 XMI to Java- (AndroMDA) rule for methods: #foreach ( $op in $class.getuniquemethods())... #if ($op.endingmethod) if(haslivingdependents()) throw new MerodeException ("Precondition violation in ending method \"${opname}\" in class ${class.name}:\nobject has living dependents");... (c) Monique Snoeck 25/04/ XMI to Java (AndroMDA) AImpl.java package org.merode.application; public class AImpl extends A { // constructor public AImpl() { } // concrete business methods that were declared // abstract in class A... public voidcr_a(java.lang.stringnaam, java.lang.stringnr) { MerodeLogger.logln("ExecutingA.cr_a (O/C)"); setnaam (naam); setnr (nr); } public voidend_a() { MerodeLogger.logln("ExecutingA.end_a (O/E)"); } public voidcheck_cr_a() throws MerodeException { MerodeLogger.log("Checking A.cr_a..."); MerodeLogger.logln("passed"); } public voidcheck_end_a() throws MerodeException { MerodeLogger.log("Checking A.end_a..."); if(haslivingdependents()) throw new MerodeException ("Preconditionviolation in ending method \"end_a\" in class A:\nObject has living dependents"); MerodeLogger.logln("passed"); } private boolean haslivingdependents() { return false; } } (c) Monique Snoeck 25/04/

15 to Prototype PIM: Enterprise Model in Mermaid Object Types, Event Types, Methods Generate Persistence layer Generate Event Handling Layer Generate Default Input and Output Services one input service per event type two output services per object type view all instances in class view 1 object Generate Default GUI main Menu: list of all object type per object type: list of all owned event types view all instances in class view related instances (c) Monique Snoeck 25/04/ : Persistence Layer Object Type Abstract Class Implementation Class Factory 1 method per event type the object type participates in + 1 method for checking the corresponding preconditions Attribute of Object Type Attribute in Implementation Class Association Object Type participates in Association Attribute in Implementation Class (c) Monique Snoeck 25/04/

16 : Persistence Layer Abstract state class (associated with mapped class) Object Type's FSM For each State of the FSM, a State subclass of the mapped Abstract state class Per mapped State subclass, methods for checking state conditions for each event in of the mapped Abstract state class (c) Monique Snoeck 25/04/ : Event Layer (c) Monique Snoeck 25/04/

17 GUI layer Main Window Domain Object Window Event Window (c) Monique Snoeck 25/04/ PhD Pieter Hens Event-based Distributed Business Processes 34 (c) Monique Snoeck 25/04/2011 (c) Monique Snoeck 17

18 Case: Using MDA to improve load balancing in business process execution Model2Model transformation to split a global process into multiple smaller lightweight- processes Business Process Modeler Decentralization Algorithm BPMN Model PIM Split BPMN Split Split BPMN Model BPMN Model Model PSM PSM PSM Deploy and distribute Process Process Engine Process Engine Engine (c) Monique Snoeck 25/04/ PIM2PSM (1) Each task in the original process becomes a process on its own For each new process, start rules are calculated A start rules depicts when a split process can start its execution The split processes are also in BPMNnotation The start rules are transcribed with the use of bpmn-start-events (c) Monique Snoeck 25/04/

19 PIM2PSM (2) Realized with the Atlas Language Declarative language to define transformation rules from objects in the source meta-model to objects in the target meta-model Available as an Eclipse Plugin Conforms to Ecore MetaMetaModel BPMN2.0 Conforms to Source Model Conforms to ATL Conforms to BPMN2EventBPMN BPMN2.0 Conforms to Target Model (c) Monique Snoeck 25/04/ ATL Input = Original Business Process model (BPMN2.0-XML- File) ATL Output = Split Business Processes (BPMN2.0-XML- File) <definitions> <process id="pizzacompany"> <startevent id="orderreceived" name=""> [ ] </startevent> <task completionquantity="1" id="packageorder" isforcompensation="false" name="packageorder" startquantity="1"> [ ] </task> <parallelgateway gatewaydirection="converging" id="sid- Gateway1" name=""> [ ] </parallelgateway> <task completionquantity="1" id="arrangepayment" isforcompensation="false" name="arangepayment" startquantity="1"> [ ] </task> <parallelgateway gatewaydirection="converging" id="sid- Gateway2" name=""> [ ] </parallelgateway> [ ] </process> </definitions> PIM2PSM (3) ATL Script Split Process <definitions> <process id="sid-processpackageorder"> <startevent id="starteventpackageorder6"> <outgoing>sfinputpackageorder8</outgoing> <signaleventdefinition id="inputdefsid-signalbakepizza" signalref="signalbakepizza" /> </startevent> <startevent id="starteventpackageorder10" parallelmultiple="true"> <outgoing>sfinputpackageorder12</outgoing> <signaleventdefinition id="inputdefsid-signalcreatesidedish" signalref="signalcreatesidedish" /> <signaleventdefinition id="inputdefsid-signalbakepizza" signalref="signalbakepizza" /> </startevent> <sequenceflow id="sfinputpackageorder8" targetref="packageorder" sourceref="starteventpackageorder6"> <conditionexpression id="sid-c2"> No Side Dish Required </conditionexpression> </sequenceflow> [ ] <task id="packageorder"> [ ] </task> <endevent id="endeventpackageorder"> <incoming>sfoutputpackageorder</incoming> <signaleventdefinition id="outputdefpackageorder" signalref="signalpackageorder" /> </endevent> </process> <process id="sid-processarrangepayment"> <startevent id="starteventarrangepayment3"> <outgoing>sfinputarrangepayment4</outgoing> <signaleventdefinition id="inputdefsid-signalcalculateprice" signalref="signalcalculateprice" /> </startevent> <task id="arrangepayment"> [ ] </task> [ ] </process> [ ] <signal id="signalcalculateprice" /> <signal id="signalarrangepayment" /> <signal id="signalpackageorder" /> <signal id="signalbakepizza" /> [ ] </definitions> (c) Monique Snoeck 25/04/

20 PIM2PSM Deploy each split business process to a different process engine E.g. Activiti BPMN2.0 process engine Distribute the deployed process engines throughout the IT infrastructure e.g. Close to necessary data warehouse locations (c) Monique Snoeck 25/04/ Business Process Redesign Changes are made to the original Business Process Model Re-Deployment of a split process engine is only done if the split process is affected by the change Decentralization Algorithm Business Process Modeler Changes BPMN Model Changes PIM Only for affected process objects Split BPMN Split Split BPMN Model BPMN Model Model PSM PSM PSM Re-Deploy and Re- Distribute affected split processes Process Process Engine Process Engine Engine (c) Monique Snoeck 25/04/

21 PhD Geert Monsieur Service composition 41 (c) Monique Snoeck 25/04/2011 (c) Monique Snoeck Service Composition Combining services into service-based systems (c) Monique Snoeck 25/04/

22 Coordination in service compositions Business Process as blueprint Coordination = Control Flow + Data Flow (c) Monique Snoeck 25/04/ Implementing control and data flow We too often fail to precisely translate business process into coordination scenarios We need (better) tools! It s too complex! We too often work ad-hoc We need to do the same things over and over again (c) Monique Snoeck 25/04/

23 PIM2PSM transformation rules implemented in Java PIM (input): BPMN 2.0 (XML) Service and Data Providers (WSDL files) configuration: Coordination Model (XML) = selection of patterns PSM (output): BPEL (and WSDL) files for each participating service in the service composition Java (c) Monique Snoeck 25/04/ Using MDA to automate the design of service interactions Business Process Modeler Pattern-based coordination BPMN Model PIM BPEL BPEL + WSDL BPEL + WSDL File+ WSDL File File PSM PSM PSM Deploy and distribute BPEL BPEL Engine BPEL Engine Engine (c) Monique Snoeck 25/04/

24 Business Process (sequence + data dependencies) (1) Book flight (2) Book hotel (3) Book car Flight number Internet Tool for Pattern-based Coordination in Process-based Service Compositions Selection of patterns Coordination Scenario (BPEL/WSDL files) Agenda Basic Concepts behind MDA work Prototyping MERODE Enterprise models Event-based Distributed Processes (Pieter Hens) Service Coordination (Geert Monsieur) Lessons learned (c) Monique Snoeck 25/04/

25 MDA languages UML 2.1 has become enormous and unwieldy complexity tends to impede successful adoption some of the constructs in UML 2.1 are nearly semantics-free (e.g., use cases). semantics carry the meaning essential to enable automation ==> lack of semantics at all levels makes the production of automated MDD tools difficult DSL are not a fundamental solution: boil down to the same issues on semantics. (c) Monique Snoeck 25/04/ Key Success Factors for MDA semantics, Semantics, SEMANTICS Quality of the MODELS Garbage In Garbage Out Platform independent & Abstract imprecise & ambiguous! Quality of the MAPPING Quality In + Mess it up Garbage Out! Design Software Architecture key to Adaptable & Flexible software Mapping requires PERSISTENT MODELS, in machine readable form 4 Layer Metamodelling Architecture STANDARDS & TOOL Integration (c) Monique Snoeck 25/04/

26 Avoid Incomplete, fuzzy semantics Example: transform ER-Model into an existence dependency graph NOT Frozen Frozen LIBRARY 1 * COPY * 1 TITLE Identical Representation Identical meaning?? Frozen LIBRARY * 1 COPY 1 1 COPY * 1 LOCATION TITLE (c) Monique Snoeck 51 Lessons Learned Productivity? MERODE code generation: approximately 6 PM work Intensive testing required after +/- 1 years of use bug-free Yearly used to generate 200 applications Documentation PIM requires its own documentation Documentation of transformation is essential the need for documentation does not disappear Portability & Interoperability Yes, but new transformations need to be defined (c) Monique Snoeck 25/04/

27 Lessons Learned New Problems? Constraints imposed on PIM could depend on target platform e.g. JAVA reserved words Hidden assumptions in transformations complicates combining transformations Debuggers for transformations? error in generated code can have two sources: error in source model or error in transformation backward tracing facilities would be useful MDE is addictive (c) Monique Snoeck 25/04/ MDA : Where to next? CASE was not a success Will MDA be a success? Growth of available tools (Rational, Eclipse, OptimalJ,...) Silo problem reduced better integration of tools through XML standards interpretation of XMI is still a problem == > semantics!! more Open Source tools available evolution to de facto standards Students trained at modelling with tools (c) Monique Snoeck 25/04/