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Model-Driven Engineering Of Component Systems

Institute for Software Integrated Systems. Vanderbilt University Nashville, Tennessee. Model-Driven Engineering Of Component Systems. Krishnakumar Balasubramanian James Hill Dr. Douglas C. Schmidt {kitty, hillj,jules,schmidt}@dre.vanderbilt.edu. Presentation Roadmap. Research Challenges

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Model-Driven Engineering Of Component Systems

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  1. Institute for Software Integrated Systems Vanderbilt University Nashville, Tennessee Model-Driven Engineering Of Component Systems Krishnakumar Balasubramanian James Hill Dr. Douglas C. Schmidt {kitty, hillj,jules,schmidt}@dre.vanderbilt.edu

  2. Presentation Roadmap • Research Challenges • Software System Analysis • Component System Integration • Component System Optimization • Demonstration Section • Scenario • Question • Capability Demo • Enabling Technology • Concluding Remarks • December Demo • Benefits & Roadmap

  3. Model-Driven Engineering Technologies System Integration Technologies System Optimization Technologies System Analysis Technologies

  4. sensor 1 (main) error recovery effector 1 (main) planner 2 planner 1 sensor 2 configuration effector 2 SLICE System Scenario (1/2) SLICE application string consists of: • 2 sensors • 2 planners that process data from the sensors • Configuration component responsible for converting planner output into configuration input for effectors • Effectors that perform action based on configuration parameters

  5. sensor 1 (main) error recovery effector 1 (main) planner 2 planner 1 sensor 2 configuration effector 2 SLICE System Scenario (2/2) Deployment & Performance Requirements • Critical path deadline is 350 ms • main sensor to main effector through configuration • Components in the critical path must be deployed across multiple hosts • Main sensor & effector must be deployed on separate hosts • Three hosts • One database is shared between all hosts

  6. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing System infrastructure components developed first Application components developed after infrastructure is mature

  7. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing Finished development System integration & testing Integration Surprises!!!

  8. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing Still in development Ready for testing Complexities • System infrastructure cannot be tested adequately until applications are done

  9. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing Overall performance? Complexities • System infrastructure cannot be tested adequately until applications are done • Entire system must be deployed & configured properly to meet QoS requirements • Existing evaluation tools do not support “what if” evaluation

  10. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing Meet QoS requirements? Key QoS concerns • Which deployment configurations meet the QoS requirements?

  11. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing Performance metrics? Key QoS concerns • Which deployment configurations meet the QoS requirements? • What is the worse/average/best time for various workloads?

  12. Level of Abstraction Development Timeline Software System Analysis Challenge: Serialized Phasing System overload? Key QoS concerns • Which deployment configurations meet the QoS requirements? • What is the worst/average/best time for various workloads? • How much workload can the system handle until its QoS requirements are compromised? It is hard to address these concerns in processes that use serialized phasing

  13. Software System Analysis in 10 Years • Validate Design Rules • System will adhere to system design specifications • “Correct-by-construction” • Ensure Design Conformance • System will be deployed & configured to conform to system design rules • Conduct “What If” Analysis • QoS concerns can be analyzed prior to completing the entire system • e.g., before system integration phase The cycle is repeated when developing application & infrastructure components

  14. Software System Analysis in 3 Years Component Workload Emulator (CoWorker) Utilization Test Suite Workflow (CUTS): • Develop MDE tools which allow emulation of real components on target infrastructure • Develop analysis tools to evaluate & verify QoS performance • Develop framework to allow instrumentation of “real” components • Develop framework for intermixing of emulation components with “real” component Enable testing on target infrastructure early in development lifecycle

  15. Software System Analysis 2006 Demos • August • Model-Driven Software System Analysis Tools • Automated generation of emulation components • December • Develop CoWorkEr emulation framework in multiple SOA technologies • Microsoft .NET web services • J2EE web service • Integration of CBML & WML into other MDD tools • GEMS

  16. Software System Analysis Motivating Question? How can system engineers analyze the performance of an application on the actual deployment environment before the development of application components is complete?

  17. Emulation Framework Enabling Technology: Model-Driven Software System Analysis • The Component Behavior Modeling Language (CBML) & Workload Modeling Language (WML) is used to define the behavior of CoWorkEr components in a PICML model • CoWorkEr implementation is generated on top of a component framework that contains a benchmarking aspect

  18. Component System Integration • System refers to software systems built using • Service-Oriented Architecture (SOA) technologies like Web Services • Component middleware technologies like Enterprise Java Beans (EJB), CORBA Component Model (CCM) • Integration can be done at multiple levels • Process Integration • Functional Integration • Data integration • Presentation Integration • Portal Integration • System Integration refers to functional integration done via • Distributed Object Integration • Service-Oriented Integration

  19. Component System Integration: Unresolved Challenges • Component middleware is getting a lot more declarative • Management of diverse metadata & configuration of middleware is proving to be error-prone • Current practice attempts integration in a manual fashion • Inappropriate level of abstraction • Integrators need to learn enough of every technology • Lack of automated tools limits scalability of integration • Total system performance determined by “Quality-of-Integration” (QoI) • QoI refers to the effect of the integration on the functional & QoS properties of the integrated system • Along with “Quality-of-Implementation”

  20. Component System Integration: Unresolved Challenges • Lack of tool support for key integration activities • Needed to scale up the integration & deployment process • Relieve the system integrator from ever-changing platform-specific details aka “accidental complexities” • Unable to define constraints at the whole system level • Needed to evaluate service-level agreements before integration • Check system consistency before & after integration • Lack of infrastructure to apply system level optimizations • Needed to automate and optimize the generated glue-code • (Re-)Target emerging & new middleware technologies

  21. Component System Integration in 10 Years • Provide abstractions for expressing system level design intent • Automation of key system integration activities • Generation of integration glue-code • Generation of middleware & deployment metadata • Integrated system satisfies Service Level Agreements (SLAs) • De-emphasize programming-in-the-small • No more whack-a-mole approach to system integration • No more violation of Don’t Repeat Yourself (DRY) principle Tools to integrate “systems-in-the-large”

  22. Component System Integration in 3 Years • Develop tools to allow functional integration of two sample COTS technologies • CCM • Web Services • Express & evaluate service level agreements between applications built using • CCM • Web Services • Enable integrators to evaluate QoI using different • Integration topologies, e.g., Message Bus, Point-to-Point, Broker (Indirect/Direct), Publish/Subscribe • Integration architectures, e.g., Java Business Integration (JBI), Service Component Architecture (SCA), Windows Communication Foundation (WCF)

  23. Component System Integration 2006 Demos • August • Use CCM & Web Service as sample technologies to be integrated • Show automatic generation of Web Service implementation from model • December • To be defined in discussion with LMCO STI personnel

  24. Component System Integration Motivating Questions? • How do you integrate systems that were not designed to work together? • How do you predict the effects of system integration before the actual integration? • How do you automate key system integration activities?

  25. Demonstration Scenario

  26. Enabling Technology: Model-Driven System Integration • Model-based approach to system integration • Develop System Integration Modeling Language (SIML), a DSML for system integration • Hierarchical composition of DSMLs • Composed from multiple sub-DSMLs • PICML  CCM • WSML  Web Services • Each sub-DSML is used as a model library • Built in a re-usable & extensible fashion • “Open-Closed” principle • New languages can be added; existing ones reused • Preserve existing investment • Tools for sub-DSMLs work seamlessly in composite DSML

  27. Enabling Technology: Usage Scenarios • SIML consists of DSMLs for each technology being integrated • Targets system developers & integrators • System Developers • Use DSML of corresponding technology • Assists in automating key deployment activities • Used during development of individual sub-systems • System Integrators • Use the integration DSML • Assists in combining sub-systems together • Used during integration testing of the whole system

  28. Component System Optimization • Middleware tries to optimize execution for every application • Collocated method invocations • Optimize the (de-)marshaling costs by exploiting locality • Specialization of request path by exploiting protocol properties • Caching, Compression, Various encoding schemes • Reducing communication costs • Moving data closer to the consumers by replication • Reflection-based approaches • Choosing appropriate alternate implementations

  29. Component System Optimizations: Unresolved Challenges • Lack of application context • Missed middleware optimization opportunities • E.g., every invocation performs check for locality • Optimization decisions relegated to run-time • Impossible for middleware (alone) to predict application usage • Settle for near-optimal solutions Cannot be solved efficiently at middleware level alone!

  30. Component System Optimizations: Unresolved Challenges • Overhead of platform mappings • Blind adherence to platform semantics • Inefficient middleware glue code generation per component • Example: Every component is created using a Factory Object • Overhead of external components similar to internal ones • Standard component models define only virtual assemblies

  31. Component System Optimization in 10 Years • Generate application specific components for a product-line architecture • Optimize middleware in an application-specific fashion • Improve performance • Reduce static & dynamic footprint • Eliminate mis-optimizations • No changes to individual component implementations • Customizable & completely application transparent

  32. Component System Optimization in 3 Years • Identify sources of overhead in large-scale component-based system of systems • Develop component assembly optimizer which eliminates these sources of overhead • Use CORBA Component Model as a test bed • Apply optimization technology to a variety of scenarios • PCES Emergency Response System (30+ components) • ARMS GateTest scenarios (100+ components) • Scenarios with & without inherent hierarchy

  33. Component System Optimization Motivating Question? How do you custom optimize individual component implementations based on the global system composition properties & usage scenario without requiring any changes to the component implementation?

  34. Component System Optimization: December Demo • Baseline for comparison • Performance & footprint (with vanilla CIAO) • Emergency Response System (30+ components) • ARMS GateTest scenarios (100+ components) • Scenario with & without inherent hierarchy • Reduce static & dynamic footprint • n = no. of internal components, x = total no. of components in the assembly • Reduce from n factories to 1 factory

  35. Component System Optimization: December Demo • Improve performance • t = no. of interactions between components within an assembly • Transform t collocation checked calls to t unchecked calls • Eliminate mis-optimizations • Check incompatible POA policies • Incompatible invocation semantics (oneway or twoway) • No changes to individual component implementations • Eliminate need for a local vs. remote version • Customizable & application transparent • Investigate feasibility of applying optimizations to Web Services (in addition to CCM)

  36. Concluding Remarks • Our research focuses on Model-driven Engineering (MDE) solutions • Software System Analysis Tools (CUTS/PICML/WSML) • Benefits • Reduces complexities with serialized phasing in large-scale systems • Automates generation of distributed emulation infrastructure • Component System Integration Tools (SIML) • Benefits • Provides infrastructure to evaluate service level agreements • Automates generation of integration glue-code • Component System Optimization Tools (PICML/WSML) • Benefits • Perform optimizations on a “system-of-systems” scale Tools can be downloaded from www.dre.vanderbilt.edu/CoSMIC/

  37. Enabling Technology: Component Assembly Optimizer • Component Assembly Optimizer • Uses system models as input • Combines • Information about the system-as-a-whole as well as individual components from the model • Catalog of (feature, perf. overhead),(feature,dependent features) & (feature, incompatible features) tuples of the underlying middleware technology • To optimize globally, i.e., across the whole “system-of-systems”, the • Generated middleware glue code • Configuration of underlying middleware • Generated deployment metadata

  38. Target Scenarios • “System of Systems” with portions exhibiting • Hierarchy • No hierarchy • Built using COTS component/SOA technologies • Web Services • CCM • EJB • Specific deployment scenario • Information about • Composition structure of systems/component assemblies • Desired QoS policies • Target deployment domain

  39. Solution Approach: Physical Assembly Mapping • Devise mapping for physical component assembly • Exploit hierarchy of application structure to fuse (make a component internal) at multiple levels in hierarchy • Experimentally validate right depth of hierarchy to stop fusion • Too deep – Single giant blob • Too shallow – Potentially lower benefits

  40. Component System Optimization: What’s missing? • Lack of high-level notation to guide optimization frameworks • Missing AST of application

  41. Component System Optimization: What’s missing? • Lack of high-level notation to guide optimization frameworks • Missing AST of application • Emphasis on detection at run-time (reflection) • Additional overhead in the fast path • Not suitable for all systems • Not completely application transparent • Requires providing multiple implementations • Optimization performed either • Too early, or too late

  42. Steps Involved in Integration Using SIML • Generate a CCM DSML model from the IDL definition of application components • Generate a WSDL file from the IDL of the component(s) to be exposed as Web Service(s) • Import the CCM model into integration DSML; define connections between CCM components to assemble application • Generate a WSDL DSML model from generated WSDL • Import the Web Service model into integration DSML

  43. Steps Involved in Integration Using SIML • Annotate the WSDL model to specify deployment information like WSDL port bindings (host name, host port number, URI including namespace of service et al. • Generate CCM deployment descriptors • Generate the type-specific proxies, i.e., integration glue-code • Generate Web Service deployment descriptors including updated WSDL, web container hosting artifacts

  44. SIML Benefits • Develop integration DSML in a modular & extensible fashion • Model-library based approach • Allows re-use of existing platform DSMLs • New platforms can be added easily

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