1. Component-based System Integration via (Meta)Model Composition
4/25/2017
Component-based System Integration via (Meta)Model Composition
Krishnakumar Balasubramanian, Douglas C. Schmidt, Zoltán Molnár, Ákos Lédeczi
Kitty, here are my main comments:
. You MUST work on not looking at your slides & reading them. This is very disconcerting & will cause your audience to not pay attention to what you’re saying.
Vanderbilt University Nashville, Tennessee
Institute for Software Integrated Systems

2. Motivating Application
System Domain
Shipboard Computing
On-demand situation awareness
Integration with human operators
Distributed System
Different client applications
Differentiated services to clients
Originally built using CORBA Component Model (CCM)
Need to integrate with W3C Web Service Clients

3. Component-based System Integration
Integration can be done at multiple levels
Data integration
Presentation Integration
Portal Integration
Process Integration
Functional 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)
System Integration refers to functional integration done via
Distributed Object Integration
Service-Oriented Integration

4. Functional Integration Challenges (1/5)
Choosing an appropriate level of integration
Select elements from the different technologies
Selection Criteria
Number of normalizations
To/from native types
Flexibility of deployment
In-process/Out-of-process
Evolving the integration architecture
Increasing the number of peers integrated
Availability of platform-specific infrastructure
OS, languages

5. Functional Integration Challenges (2/5)
Reconciling differences in interface specifications
Map interface specifications between different technologies
Datatype Mapping
e.g., CORBA IDL to Web Services WSDL
Exception Mapping
e.g., SOAP faults to CORBA Exception
Language Mapping
Different source/target implementation languages
Limited scope at level of functional integration
Restricted to out-of-process IPC

6. Functional Integration Challenges (3/5)
Reconciling differences in implementation technologies
Map low-level technology details such as networking, discovery
Protocol Mapping
e.g., Internet Inter-ORB Protocol (IIOP) in CCM vs. SOAP in Web Services
Discovery Mapping
e.g., CORBA Naming Service vs. UDDI repositories
Quality of Service (QoS) mapping
Ensure service-level agreements are met

7. Functional Integration Challenges (4/5)
Managing deployment of subsystems
Declarative notations used to capture various configuration options
e.g., CCM deployment descriptors, .NET assembly manifests
Functionality of system depends on correct configuration of metadata
Development-time default values different from production values
e.g., security configuration of Web Servers hosting Web Services

8. Functional Integration Challenges (5/5)
Interoperability issues
Multiple implementations of same middleware technology
Differences between implementations
e.g., Java Web Services stack vs. .NET Web Services stack
Problems show up only during system integration
e.g., existence of standards like Web Services-Interoperability (WS-I)
Need to deal with interoperability issues in a less than ideal world

9. Model-Driven Engineering (MDE)-based Solution
System Integration Modeling Language
Developed using Generic Modeling Environment (GME)
Part of Component Synthesis using Model-Integrated Computing (CoSMIC) toolchain
Capture elements & dependencies visually
Define “static semantics” using Object Constraint Language (OCL)
Defines “dynamic semantics” via model interpreters
Generates domain-specific artifacts

10. System Integration Modeling Language (SIML)
Hierarchical composition from multiple sub-domain-specific Modeling Languages (DSMLs)
CCM  Platform-Independent Component Modeling Language (PICML)
Web Services  Web Services Modeling Language (WSML)
Built in a reusable & extensible fashion
“Open-Closed” principle
New languages can be added; existing ones reused
Preserve existing investment in tools
Existing tools work seamlessly in composite DSML

11. Key Properties of (Meta-)Model Composition
Representation of independent concepts
Concepts in sub-DSMLs preserved, i.e., no merging of independent concepts
Allows Import/Export
Supporting model evolution
Sub-DSMLs packaged as read-only model libraries
Changes to original DSML propagated through library refresh
Partitioning model namespaces
Sub-DSMLs assigned separate namespaces
Handling constraints
Namespaces used to provide appropriate context for constraint evaluation

12. Enabling Technology: Usage Scenarios
SIML 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 of the whole system

13. Resolving Challenge 1 : Choosing Integration Level
Combination of pre-defined & customizable integration levels
Pre-defined interactions
CCM Ports  Web Service Ports
User-defined interactions
Component level
Assembly level
SIML defines new interactions between CCM ports and Web Services ports
Allows integration of other middleware technologies
e.g., Enterprise Java Beans

14. Resolving Challenge 2: Reconciling Differences in Interfaces
SIML provides a set of tools idl_to_wsdl, idl_to_picml, WSDLImporter
Performs datatype mapping
Maps CORBA datatypes to WSDL datatypes
Performs exception mapping
Maps CORBA exceptions to WSDL faults
Both IDL and WSDL can be directly imported into models
Limited language mapping
Maps ISO/ANSI C++ to Microsoft C++/CLI

15. Resolving Challenge 3: Handling Implementation Differences
Resource Adapters are typically used to bridge implementation differences
SIML implements resource adapters via Gateways
Automatically generates gateways from models
Perform protocol mapping
IIOP SOAP mapping
Perform discovery mapping
Connects to CORBA Naming Service
Configurable gateway generation
GSOAP, Microsoft .NET Web Services

16. Resolving Challenge 4: Managing Heterogeneous Deployment
Deployment of sub-systems requires different mechanisms
SIML can use existing tools for individual sub-system deployment
Possible because of model composition
Deployment metadata configuration & generation
Directly from within SIML
CCM
DeploymentPlan.exe
Web Services
WSDLExporter.exe

17. Resolving Challenge 5: Handling Interoperability Differences
Knowledge of sub-DSML technologies built into SIML
Allows compensating for interoperability differences
idl_to_wsdl.exe
Maps IDL to WS-I defined subset of WSDL
GatewayGenerator.exe
Inter-operable subset of RPC encoding
WSDLExporter.exe
Interoperable XML namespaces in WSDL
Newly discovered incompatibilities can be worked around 

18. Related Work Integration Evaluation Tools
Evaluate integration strategy and tools, e.g., IBM’s WebSphere
System Execution Modeling Tools
Smith, C., & Williams, L. (2001). Performance Solutions
Integration Design Tools
UML profile for Enterprise Application Integration (EAI)
Integration Patterns
Hohpe, G., & Woolf, B. (2003). Enterprise Integration Patterns
Resource Adapters
Java Messaging Specification & J2EE Connector Architecture
IBM’s MQSeries (IBM, 1999), Microsoft BizTalk Server
Integration frameworks
Semantic Web (OWL), GRID System Integration (Foster, 2002), QoS-aware service composition (Zeng et al., 2004)
Integration Quality Analysis
Web Service-Level Agreement language (WSLA) (Ludwig, 2003)

19. Available as Open-Source tools http://www.dre.vanderbilt.edu/CoSMIC
Concluding Remarks
Model-Driven Engineering (MDE)-based approach to functional integration of component-based systems
Based on (Meta-)Model Composition
System Integration Modeling Language (SIML)
Domain-Specific Modeling Language (DSML) for functional integration
Composed from DSMLs for two different middleware technologies
CORBA Component Model
Web Services
Available as Open-Source tools

20. Questions?