RTCCM Meeting Agenda & Overview of RTCCM

1. RTCCM Meeting Agenda&Overview of RTCCM Nanbor Wang Department of Computer Science Washington University in St. Louis nanbor@cs.wustl.edu http://www.cs.wustl.edu/~nanbor/presentations/RTCCM-meeting.ppt

2. Meeting Schedule http://www.cs.wustl.edu/~nanbor/projects/CIAO/project-kickoff.html

3. Extending CIAO Session Schedule • Kokyu - Chris Gill • SCTP - Gautam Thaker and Patrick Lardieri • IntServ/DiffServe - Irfan Pyarali • FT-CORBA - Chris Gill, Balachandran Natarajan, and Joe Cross • RT-Notification Service - Irfan Pyarali • MIC/MDA - Aniruddha Gokhale, Ted Bapty, Sandeep Neema, and Jeff Gray • QuO/QoSket - Craig Rodrigues

4. Presentation Overview • 10-minute CCM Overview • Research problems and proposed approaches • Project Timeline Evolution of DOC Middleware QoS Provisioning Abstractions

5. Limitation with the CORBA 2.x Object Model • Application developers and system integrators are forced to play multiple roles • Application functional component developers • tightly coupled application modules • Computational resource provisioners • ensuring the availability of common object services • ad-hoc management • System configurators • boiler plate code • manual application deployment • Resulting in tight couplings • Brittle, non-standard implementation • Hard to adapt and maintain • Increase time-to-market

6. Separation of concerns: Run-time environment configuration Connections between objects & run-time Composition of objects Support run-time object composition Component: a reusable entity Container: a standardized environment for components to interact with run-time & vice versa Component Server: a generic server process (also called application server) Packaging and Assembling tools: collection of tools to package and compose components into deployable assemblies Deployment mechanism: for deploying component assemblies to component servers Promising Solution: Component Models • J2EE (EJB), COM+ & CORBA Component Model (CCM)

7. The CORBA Component Model (CCM) • Enhances CORBA Object Model • Provides common run-time environment • component servers • containers • Uses metadata to describe application composition, resource allocation, and infrastructure configurations • component dependencies • component connections • component configuration • component run-time services, e.g., transactional, persistence state

8. The CCM Big Picture implementer designers Home Properties Component Properties Programming Component Interconnection Definitions IDL/CIDL File User's Code Language Tools IDL/CIDL Default Properties Compiler assembler CORBA Stubs, Skeletons Implementation Component Package Assembly Packaging CORBA Component Tool Component Tool Assembly Package Package Component packager Descriptor Assembly Descriptor softpkg Deployment User written file Descriptor CORBA deployer Component Tool Compiler Package Generated files Source: OMG CCM Tutorial by Phillipe Merle

9. Current CCM Fails to Address Advanced QoS Requirements QoS-enabled CCM ≠ CCM + RT CORBAWhy doesn't running a RT ORB beneath CCM make it a QoS-enabled CCM implementation? • Applications requires a wide variety of infrastructure support, e.g., QoS guarantees • Plain CCM has no mechanisms to specify and enforce real-time QoS policies • QoS policies need to be assured end-to-end for components & connections • Ensuring QoS policies in component implementations leads to: • QoS mechanisms that are hard to utilize and go beyond component implementations • Component connections • private connections • bandwidth reservation • Component collaborations • Thread pools • Thread borrowing • Tight couplings among component implementations • Difficulty in reusing existing components (without QoS knowledge)

10. QoS-Enabled Component Middleware • Separate the concerns for QoS managements • Separate the roles • Application component developers • QoS assurance mechanism developers • QoS provisioning managers • ORB configurators • Compose QoS assurance mechanisms • ORB – OS • Application-specific Adaptive • Specify metadata for QoS requirements of • components • component connections Extend component middleware to support more advanced infrastructure and resource management

11. Specifying QoS Policies in CCM Applications • Context: • Delay specifying QoS policies till applicationcomposition time • Problems: • CCM specification doesn’t consider QoS policies • QoS policies usually managed via ad-hoc interfaces, e.g., RT policies • QoS Policies can bind to either • Components • Connections • Solution Approach: • Extend composition metadata to incorporate QoS policies • Expected Results: • Implement a CCM deployment framework that realizes extended metadata. • Categorize bindings of QoS policies

12. Supporting QoS Assurance Mechanisms • Context: • Modern applications need to leverage various QoS assurance mechanisms • Problems: • No standard way to support these QoS mechanisms • knowledge of ORB internals required a priori • Unforeseen QoS assurance mechanisms • Solution Approach: • Configure the middleware dynamically • Expected Result: • Extend and implement CCM deployment mechanisms to describe and deploy ORB modules

13. QoS Assurances Require End-to-end Enforcement • Context: Many QoS properties • need to be enforced end-to-end • require some degree of adaptation • Problem: • Lack of standard interaction model with QoS mechanisms • Solution Approach: • Apply meta-programming techniques • Expected Result: • Extend and Implement CCM metadata to configure and compose interceptors/smart proxies

14. Configuring Component Adaptation • Context: • Many QoS properties need to be enforced end-to-end • We need to apply meta-programming techniques to insert adaptive behaviors • Problem: • Components need to adapt as a whole, not as multiple individual interfaces • Solution Approach: • Apply reflective middleware technologies to containers • Expected Result: • Develop QoS-enabled containers in CCM

15. Configuring Client-side Adaptation www.krones.com • Context: • We are applying meta-programming techniques to insert adaptive behaviors for QoS requirements • Objects with same interface may require different adaptive behaviors • Problem: • Coarse-grained existing meta-programming support • Smart proxies – all references • Interceptors – all invocations • Solution Approach: • Control effective meta-mechanisms through CORBA policies • Utilizing extension interface pattern • Expected Result: • Develop mechanisms to associate interceptors and smart proxies with object references via CORBA policies

16. Client-side Policy Aggregates • Context: • Modern systems often require multiple QoS assurance mechanisms • Objects often require multiple adaptive behaviors • Problem: • Ad-hoc configuration interfaces • Brittle client-side implementation • Difficult to update matching client/server policies requiring end-to-end assurance • Solution Approach: • Configure ORB dynamically • Define policy aggregates dynamically using metadata (using Extension Interface pattern) • Expected Results: • Develop a CCM assembly-like client side configuration mechanisms • Define policy aggregates with XML-based descriptors • Package required ORB mechanisms and adaptive strategies • Enable Client to associate objects with named policy aggregates

17. Component-Integrated ACE ORB (CIAO) • Extension to component assembly descriptors • Component and connection QoS specifications • ORB modules • Adaptation modules • QoS-enabled containers • Policy-based adaptation insertion • Client-side policy aggregates • Integrating RT-CORBA & ACE QoS API (AQoSA) • Benchmark and document test applications using various combinations of QoS aggregates

18. Project Timeline CIAO 0.1 alpha release - (TAO 1.3, Oct. 2002) • Extension to CORBA Core • Default implementation of • CCMObject • Navigations • Receptacles • Events • CCMHome • KeylessCCMHome • Partial support for basic container/callback interfaces: • CCMContext, SessionContext • EnterpriseComponent, SessionComponent • HomeExecutorBase interface • Support (hand crafted) monolithic executor implementation • Extension to IDL compiler and Typecode factory. • IDL compiler: shall recognize all CCM keyword extensions but not necessarily generate code for these added keywords. • Adaptive configuration of Notification Service/Event Channels • Partial implementation of Deployment module

19. Project Timeline CIAO 0.2 beta release - (TAO 1.3.x, Apr. 2003) • Support for various RT and QoS Policies • Support for policy-based adaptation mechanism • HomeFinder interface • HomeRegistration interface • Configuration interfaces • Configurator • StandardConfigurator • HomeConfiguration • Other basic container programming interfaces • EntityContext • EntityComponent • Extension to Interface Repository • IDL should generate correct client/server side mapping for component extension • CIDL implementation that generates skeleton implementation for • Navigations, Receptacles, and Events interfaces of a components • component executor and home_executor templates for monolithic component implementation • Complete Deployment implementation, assuming the revised deployment specification will be available

20. Project Timeline CIAO 1.0 release - (TAO 1.4, Oct. 2003) • Transaction module? • CCM2Context, Session2Context, Entity2Context and • PSS functionality? • Support for ExecutorLocator based component implementation • ProxyHomeRegistration interface

21. Bryan Hall Coke machine Men’s room Coffee & tea We are here!