Dynamic Service Composition with QoS Assurance Feb. 26-27, 2009 Jing Dong UTD [email protected]...

Dynamic Service Composition with QoS Assurance

Feb. 26-27, 2009

Jing [email protected]

Farokh Bastani [email protected]

I-Ling [email protected]

Net-Centric Software & Systems ConsortiumKick-off Meeting

204/18/23 Net-Centric Software & Systems Consortium

Problem Description


• Dynamic and reconfigurable service compositions• Frequently changing business requirements and conditions• Dynamic and volatile nature of system and Web environments• Non-stop runtime environments

• Modeling service compositions• Complexity in large service composition processes• Lack of service abstraction for capturing the relations among services

• QoS assured net-centric systems• System QoS and dependability requirements are very important• System needs to dynamically adapt

Automated and dynamic service composition• Tool support service compositions satisfying QoS requirements


Existing Solutions


• Service composition• BPEL4WS – Only Functional, no semantics• Semantic Web services (OWL-S) – Lack the support for capturing the

relations among services

• Service discovery• Individual service selection based on QoS criteria – Focus on the selection of

individual services• Service selection based on composite QoS behavior – Consider greatly

simplified QoS property aggregation functions

• Service composition analysis• Hardware failures for reliability analysis – No critical software faults• Simple summation of fixed latency for timing analysis – No consideration of

the impact of newly added flows


Our Solution


• Service composition• Abstract service, service modeling and transformation• New planning technique: ProcedurePlan

• A planner that can generate procedures• Much more scalable than all existing planners

• Service discovery• Configurable services for QoS Tradeoffs

• Service composition analysis• Compositional QoS analysis for service composition• Service-driven compositional reliability model and timing analysis• Mutual trust evaluation protocol for trustworthiness• Three-level compositional QoS analysis technique


Our Solution (cont.)


CQAD Framework

Specification Parsing

Compositional QoS Prediction

Decision Making

Reliability Prediction Algorithms

Timing Prediction Algorithms

… Genetic Algorithm … Particle

Swarm Algorithm

Parsers for various QoS specification

languages

Extended OWL-S Ontology

System QoS-Req

Goal Specification GUI

Functional Goals

Extended Planner

Service Patterns

Functional Composer

Composition Plan

Extended UDDI

Ontology Analyzer

OWL-S Abstract Service

Generator

OWL-S Abstract Service

Service

Profile

Process

Grounding

Instance

QoS-Assured Composition

Plan

Concrete Web

Services

Web services QoS-capabilities

Composition Logic

Instance Pool

Pattern Generator

User


Experimental Plan


• Current status• Pieces of techniques and tools• Planner, QoS analysis framework with decision process, etc.

• Future plan• Build an integrated system synthesis framework

• Develop a robust planner and a problem modeling framework• Develop QoS compositional analysis techniques and tools

• Investigate partial planning techniques• When the goal cannot be reached with existing components/services

• Investigate the power of the synthesis framework using real-world examples


Industry Member Benefits


• Share the techniques and tools which can• Dramatically reduce software development cost and

time• Automate software customization process• Greatly enhanced capability in Web service

composition

• Expected from industrial partners• Provide real-world applications/scenarios

• Used to validate the applicability of our solutions• Need close collaboration to understand and potentially

modify the case and the scenarios

• Provide development time/cost estimates• Used to compare with the time/cost of our approach


Deliverables and Budget

Duration Total 1 Graduate Studentsat $25000 stipend + $10000 Tution per year 2 years 700000 Faculty months at $10000 per faculty effort 2 yearsTravel at 1500 per conference travel 2 years 3000Total Cost 73000


Year 1 6 months Abstract service modeling. Defining service relationships. Dynamic updating service ontology and super instance. Algorithm for populating the instance pools. Categorizing the service parameters

6 months Pattern-based planning techniques for service composition. Pattern-based service composition. Service pattern extraction. Planning techniques for complex compositions.

Year 2 6 months QoS-assured service composition. Service-centric compositional real-time analysis. Service-driven compositional reliability analysis. Trustworthiness analysis for service composition. Configurable web services model.

6 months Integrate the planner, synthesis environment, and QoS analysis tools. Perform development cost/time analysis and comparison. Case studies to validate the approach.

(Requires close collaboration with industrial partners to provide the case study, discuss the scenarios and potential modifications, provide cost/time data of the existing development process.)

Topic/project/effort descriptionNet-Centric Software & Systems ConsortiumKick-off Meeting

• Develop a tool kit to allow automated composition of web services

• Develop evaluation suite to evaluate and analyze service composition with QoS requirements

• Validate our approach on many real-world applications

Abstract service captures the relationships among the services and raise the level of abstraction

Service selections should consider not only the functional and semantic aspects, but also QoS requirements

Service composition analysis with QoS assurance

Techniques and tools to analyze and evaluate these compositions

Automated service composition can significantly save development time and improve system quality

MAIN ACHIEVEMENT:

Developed abstract service to allow service composition and analysis at a higher level

Developed compositional genetic algorithms to efficiently select compositions that can optimally achieve QoS requirements

Developed techniques to evaluate and analyze service composition with QoS assurance

HOW IT WORKS:

The most challenging issues in reconfigurable service composition with QoS assurance:

(1) How to provide a holistic view of multiple QoS properties under changing business requirements?

(2) How to dynamically compose the web services that satisfy QoS criteria?

(3) How to analyze the service compositions?

Our techniques provide partial answers to these issues.

ASSUMPTIONS AND LIMITATIONS:

• Each service has well-defined interface that describes the functional and semantic properties

• Service implementation is hidden from its interface

• Generalization of our approach to many applications is to be validated

Semantic Web Services

Dynamic Service Composition

Service Selection with QoS requirements

Analysis with QoS Assurance

A tool kit for composition of web services with QoS assurance

•Modeling service composition at a higher level of abstraction

•Developing algorithms for service selections with QoS criteria •Analyzing service composition •Evaluation techniques can effectively assess the service composition with a high degree of confidence, and can be used to guide the system design process

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Service composition

AbstractionModelingAnalysis

Comparing results computed by different composition algorithms on different QoS criteria

Dynamic Service Composition with QoS Assurance Feb. 26-27, 2009 Jing Dong UTD [email protected]...

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