Survey of Dynamic Web Service Composition Techniques. Presented By Atif Alamri ( firstname.lastname@example.org ) Mohamad Eid ( email@example.com ). ELG 5121 Multimedia Communications Prof. Abdulmotaleb El Saddik Nov. 1, 2005. Outline. Introduction Web services architecture
Atif Alamri (firstname.lastname@example.org )
Mohamad Eid (email@example.com )
Prof. Abdulmotaleb El Saddik
Nov. 1, 2005
(1) Register & publish web service using its WSDL file
(2) Search for web service and retrieve the URL for its WSDL file
(3) Interact with the web service
XML formatted messages
ApplicationWeb services architecture
The customization of software based on individual needs of a user can be made dynamic
The capabilities of the application can be extended at runtime
Users can continue to interact with the old services while composition of new services is taking place
unlimited number of new services can be created from limited set of service components
Composition is useful to provide runtime specified services
Dynamic composition is the only means to change the behavior of running applications
New versions of components can be introduced, thus making upgrading possible
Not necessarily true
The extra requirement is a component model that supports dynamic binding and runtime extensibility of components
Context dependencyComposition techniques 1/6 Runtime reconfiguration using wrappers
Encrypted()Composition techniques 2/6 Runtime component adaptation
Layer message handler
Service Provider B
Service Provider CComposition techniques 4/6 Workflow Driven Composition
Credit card payment
OwnedBYComposition techniques 5/6 Ontology Driven Composition
Runtime Reconfiguration Using Wrappers
A wrapper is used to make the component capable to interact with a new component.
Runtime Component Adaptation
Adapting components into new services by changing the interfaces and/or behavior of the component at runtime.
Language Driven Composition
Language specifies the component adaptation and configure coordination and policies.
Workflow Driven Composition
Build services to an abstract process and constraints and generate an executable process.
Ontology Driven Composition
Ontological descriptions and relationships of web services are used to compose web services.
Using composability rules to check if two services are composable.Dynamic Composition Techniques: Summary
Decomposes user query into a set of requirements
Decomposes user requirements into an abstract service and specify the proper services.
Uses one of dynamic composition techniques to answer the ‘how’ question of composition
To verify that the composite service satisfy the user’s query
Checks for functional and/or nonfunctional QoS parameters
Executes the composite service by invoking individual components and matching interfaces
Showing the status of the component services and handling exceptional states
Provides controllability on composition, execution, and recovery processes
To describe and advertise the composite service to support recursive composition
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