Intermediate presentation Simon Zambrovski simon@zambrovski.org Tutor: Muhammad Farhat Kaleem Web...

Intermediate presentation

Simon Zambrovskisimon@zambrovski.org

Tutor: Muhammad Farhat Kaleem

Web service transactions in JXTA network

07.04.2004 2

Agenda

WS-Coordination WS-Transactions Conceptual solutions Apache AXIS Technical solutions

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Web Service coordination (WS-Coordination) Coordinator

Activation Service Registration Service

Initiator Getting a context (Activation Service) Propagating context to participants

Participant Register (Registration Service)

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Web Service transactions (WS-AT & WS-BA) General

Built on top of WS-Coordination Extends it with own protocols

Atomic Transactions Short lived transactions Protocols : Completion, Volatile 2PC, Durable 2PC

Business Activities Long lived activities Protocols

BA with participant completion, BA with coordinator completion e.G. BA with Participant Completion (simplified)

Active Completed EndedClosing

Compensating

completed close

compensate compensated

closed

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Communication Scenario (client view)Transaction Middleware Service

Webservice

Webservice

Client

begin

end

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Message interception (Proxy)

ProxyService

Transaction Middleware Service

Webservice

Webservice

Client

begin

end

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Webservice

Coordination

ProxyService

Coordination Middleware Service

Context

register

Transaction Middleware Service

Client

begin

end

Coordination Participant

create

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ActiveActive

Business Activity (Participant Completion)

Webservice

Coordination Middleware Service

completed

Client

Coordination Participant

close

CompletedClosing CompletedClosing

closed

Ended Ended

confirm

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Apache AXIS What is AXIS?

A Web Service framework (client and server)

What is the main idea? The messages are passed and processed The processing units are called handler organized in chains

Why it is so useful? Possibility to write own handler and chains

Why did I choose Apache AXIS? Open source Extensible Good requirement coverage Works with external serialiser (e.g. Castor)

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Technical Solutions Proxy

AXIS-Handler on the client side Proxy Service as message-based AXIS Web Service

Mapping between business and coordination Usage of Trace from Dr. Marcus Venzke Mapping stored in XML-configuration file Handler intercepting messages

JXTA Realised as AXIS-Transport-Handler Used for communication behind the Proxy Service Has no side effects for the client

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Thank You for Your AttentionQuestions?

Further information:http://www.simon.zambrovski.org/

Contact:simon@zambrovski.org