Intermediate presentation Simon Zambrovski Tutor: Muhammad Farhat Kaleem Web service transactions in JXTA network

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

Web Service coordination (WS-Coordination)  Coordinator  Activation Service  Registration Service  Initiator  Getting a context (Activation Service)  Propagating context to participants  Participant  Register (Registration Service)

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) ActiveCompletedEnded Closing Compensating completed close compensate compensated closed

Communication Scenario (client view) Transaction Middleware Service Webservice Client begin end

Message interception (Proxy) Proxy Service Transaction Middleware Service Webservice Client begin end

Webservice Coordination Proxy Service Coordination Middleware Service register Transaction Middleware Service Client begin end Coordination Participant create

Active Business Activity (Participant Completion) Webservice Coordination Middleware Service completed Client Coordination Participant close Completed Closing Completed Closing closed Ended confirm

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)

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

Thank You for Your Attention Questions?  Further information:  Contact: