eb XML Message Service Dept of Computer Engineering

eb. XML Message Service Dept of Computer Engineering Khon Kaen University 168493: XML and Web Services (II/2546)

Outline n n n What and Why Message Service? Functional modules of MSH (Message Service Handler) Packaging n n eb. XML SOAP Extensions Reliable messaging Security Versioning 168493: XML and Web Services (II/2546) 2

Messaging Service Overview n n The eb. XML message service deals with transport, routing, and packaging of messages It uses SOAP with attachment as payload envelope structure n Attachment allows transporting of not only XML data but also non-XML data such as JPG file 168493: XML and Web Services (II/2546) 3

Message Service Overview n Supports high-level semantics needed business transactions n n n Security Reliability Runs over various communication protocols n n n HTTP SMTP FTP 168493: XML and Web Services (II/2546) 4

Message Service Design Goals n n Robust, yet basic, functionality to transfer messages between trading parties Using various existing communication protocols Allowing for messaging reliability, persistence, security, and extensibility Allowing robust, yet low-cost solution 168493: XML and Web Services (II/2546) 5

Message Service Design Goals n n Support both XML-based and non XMLbased business information handler Allow vendors to add robustness and higher performance in their implementation n n Scalability Leverage existing standards 168493: XML and Web Services (II/2546) 6

eb. XML Message Structure Communication Protocol Envelope (HTTP, SMTP, etc. ) SOAP with Attachments MIME Envelope MIME Part Message Package Header Container MIME Part(s) Payload(s) 168493: XML and Web Services (II/2546) Payload Container(s) 7

eb. XML Message Structure: Header Container SOAP-ENV: Envelope SOAP-ENV: Header eb: Message. Header eb: Trace. Header. List … SOAP-ENV: Body eb: Manifest … 168493: XML and Web Services (II/2546) 8

Message Service and SOAP n eb. XML Message packaging comply with n n n SOAP 1. 1 SOAP Messages with Attachments eb. XML Message Service defines a set of namespace-qualified SOAP Header and Body element extensions within the SOAP Envelope 168493: XML and Web Services (II/2546) 9

eb. XML Message Envelope <SOAP-ENV: Header …. > <eb: Message. Header …> … </eb: Message. Header> </SOAP-ENV: Header> <SOAP-ENV: Body …> <eb: Manifest …> … </eb: Manifest> </SOAP-ENV: Body> 168493: XML and Web Services (II/2546) 10

eb. XML SOAP Extensions n SOAP Header extensions n n n n Message. Header Trace. Header. List Error. List Signature Acknowledgment Via SOAP Body extensions n n Manifest Status. Request Status. Response Delivery. Receipt 168493: XML and Web Services (II/2546) 11

eb. XML SOAP Extensions n Message. Header n n Trace. Header. List n n A REQUIRED element that contains routing information for the message as well as other context information about the message An element that contains entries that identifies the Message Service Handler(s) that send and receive the message Manifest n An element that points to any data present either in the Payload Container or elsewhere on the web 168493: XML and Web Services (II/2546) 12

eb. XML Message Service n n eb. XML message service functionality is provided by message service handler Message Service Handlers (MSH), on behalf of applications, perform reliable and secure message delivery 168493: XML and Web Services (II/2546) 13

eb. XML and MSH Application MSH Node Application eb. XML Message Service 168493: XML and Web Services (II/2546) 14

MSH Service #1: Is Remote Partner Reachable? Application MSH Node Ping MSH Node Application Pong Eb: Service & eb: Action elements Message Type Ping: Are you Alive? Pong: Obviously! 168493: XML and Web Services (II/2546) 15

MSH Service #2: What happened to my Message? Query Status Application MSH Node Application Report Status Eb: Service & eb: Action elements Message Type Query: MSH Ack received; no business response Report: Message undelivered or Response lost 168493: XML and Web Services (II/2546) 16

Reliable Messaging n n n Reliability is achieved by a Receiving MSH responding to a message with an Acknowledgment message The receiving party should receive the message once and only once It should be able to withstand n n System failure Network failure 168493: XML and Web Services (II/2546) 17

Reliable Messaging n n A MSH that supports Reliable Messaging MUST keep messages that are sent or received reliably in persistent storage What is a persistent storage? n n The storage in which data is still there after a system failure or interruption Things to be maintained in persistent storage n n Message. Id Complete message (recommendation) Time the message was received Complete response message 168493: XML and Web Services (II/2546) 18

Resending Unacknowledged Messages Party A Application Party A MSH Party B Application Data Message Acknowledgment Data Ack. lost Msg. lost Message Acknowledgment Ignore Duplicate 168493: XML and Web Services (II/2546) 19