Axis2, Middleware for Next Generation Web Services Srinath Perera

Next 20 Minutes Why Axis2? What does it have? Architecture Core Concepts XML processing Extensibility Messaging Conclusion

Why Axis2?

What does it have?

Architecture

Core Concepts

XML processing

Extensibility

Messaging

Conclusion

Why Axis2? Web Services has changed, so are the values and expectations from WS Middleware Better support for Messaging, Asynchronous interactions Performance, Need for better XML processing Better support for WS-* specifications New specs, and changes to specs (Better or for worse)

Web Services has changed, so are the values and expectations from WS Middleware

Better support for Messaging, Asynchronous interactions

Performance, Need for better XML processing

Better support for WS-* specifications

New specs, and changes to specs

(Better or for worse)

What does it have? Better XML processing model Powerful messaging support Seamless integration with WS-* implementations – WS-Addressing, WS-Security, WS-RM …. Archive based Deployment Close integration with Policy HTTP, TCP, SMTP and JMS transports REST, MTOM, WS-Policy … Pluggable data Binding WSDL based Code Generation

Better XML processing model

Powerful messaging support

Seamless integration with WS-* implementations – WS-Addressing, WS-Security, WS-RM ….

Archive based Deployment

Close integration with Policy

HTTP, TCP, SMTP and JMS transports

REST, MTOM, WS-Policy …

Pluggable data Binding

WSDL based Code Generation

Architecture 10,000 foot view

XML processing Model Major decider of performance Expectations Better performance, Streaming access to the Soap Message Move back and forth Easy accesses to the Soap Message, in other words Tree like (DOM like) representation

Major decider of performance

Expectations

Better performance, Streaming access to the Soap Message

Move back and forth

Easy accesses to the Soap Message, in other words Tree like (DOM like) representation

How to tackle XML Processing? Use of XML streaming API Virtual XML elements, that provide familiar interface to user Underline implementation based on differed/lazy parsing (Data is read as late as possible) Switching back to the pull parser Use cases Streaming at data binding Pass result to another Web Service (Workflows)

Use of XML streaming API

Virtual XML elements, that provide familiar interface to user

Underline implementation based on differed/lazy parsing (Data is read as late as possible)

Switching back to the pull parser

Use cases

Streaming at data binding

Pass result to another Web Service

(Workflows)

Extensibility Support for security, reliability, transactions, addressing …. Axis1 approach, Handler architecture

Support for security, reliability, transactions, addressing ….

Axis1 approach, Handler architecture

Need bit more than Handlers Simpler deployment Automatic configuration e.g. Security What if two or more Handlers co-exists? E.g. Security and Reliable Messaging Operation Injection - e.g. RM, WS-RF, WS-Sec Conversation Managing Handlers automatically and transparently based on Policy

Simpler deployment

Automatic configuration e.g. Security

What if two or more Handlers co-exists? E.g. Security and Reliable Messaging

Operation Injection - e.g. RM, WS-RF, WS-Sec Conversation

Managing Handlers automatically and transparently based on Policy

Axis2 Modules for extensibility Module = Handler(s), + ordering rules + Initialization logic + Operations Archive based deployment, just copy it to Axis2 repository. Available modules vs Engaged modules WS-Policy based engagement and automatic configuration Possibility of automatically adapting services with (dynamic/static) policy negotiation

Module = Handler(s), + ordering rules + Initialization logic + Operations

Archive based deployment, just copy it to Axis2 repository.

Available modules vs Engaged modules

WS-Policy based engagement and automatic configuration

Possibility of automatically adapting services with (dynamic/static) policy negotiation

Messaging Messaging System addresses three issues Complex message groupings and correlation Blocking-Non Blocking behavior of Client /Server API Synchronous and Asynchronous behavior of transports Supports for following cases Request response, non-blocking synchronous Request response, non-blocking asynchronous Request response, blocking synchronous Request response, blocking asynchronous One way

Messaging System addresses three issues

Complex message groupings and correlation

Blocking-Non Blocking behavior of Client /Server API

Synchronous and Asynchronous behavior of transports

Supports for following cases

Request response, non-blocking synchronous

Request response, non-blocking asynchronous

Request response, blocking synchronous

Request response, blocking asynchronous

One way

Messaging in Axis2 Two Pipes, IN and OUT Composing pipes at the Client (MEP clients) and Server (Message Receiver) to yield different MEPS

Two Pipes, IN and OUT

Composing pipes at the Client (MEP clients) and Server (Message Receiver) to yield different MEPS

Messaging (Continued) Three Properties (non-blocking, MEP, Sync-Async) are Handled in Operation Clients and Message receivers Switch between the different modes by simply setting client API parameters If you are a Geek, you may even add new Operation clients/ Message Receivers e.g. Pub-Sub use case

Three Properties (non-blocking, MEP, Sync-Async) are Handled in Operation Clients and Message receivers

Switch between the different modes by simply setting client API parameters

If you are a Geek, you may even add new Operation clients/ Message Receivers

e.g. Pub-Sub use case

Architecture (Revisited)

Summery We discussed rationale for Axis2, and brief looked at the architecture We discuss three main topics, XML Processing, Extending SOAP Processing Model and Messaging For more information Official Site http://ws.apache.org/axis2/ http://www.wso2.net/projects/axis2/java Mailing List http://ws.apache.org/axis2/mail-lists.html

We discussed rationale for Axis2, and brief looked at the architecture

We discuss three main topics, XML Processing, Extending SOAP Processing Model and Messaging

For more information

Official Site http://ws.apache.org/axis2/

http://www.wso2.net/projects/axis2/java

Mailing List

http://ws.apache.org/axis2/mail-lists.html