Book Image

WS-BPEL 2.0 Beginner's Guide

Book Image

WS-BPEL 2.0 Beginner's Guide

Overview of this book

Table of Contents (19 chapters)
WS-BPEL 2.0 Beginner's Guide
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding asynchronous service invocations


Unlike in a synchronous web service invocation, both parties act as client and server during an asynchronous web service invocation. So when sending the request, the BPEL process acts as the client and the external service becomes the server for the particular conversation. Then when the external service sends the response, external service is the client and the BPEL process is the server for that particular conversation.

In contrast with a synchronous web service invocation, those two client-server conversations should be defined separately in an asynchronous web service invocation. Now we will analyze the difference between a synchronous and an asynchronous invocation.

If you consider the implementation of a synchronous process, then you will notice the following facts:

  • In the BPEL process, the <invoke> activity is used for the whole conversation. So it encapsulates the input and output parameters required for the synchronous communication...