Book Image

Business Process Execution Language for Web Services 2nd Edition

Book Image

Business Process Execution Language for Web Services 2nd Edition

Overview of this book

Web services provide the basic technical platform required for application interoperability. They do not, however, provide higher level control, such as which web services need to be invoked, which operations should be called and in what sequence. Nor do they provide ways to describe the semantics of interfaces, the workflows, or e-business processes. BPEL is the missing link to assemble and integrate web services into a real business process BPEL4WS standardizes process automation between web services. This applies both within the enterprise, where BPEL4WS is used to integrate previously isolated systems, and between enterprises, where BPEL4WS enables easier and more effective integration with business partners. In providing a standard descriptive structure BPEL4WS enables enterprises to define their business processes during the design phase. Wider business benefits can flow from this through business process optimization, reengineering, and the selection of most appropriate processes . Supported by major vendorsó including BEA, Hewlett-Packard, IBM, Microsoft, Novell, Oracle, SAP, Sun, and othersó BPEL4WS is becoming the accepted standard for business process management. This book provides detailed coverage of BPEL4WS, its syntax, and where, and how, it is used. It begins with an overview of web services, showing both the foundation of, and need for, BPEL. The web services orchestration stack is explained, including standards such as WS-Security, WS-Coordination, WS-Transaction, WS-Addressing, and others. The BPEL language itself is explained in detail, with Code snippets and complete examples illustrating both its syntax and typical construction. Having covered BPEL itself, the book then goes on to show BPEL is used in context. by providing an overview of major BPEL4WS servers. It covers the Oracle BPEL Process Manager and Microsoft BizTalk Server 2004 in detail, and shows how to write BPEL4WS solutions using these servers.
Table of Contents (14 chapters)
Business Process Execution Language for Web Services
Credits
About the Authors
About the Reviewers
Preface
Index

Standard Faults


The following table is a list of standard faults that commonly arise in BPEL execution.

Fault name

Fault is thrown when:

selectionFailure

A selection operation performed in either a function, such as bpws:getVariableData, or an assignment encounters an error.

conflictingReceive

More than one <receive> activity or equivalent (currently <onMessage> branch in a <pick> activity) are enabled simultaneously for the same partner link, port type, operation, and correlation set(s).

conflictingRequest

More than one synchronous inbound request is active on the same partner link for a particular port type, operation. and correlation set(s).

mismatchedAssignmentFailure

Incompatible types are encountered in an assign activity.

joinFailure

Join condition of an activity evaluates to false.

forcedTermination

A fault occurs in an enclosing scope.

correlationViolation

The contents of messages processed in an <invoke>, <receive>, or <reply> activity do not match specified correlation information.

uninitializedVariable

There is an attempt to access the value of an uninitialized part in a message variable.

repeatedCompensation

An installed compensation handler is invoked more than once.

invalidReply

A reply is sent on a partner link, port type, and operation for which the corresponding <receive> with the same correlation has not been carried out.