Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By : Kenneth Scott Allen
Book Image

Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#

By: Kenneth Scott Allen

Overview of this book

Windows Workflow Foundation (WF) is a technology for defining, executing, and managing workflows. It is part of the .NET Framework 3.0 and will be available natively in the Windows Vista operating system. Windows Workflow Foundation might be the most significant piece of middleware to arrive on the Windows platform since COM+ and the Distributed Transaction Coordinator. The difference is, not every application needs a distributed transaction, but nearly every application does have a workflow encoded inside it. In this book, K Scott Allen, author of renowned .NET articles at www.odetocode.com, provides you with all the information needed to develop successful products with Windows Workflow. From the basics of how Windows Workflow can solve the difficult problems inherent in workflow solutions, through authoring workflows in code, learning about the base activity library in Windows Workflow and the different types of workflow provided, and on to building event-driven workflows using state machines, workflow communications, and finally rules and conditions in Windows Workflow, this book will give you the in-depth information you need. Throughout the book, an example "bug reporting" workflow system is developed, showcasing the technology and techniques used.
Table of Contents (14 chapters)
Programming Windows Workflow Foundation: Practical WF Techniques and Examples using XAML and C#
Credits
About the Author
About the Reviewer
Preface

Persistence and Tracking Together


The SQL persistence and SQL tracking services work to provide durable storage for workflow state and workflow tracking information respectively. However, they don't quite work together. Specifically, each service will operate using different connections to the database. A workflow runtime with both services present will use more connections then necessary. Additional overhead will arise if the tracking service is transactional. When transactions span multiple connections, the Microsoft Distributed Transaction Coordinator (MSDTC) becomes involved and manages the transaction. MSDTC carries some overheard.

WF provides an optimization for applications using both the SQL persistence and SQL tracking services with the SharedConnectionWorkflowCommitWorkBatchService class. The service allows the two SQL services to share a connection if the connection string for both is the same.

Shared Connection Configuration

The configuration file below configures both SQL workflow...