Book Image

Microsoft Windows Server AppFabric Cookbook

Book Image

Microsoft Windows Server AppFabric Cookbook

Overview of this book

Windows Server AppFabric provides a set of integrated capabilities that extend IIS and the Windows Server platform making it easier to build, scale and manage composite applications today. Windows Server AppFabric delivers the first wave of innovation within an exciting new middleware paradigm which brings performance, scalability and enhanced management capabilities to the platform for applications built on the .NET Framework using Windows Communication Foundation and Windows Workflow Foundation.'Microsoft Windows Server AppFabric Cookbook' shows you how to get the most from WCF and WF services using Windows Server AppFabric leveraging the capabilities for building composite solutions on the .NET platform. Packed with over 60 task-based and immediately reusable recipes, 'Microsoft Windows Server AppFabric Cookbook' starts by showing you how to set up your development environment to start using Windows Server AppFabric quickly. The book then moves on to provide comprehensive coverage of the most important capabilities provided by Windows Server AppFabric, diving right in to hands-on topics such as deploying WCF and WF applications to Windows Server AppFabric and leveraging the distributed caching, scalable hosting, persistence, monitoring and management capabilities that Windows Server AppFabric has to offer, with recipes covering a full spectrum of complexity from simple to intermediate and advanced.
Table of Contents (16 chapters)
Microsoft Windows Server AppFabric Cookbook
Credits
Foreword
About the Authors
About the Reviewers
www.PacktPub.com
Preface

Programmatically controlling persisted workflow instances


Along with Instance Query, Windows Server AppFabric also provides a default implementation of Instance Control Provider API for SQL Workflow Instance Store.

Instance Control commands are defined as a CommandType enumeration, as shown in the following code snippet:

public enum CommandType
{
Suspend,
Resume,
Terminate,
Cancel,
Delete,
}

Instance Control Provider provides an asynchronous and durable command execution mechanism. All the issued commands are stored in a command queue in an Instance Store. Workflow Management Service (WMS) owns the execution of these commands by picking them up from the Instance Store and executing them against the specified workflow instance, following the First-In-First-Out (FIFO) algorithm.

WMS places a lock for 65 seconds on the instance for which it has picked up a command. If the command is executed successfully, it gets deleted from the queue and the lock is released immediately. In case of a failure...