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Persistence Configuration

The AppFabric Configuration Wizard lets you perform the following tasks. The AppFabric Windows PowerShell cmdlets also let you create and initialize a SQL Server persistence store. In addition, the cmdlets let you remove all persistence-related artifacts from a SQL Server persistence store.

  • Specify the user account under which the Workflow Management Service runs.

  • Create and initialize a persistence store. The creation process creates the instance store itself and the initialization process creates all the persistence-related artifacts in the persistence store.

  • Register a persistence store in the root Web.config file, which all the applications and services can inherit.

The IIS Manager extensions and Windows PowerShell cmdlets that AppFabric includes let you configure persistence features for workflow services. The following list describes some of these tasks:

  • Enable or disable persistence for workflow services.

  • Specify the SQL Server persistence store that you want to use.

  • Specify whether a SQL Server persistence provider should encode instance state information by using the GZip algorithm before it stores the information in the persistence database.

  • Specify whether the state information for an instance is deleted after the instance is completed.

  • Specify what action should be taken when a host receives an InstanceLockedException. A workflow host receives an InstanceLockedException when it tries to lock an instance because the instance is currently locked by another host. The options allowed for this field are as follows: None, Basic Retry, and Aggressive Retry. The default value is None. The following list provides the descriptions for these three options:

    • None. The service host does not attempt to lock the instance and passes the InstanceLockedException to the caller.

    • Basic Retry. The service host reattempts to lock the instance with an exponentially increasing delay and passes the InstanceLockedException to the caller at the end of the sequence.

    • Aggressive Retry. The service host reattempts to lock the instance with a linear retry interval and passes the exception to the caller at the end of the sequence.

  • Specify the time interval within which the lock must be renewed. The lock expires 30 seconds + (specified lock renewal time) after the lock was renewed the last time.

  • Specifies the time period after which the SQL Workflow Instance Store runs a detection task to detect any runnable or activatable workflow instances in the database after the previous detection cycle. The SQL Workflow Instance Store runs an internal task that periodically wakes up and detects runnable or activatable instances in the persistence database.

The AppFabric Hosting Services include the Workflow Management Service, a Windows service that provides management services for workflow service instances. For more information about this service, see Workflow Management Service. This service does not expose any configuration parameter that can be configured by using extensions or Windows PowerShell cmdlets. However, you can directly configure instance stores that the Workflow Management Service monitors in configuration files.

For details about how to configure persistence features for workflow services, see Configuring Workflow Persistence.

  2012-09-12