Workflow Manager 1.0 Timer Activities


Updated: July 12, 2012

Workflow Manager 1.0 provides support for durable timers, wherein a workflow instance can wait for a certain amount of time or a particular point in time before resuming its execution. This topic provides an overview of the timer activities available in Workflow Manager 1.0.

Delay activities in Workflow Manager 1.0 are useful for scenarios such as a retry loop with a delay before each attempt, or ensuring that a particular set of activities complete before a deadline. If all other branches of execution in the workflow are also waiting, the workflow instance will be persisted to await the expiration of the timer. Two timer variants are supported. A timer can be specified as expiring after a certain interval of time elapses, using the Delay activity, or when a specific date and time is reached, using the DelayUntil activity.

For more information about Workflow Manager 1.0 activities for working with dates and times, see Date Support Activities.

Delay Activity

To delay for a certain amount of time, as defined by a TimeSpan, workflow authors can leverage the System.Activities.Statements.Delay activity. The interval defined by the TimeSpan begins to elapse when the Delay activity begins execution.

System_CAPS_ICON_note.jpg Note

The Delay activity is part of the .NET Framework in the System.Activities.Statements namespace.

DelayUntil Activity

To delay until a particular point in time, as defined by a DateTime, workflow authors can leverage the DelayUntil activity. When the DelayUntil activity begins execution, it delays until the specified date and time are reached. If the date and time specified have already occurred when the DelayUntil activity starts, then the DelayUntil activity immediately completes, and does not generate an idle event.

System_CAPS_ICON_note.jpg Note

The DateTime used by the DelayUntil is specified in UTC time.

System_CAPS_ICON_note.jpg Note

The DelayUntil was introduced with Workflow Manager 1.0 and is in the Microsoft.Activities.Expressions namespace.

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