Specifies a decision made by the decider. A decision can be one of these types:
MarkerRecorded event in the history. Markers can be used for adding custom information in the history for instance to let deciders know that they do not need to look at the history beyond the marker event.WorkflowExecutionCompleted event in the history .WorkflowExecutionFailed event in the history.WorkflowExecutionCanceled event in the history.WorkflowExecutionContinuedAsNew event is recorded in the history.TimerStarted event in the history. This timer will fire after the specified delay and record a TimerFired event.TimerCanceled event in the history.SignalExternalWorkflowExecutionInitiated event in the history.RequestCancelExternalWorkflowExecutionInitiated event in the history.StartChildWorkflowExecutionInitiated event in the history. The child workflow execution is a separate workflow execution with its own history.The ordering of decisions should follow a logical flow. Some decisions might not make sense in the current context of the workflow execution and will therefore fail. A decision might also fail due to a limit being reached on your account. One of the following events might be added to the history to indicate an error:
workflowID specified in the decision was incorrect. workflowID specified in the decision was incorrect. The preceding error events might occur due to an error in the decider logic, which might put the workflow execution in an unstable state The cause field in the event structure for the error event indicates the cause of the error.
NOTE: A workflow execution may be closed by the decider by returning one of the following decisions when completing a decision task: CompleteWorkflowExecution, FailWorkflowExecution, CancelWorkflowExecution and ContinueAsNewWorkflowExecution. An UnhandledDecision fault will be returned if a workflow closing decision is specified and a signal or activity event had been added to the history while the decision task was being performed by the decider. Unlike the above situations which are logic issues, this fault is always possible because of race conditions in a distributed system. The right action here is to call RespondDecisionTaskCompleted without any decisions. This would result in another decision task with these new events included in the history. The decider should handle the new events and may decide to close the workflow execution.
You must code a decision by first setting the decision type field to one of the above decision values, and then set the corresponding attributes field shown below:
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