PollForDecisionTaskRequest Class | AWS SDK for .NET V3

Container for the parameters to the PollForDecisionTask operation. Used by deciders to get a DecisionTask from the specified decision taskList. A decision task may be returned for any open workflow execution that is using the specified task list. The task includes a paginated view of the history of the workflow execution. The decider should use the workflow type and the history to determine how to properly handle the task.

This action initiates a long poll, where the service holds the HTTP connection open and responds as soon a task becomes available. If no decision task is available in the specified task list before the timeout of 60 seconds expires, an empty result is returned. An empty result, in this context, means that a DecisionTask is returned, but that the value of taskToken is an empty string.

Deciders should set their client side socket timeout to at least 70 seconds (10 seconds higher than the timeout).

Because the number of workflow history events for a single workflow execution might be very large, the result returned might be split up across a number of pages. To retrieve subsequent pages, make additional calls to PollForDecisionTask using the nextPageToken returned by the initial call. Note that you do not call GetWorkflowExecutionHistory with this nextPageToken. Instead, call PollForDecisionTask again.

Access Control

You can use IAM policies to control this action's access to Amazon SWF resources as follows:

Use a Resource element with the domain name to limit the action to only specified domains.
Use an Action element to allow or deny permission to call this action.
Constrain the taskList.name parameter by using a Condition element with the swf:taskList.name key to allow the action to access only certain task lists.

If the caller doesn't have sufficient permissions to invoke the action, or the parameter values fall outside the specified constraints, the action fails. The associated event attribute's cause parameter is set to OPERATION_NOT_PERMITTED. For details and example IAM policies, see Using IAM to Manage Access to Amazon SWF Workflows in the Amazon SWF Developer Guide.

Inheritance Hierarchy

System.Object
  Amazon.Runtime.AmazonWebServiceRequest
    Amazon.SimpleWorkflow.AmazonSimpleWorkflowRequest
      Amazon.SimpleWorkflow.Model.PollForDecisionTaskRequest

Namespace: Amazon.SimpleWorkflow.Model
Assembly: AWSSDK.SimpleWorkflow.dll
Version: 3.x.y.z

Syntax

public class PollForDecisionTaskRequest : AmazonSimpleWorkflowRequest
         IAmazonWebServiceRequest

The PollForDecisionTaskRequest type exposes the following members

Constructors

	Name	Description
	PollForDecisionTaskRequest()

Properties

Name	Type	Description
Domain	System.String	Gets and sets the property Domain. The name of the domain containing the task lists to poll.
Identity	System.String	Gets and sets the property Identity. Identity of the decider making the request, which is recorded in the DecisionTaskStarted event in the workflow history. This enables diagnostic tracing when problems arise. The form of this identity is user defined.
MaximumPageSize	System.Int32	Gets and sets the property MaximumPageSize. The maximum number of results that are returned per call. Use `nextPageToken` to obtain further pages of results. This is an upper limit only; the actual number of results returned per call may be fewer than the specified maximum.
NextPageToken	System.String	Gets and sets the property NextPageToken. If `NextPageToken` is returned there are more results available. The value of `NextPageToken` is a unique pagination token for each page. Make the call again using the returned token to retrieve the next page. Keep all other arguments unchanged. Each pagination token expires after 24 hours. Using an expired pagination token will return a `400` error: "`Specified token has exceeded its maximum lifetime`". The configured `maximumPageSize` determines how many results can be returned in a single call. The `nextPageToken` returned by this action cannot be used with GetWorkflowExecutionHistory to get the next page. You must call PollForDecisionTask again (with the `nextPageToken`) to retrieve the next page of history records. Calling PollForDecisionTask with a `nextPageToken` doesn't return a new decision task.
ReverseOrder	System.Boolean	Gets and sets the property ReverseOrder. When set to `true`, returns the events in reverse order. By default the results are returned in ascending order of the `eventTimestamp` of the events.
StartAtPreviousStartedEvent	System.Boolean	Gets and sets the property StartAtPreviousStartedEvent. When set to `true`, returns the events with `eventTimestamp` greater than or equal to `eventTimestamp` of the most recent `DecisionTaskStarted` event. By default, this parameter is set to `false`.
TaskList	Amazon.SimpleWorkflow.Model.TaskList	Gets and sets the property TaskList. Specifies the task list to poll for decision tasks. The specified string must not contain a `:` (colon), `/` (slash), `\|` (vertical bar), or any control characters (`\u0000-\u001f` \| `\u007f-\u009f`). Also, it must not be the literal string `arn`.

Version Information

.NET:
Supported in: 8.0 and newer, Core 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.5 and newer, 3.5