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. - Use a Condition element with the
swf:taskList.name
key to allow the action to access only certain task lists.
If the caller does not have sufficient permissions to invoke the action, or the parameter
values fall outside the specified constraints, the action fails by throwing
OperationNotPermitted
. For details and example IAM policies, see Using IAM to
Manage Access to Amazon SWF Workflows.
Access
public
Parameters
Parameter |
Type |
Required |
Description |
---|---|---|---|
|
Optional |
An associative array of parameters that can have the following keys:
|
Returns
Type |
Description |
---|---|
A |
Source
Method defined in services/swf.class.php | Toggle source view (6 lines) | View on GitHub