Used by workers to get an ActivityTask from the specified activity
taskList
. This initiates a long poll, where the service holds the HTTP
connection open and responds as soon as a task becomes available. The
maximum time the service holds on to the request before responding is 60
seconds. If no task is available within 60 seconds, the poll returns an
empty result. An empty result, in this context, means that an
ActivityTask is returned, but that the value of taskToken is an empty
string. If a task is returned, the worker should use its type to
identify and process it correctly.
swf_poll_for_activity_task(domain, taskList, identity)
[required] The name of the domain that contains the task lists being polled.
[required] Specifies the task list to poll for activity tasks.
The specified string must not start or end with whitespace. It must not
contain a :
(colon), /
(slash), |
(vertical bar), or any control
characters (U+0000`-`U+001f
\| U+007f`-`U+009f
). Also, it must not be
the literal string arn
.
Identity of the worker making the request, recorded in the
ActivityTaskStarted
event in the workflow history. This enables
diagnostic tracing when problems arise. The form of this identity is
user defined.
svc$poll_for_activity_task( domain = "string", taskList = list( name = "string" ), identity = "string" )
Workers should set their client side socket timeout to at least 70 seconds (10 seconds higher than the maximum time service may hold the poll request).
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.