
poll-for-activity-task
**********************


DESCRIPTION
===========

Used by workers to get an  ActivityTask from the specified activity
"--task-list" . 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 will return 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.

Warning: 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.

* 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 .


SYNOPSIS
========

   aws swf poll-for-activity-task
     --domain <value>
     --task-list <value>
     [--identity <value>]


REQUIRED PARAMETERS
===================

"--domain"  (string)
   The name of the --domain that contains the task lists being polled.

"--task-list"  (structure)
   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 (u0000-u001f | u007f - u009f). Also, it must not
   contain the literal string arn.

   "name"  (string)

   *Parameter Syntax*

      {
        "name": "string"
      }


OPTIONAL PARAMETERS
===================

"--identity"  (string)
   Identity of the worker making the request, which is recorded in the
   "ActivityTaskStarted" event in the workflow history. This enables
   diagnostic tracing when problems arise. The form of this --identity
   is user defined.
