Take Action on a Blocking Task

The BlockingTask element includes links that you can use to take action on a blocking task.

A BlockingTask element is primarily a collection of Link elements that allow you to take action on the task. When a user requests an operation that is configured to create a blocking task, the system sends a message about the task to the configured AMQP broker, and also creates a reference to the task in the cloud's BlockingTaskReferences container. A system administrator can retrieve the list of BlockingTask elements by making a GET request to the system's extension/blockingTasks link. See Monitor Blocking Tasks.

After authenticating to the cloud as a system administrator, the AMQP client can retrieve a blocking task. The AMQP client makes a GET request to a URL that the task creates by appending the value of the id attribute of the task to the entityResolver URL in the Notification. See Example: Notification Message Format.

The following actions are allowed:

resume	Unblock the task and allow it to continue.
abort	End the task, cleaning up any transient objects that it created. Task status is set to ABORTED.
fail	End the task, setting the status of any transient objects that it created to ERROR. Task status is set to ERROR.
updateProgress	Reset the timeout value and timeout action for an active task. Use this action to keep the task alive when it might become subject to a timeout action.

Prerequisites

This operation is restricted to system administrators.

Procedure

Retrieve the list of active blocking tasks.

See Monitor Blocking Tasks. If you are using an AMQP client to handle blocking tasks, skip this step. Each blocking task creates its own AMQP message, which contains a reference to the BlockingTask.

Retrieve an individual BlockingTask.

See the request portion of Example: Handling a Blocking Task.

Make a request.

Action	Request
resume	POST a BlockingTaskOperationParams element to the Link where rel="resume"
abort	POST a BlockingTaskOperationParams element to the Link where rel="abort"
fail	POST a BlockingTaskOperationParams element to the Link where rel="fail"
updateProgress	POST a BlockingTaskUpdateProgressParams element to the Link where rel="updateProgress"

Example: Handling a Blocking Task

This request shows how to retrieve a blocking task without using an AMQP client. Example: Notification Message Format shows how to retrieve the same task using information in the AMQP message.

Request:

GET https://vcloud.example.com/api/admin/extension/blockingTask/25

Response:

200 OK
Content-Type: application/vnd.vmware.admin.blockingTask+xml
...
<vmext:BlockingTask
   xmlns:vmext="http://www.vmware.com/vcloud/extension/v1.5"
   xmlns:vcloud="http://www.vmware.com/vcloud/v1.5"
   status="active"
   timeoutDate="2011-05-07T16:25:18.857+03:00"
   timeoutAction="abort"
   createdTime="2011-05-02T16:25:18.857+03:00"
   name="importSingletonTemplate"
   id="urn:vcloud:blockingTask:25"
   type="application/vnd.vmware.admin.blockingTask+xml"
   href="https://vcloud.example.com/api/admin/extension/blockingTask/25">
   <vcloud:Link
      rel="resume"
      type="application/vnd.vmware.admin.blockingTaskOperationParams+xml"
      href="https://vcloud.example.com/api/admin/extension/blockingTask/25/action/resume" />
   <vcloud:Link
      rel="abort"
      type="application/vnd.vmware.admin.blockingTaskOperationParams+xml"
      href="https://vcloud.example.com/api/admin/extension/blockingTask/25/action/abort" />
   <vcloud:Link
      rel="fail"
      type="application/vnd.vmware.admin.blockingTaskOperationParams+xml"
      href="https://vcloud.example.com/api/admin/extension/blockingTask/25/action/fail" />
   <vcloud:Link
      rel="updateProgress"
      type="application/vnd.vmware.admin.BlockingTaskUpdateProgressOperationParams+xml"
      href="https://vcloud.example.com/api/admin/extension/blockingTask/25/action/updateProgress" />
   <vcloud:Link
      rel="up"
      type="application/vnd.vmware.vcloud.task+xml"
      href="https://vcloud.example.com/api/task/42" />
   <vcloud:Organization
      type="application/vnd.vmware.admin.organization+xml"
      name="example"
      href="https://vcloud.example.com/api/admin/org/97" />
   <vcloud:User
      type="application/vnd.vmware.admin.user+xml"
      name="system"
      href="https://vcloud.example.com/api/admin/user/80" />
   <vcloud:TaskOwner
      type="application/vnd.vmware.vcloud.vAppTemplate+xml"
      name=""
      href="https://vcloud.example.com/api/vAppTemplate/vappTemplate-89" />
</vmext:BlockingTask>

The following request allows the task to resume with a message indicating administrative approval.

POST https://vcloud.example.com/api/admin/extension/blockingTask/25/action/resume
Content-Type: application/vnd.vmware.admin.blockingTaskOperationParams+xml
...
<?xml version="1.0" encoding="UTF-8"?>
<BlockingTaskOperationParams
   xmlns="http://www.vmware.com/vcloud/extension/v1.5" >
   <Message>Approved by system administrator.</Message>
</BlockingTaskOperationParams>