3. Triggering Workflows with vCloud Notifications : 3.6 Triggered Workflow Examples : 3.6.1 Example of a Workflow Approval: Approve vApp (Simple) : 3.6.1.2. Error Handling
   
3.6.1.2. Error Handling
Avoid a looping situation where the triggered workflow generates a message that triggers the workflow again. There are different techniques for avoiding this problem:
*The workflow might have started the vCloud operation using a different user, so the triggered workflow should resume the blocking task when the user configured for vCenter Orchestrator in vCloud Director is used.
*Use metadata to set a defined key value pair on the task that should be resumed if blocked, and check incoming tasks for it.
The package also contains a helper category that contains the following useful workflows:
*Abort, fail, or resume all blocking tasks – Allows unblocking all tasks for a given vCloud Director host at the same time.
*Remove all AMQP brokersRemove all brokers that have been added in the vCenter Orchestrator inventory.
*Remove a vCloud Director notification subscriptionDelete a subscription and all of its queues.