Appendix E: Integrating with Existing Enterprise System Management : vCloud Director Notifications and Blocking Tasks Messages : Message Publication
   
Message Publication
The system administrator can configure vCloud Director to enable the publication of messages for all event notifications and/or for specific blocking tasks:
*The notifications indicate the new state of the corresponding vCloud Director entity and are published upon user-initiated events (for example, creation, deployment, and deletion of a vApp) and system-initiated events (for example, vApp lease expiration).
*The blocking tasks suspend long-running operations started as tasks before publishing messages and wait until a system administrator takes action.
The message publication is enabled both for operations started in the vCloud Director UI and the vCloud API, either of which can be used to act upon a message.
The notification messages are published to an Advanced Message Queuing Protocol (AMQP) exchange (AMQP version 0.9.1 supported by RabbitMQ version 2.0 and later).