HPE OneView supports asynchronous messaging to notify subscribers of changes to managed resources—both logical and physical – and changes to metrics on managed resources. For example, you can program applications to receive notifications when new server hardware is added to the managed environment or when the health status of physical resources changes, and you can stream power, thermal and CPU metrics for managed resources. Using HPE OneView REST APIs, you can obtain certificates to access the two message buses described in this chapter: the State-Change Message Bus or the Metric Streaming Message Bus.

The message content is sent in JSON (JavaScript Object Notation) format and includes the resource model.

Before you can set up subscription to messages, you must create and download an AMQP (Advanced Message Queuing Protocol ) client certificate from the appliance using REST APIs. Next, you connect to the message bus using an AMQP client configured for certificate-based authentication and the TLS 1.1 or TLS 1.2 protocol. After connecting to the message bus, you set up a queue with the queue name empty, and AMQP generates a unique queue name. You use this queue name to bind your client to exchanges and receive messages.

Examples are provided in the following sections, using .NET/C#, Java, and Python to connect to and receive messages from these messages buses.