A GCP PubSub Publisher agent interacts with GCP PubSub service to create messages containing data and send a request to the service to publish the messages to the subscribed topic. In a real-time manner, the Publisher allows the submission using the high-performance streaming API. Each messages are submitted through the API which will then deliver them according to the batch configurations. 

When using a client library such as Java, the transmission details can be configured to wrap messages in batch for delivery based on the numbers, byte size or time,  and options to use blocking or non-blocking calls for publishing. If non-blocking calls (e.g. asynchronous) are used, you can specify the flow control and retry settings. While callbacks are also available for client library to report if messages have been accepted by the PubSub service.

GCP PubSub Publisher agent is available as a forwarding agent in Real-Time workflows.

This section contains the following subsections:

• GCP Publisher Agent Configuration(4.3)
• GCP Publisher Agent Events(4.3)
• GCP PubSub Publisher Agent Input/Output Data and MIM(4.3)
• GCP PubSub Publisher Agent Transaction Behaviour(4.3)