Backburner jobs can sometimes require that large amounts of auxiliary data be transferred to the render node. For example, jobs can have setups or LUTs that are needed by the render node for correct processing. You can use the job node details and xmlDetails metadata streams to submit smaller amounts of custom text or XML-based data, but for sending larger amounts of data including binary data as attachments, use the Wiretap stream API.
The stream API provides a high-bandwidth out-of-phase connection to the Backburner Manager. The connection does not block concurrent metadata or node hierarchy requests. You can gain access to the stream API using the pushStream method on the WireTapServerHandle object for the Backburner Manager node.
Usually, you can store the attachment data in a local file from which the stream API reads the data. To reduce transfer time and storage requirements on the manager and improve scalability, it is recommended that you compress the local file prior to sending.