6.1 Choreography
This clause defines the mechanism by which a record company or distributor can communicate batches of metadata and the resource files that make up the releases in the batch to a DSP, using:
A cloud-based storage server that is hosted by the record company or distributor;
A cloud-based storage server that is hosted by the DSP; or
A cloud-based storage server that is hosted by a third party.
This specification does not therefore define on whose hardware the files are being stored as this is determined by the bilateral agreement betwee
n the record company or distributor and the DSP.
The choreography of the batch profile is depicted in the diagram in Figure 3, below:
Figure 3 – Batched Choreography
The record company or distributor and the DSP are responsible to ensuring that the communication is secure.
The NewReleaseMessage and the AcknowledgementMessage referenced in Figure 3 are the same as those used in the release-by-release profile.
The structure of the NewReleaseMessages communicated using this batch profile shall follow the release profile agreed as appropriate for the communicated release(s) as defined in Part 2: Release Profiles of the ERN standard.
The file server organisation and file naming conventions for the SFTP batch profile are defined in Clauses 6.3 and 6.4 below.
This part of the ERN standard does not define when the record company or distributor shall start or finish the uploading of the next batch of NewReleaseMessage (including all resource files). Equally, this part of the ERN standard does not define when the DSP shall start or finish its download of the files.
In addition to the exchange shown in the diagram in Figure 3 above, if after ingestion by the DSP it has sent an AcknowledgementMessage reporting FileOK but closer inspection shows deficiencies that were not detected previously the DSP may use the AcknowledgementMessage to communicate different status information.
The recipient of the AcknowledgementMessage may remove that message from the file server after an appropriate and mutually agreed period of time. The default period is one month. The AcknowledgementMessage is defined in this standard.
When a record company or distributor communicates metadata and resource files using the batch profile the trigger to indicate to the DSP that a batch is completely loaded is the additional loading of a ManifestMessage. The structure of the ManifestMessage is set out in the diagram in Figure 4 below and defined in this part of the ERN standard.
Instead of using a ManifestMessage, in exceptional circumstances, such as for the support of human intervention, it is permissible for the record company or distributor to use a zero-byte semaphore file to indicate the upload is complete. The use of such a semaphore file may alert operational users on the DSP's side, indicating the manual nature of the override.
Figure 4 – Structure of ManifestMessage