Change Discovery stream "termination"

[mattmcgrattan]

We (Digirati) have some use cases for Change Discovery where we know that there will be a stream of events happening to IIIF resources that we will want to publish as activities, but where we also know that after a certain point, no more new activities will be added.

For example, we might have a stream that contains the outputs of a crowdsourcing project, or of some automated enrichment process, where we expect the data to change and new manifests to be added as they get processed, but at a certain point, nothing will change again because all of the items have been enriched, or because the crowdsourcing project has ended.

While there's no harm for a consumer of this stream to keep polling the stream, this polling is redundant.

Is there any utility in letting consumers know? This is almost like the inverse of a refresh or bootstrapping event, where the refresh tells a crawler that no events before this point need to be processed, but in this case, it's an indication that no more events after this point need to be processed.

[azaroth42]

Propose transfer to iiif/api