As a user, I want to be notified of new data available in the Unity Data System

[mike-gangl]

Data availability can:

• trigger a data processing workflow
• be added to a queue for user download
• added for a latency report
• alert the operators to errors

The point here isn't to pre-determine why a user needs this, but to allow missions specific development to use the information. this could be as simple as a CNM message sent to an sns topic. I think we need to determine what metadata is necessary in the message, and what message level metadata is required to do better 'subscriptions'.

There is a larger idea here that might affect operations as well- a message topic for all processing, ingest activity (including errors, and successes). The above scenarios are really special cases where the ingestion was successful, but is a good 'start'. We should loop in SPS, AS, and CS to determine where this 'plumbing' lives and how its used.

[wphyojpl]

After Custom Data Search PR, there is this SNS Topic to subscribe new registered granules to Cumulus.

UDS subscribes to that, and the granule metadata is transformed to STAC + store into UDS specific Elasticsearch.
That UDS script can send another SNS for users to subscribe with complete STAC format.

It can also be sent with only granule ID since the subscriptions can use UDS REST API to get the complete STAC.