This user story is for implementing a new DataLake Exposure Service (DES) MS for the E2E Network Slicing use case. The DES MS shall be accessible only via ONAP internal components (UUI and other DCAE MS in Guilin release). The DES shall expose a REST interface to provide:

• Requested PM, KPI and other data as requested by UUI (Slice Tenant/Operator) for KPI Monitoring, as well as
• PM/KPI data as requested by other DCAE MS - e.g., Slice Analysis MS for Closed Loop Control or Intelligent Slicing

DES MS shall access a MongoDB within ONAP for fetching the required data (using SQL queries), and performing computations if needed, before responding to the requestor. Note that the DB interface from DES can be easily extended to provide access to external Data Lake with minimal impacts, and no impact to other upstream components.

DES MS shall have an admin interface to provision the query mapping rules for fetching the required data from the DB.

Beyond Guilin, if DES needs to be accessed by NB systems, it shall be facilitated by ExtAPI so that DES is not directly exposed to the NB interface.