Types of Services

The following services will be provided:

Querying Through Services

Allow users to browse and search repositories (these queries are against Metadata Service). Query by:

Allow users to retrieve image datasets (this goes to Image Cutout Service or Mosaic Service):

Allow users to retrieve catalog information (this goes to Qserv):

Allow users to browse history of queries they run in the past, rerun queries from that list.

Allow users to generate output (images, tables) and treat it as input for next query.

Allow users to upload a list of "things" to workspace, then request "repeat a given query for each "thing" from the uploaded list". Example of "things": ra/dec points, ra/dec points + distances, object ids, object names, bounding boxes, etc. In IPAC terminology, this is called "table upload queries". Note, we will need to assign some sort of unique id to such list. Results must contain information which result correspond to which "thing". E.g, if user asks for neighbors near (1,1), (4,4), it is not enough to just return list of neighbors, we need to tell which neighbor is for which point. (related epics: DM-1556 for Qserv, DM-1557 for ImgServ)

Submitting query from SUI – typical scenario:

Note that SUI will facilitate rerunning past queries easily. Metadata Store will contain information about availability of results from queries recently executed, which can be used by SUI to return result without rerunning the query, if results are available. Note, it can get tricky with L1, as "latest" is a moving target.

Returning Results from Services

Output should be delivered in a variety of data formats (even in the short term):

Authentication / Authorization

Access to all services will be controlled. Envisioned modes:

Authentication will be handled through Data Center-provided mechanisms (e.g., provided by NCSA for the main Data Archive Center).

Single-sign-on system would be ideal, especially for users coming from SUI: upon successful authentication (through a cookie or whatever) appropriate mysql-credentials associated with given user will be fetched and used. Note, it can be hard to implement for direct database API connections, it is more feasible if access occurs through wrapped, LSST-provided APIs.

Every science user should have MySQL credentials.

Relevant Off-the-shelf Systems


FERMI Data Catalog