Level 2 Inversion

See DEVELOPMENT.md

Questions

• Who chooses which OP to process next?
  • do we mark A as "work on this next?"
  • or does Han scan available work and choose?
  • who gets yelled at if something doesn't get done?

Answers

• (Tony) We need local persistence but a new DB may increase the workload for Tony.
  • Build against POSTGRES. Tony will figure it out
  • migrations can work any way
• Han wants to work on OPs, not datasets. How do we know when an OP is complete?
  • OPs do not exist at the metadata level yet
  • Wait a certain number of days for all datasets to appear before assuming it is ready.
• How does L2 data become available to the system?
  • L2 will store OP metadata related to inversions
  • Metadata store will aggregate this information and introduce an OP schema

Service Graph

Arrow indicate the direction of dependency. If A -> B, then A is aware of B and calls it or interacts with it.

graph LR;
    L2[Level 2]
    State[(Internal State)]
    Meta[Metadata Store]
    Globus[GLOBUS]
    Sci[Science / CU Blanca]

    subgraph Level 2
      L2
      L2 --> State
      State
      Sci --> |OPs| L2
      Sci --> |ready event| L2
    end

    Meta --> |OPs| L2
    Portal --> Meta
    L2 --> |datasets| Meta
    Meta --> Globus
    Sci --> |dataset files| Globus

Deployable Containers

• L2 Service
• State Postgres DB - New or existing instance, but L2 accesses unique tables

Process

flowchart LR;
    Scan[[Scan]]
    Qualify[[Qualify]]
    Preprocess[[Preprocess]]
    Invert[[Invert]]
    Publish[[Publish]]

    Scan --> Qualify
    Qualify --> Preprocess
    Preprocess --> Invert
    subgraph Science
      Invert
    end
    Invert --> Publish

Scan - Check the entire metadata store for OP candidates and add to the database if they don't exist. Update if necessary

Qualify - Check criteria for invertibility and record if OPs are invertible or not

Preprocess - Preprocess data if necessary, saving intermediate files if needed (unknown)

Invert - Han's Science Team manually inverts the OP

Publish - Make L2 data available to metadata store / portal

Inversion States

Observing Programs are identified, then pass through the following states. The graph below illustrates a successful flow, but any processing step may fail, putting the OP into an Error state.

stateDiagram-v2
    dis: Discovered
    inv: Invertible
    no: Not Invertible
    pre: Preprocessed
    work: Working
    done: Inverted
    pub: Published
    err: Error

    dis --> inv
    dis --> no
    inv --> pre
    pre --> work
    work --> done: Science
    done --> pub

We record this history of all states, and only add information rather than mutating the record

Definitions

Observing Program - a group of datasets related to a single observation with a measurement in mind, which is a smaller division of a proposal