drogna

A demonstration harness. Every number in it is invented.

Version 1 record

This page describes software that has been retired. It is accurate about Version 1 and is not a description of what runs now — see the current site and the archive.

C-08 Coverage store

Status: built

  • Code: stores/coverage/ — layout.md is the normative convention and validate_layout.py enforces it; the files are written by services/publisher/ and read through query/plugins/coverage_catalogue.py and services/monitor/src/harness_monitor/coverage.py
  • Delivered by: specs/008-query-layer, with the writing half in specs/009-control-loop
  • Covered by: tests/unit/test_coverage_catalogue.py, tests/integration/test_coverage_store_seam.py and tests/integration/test_new_run_servable.py, which publishes a run and asserts it is servable with no configuration edit
  • Not present: the run manifest's shape is stated normatively in layout.md and enforced by code, but it has no master under contracts/schemas/ as a generated-types source, which is why the shape is written down twice — in the publisher that writes it and the catalogue that reads it. layout.md records this as an outstanding gap

Responsibility: gridded forecast and uncertainty fields.

What it does

It holds model output: gridded forecast fields and the matching uncertainty fields, written as NetCDF following the CF conventions. One model run produces one set of files; the store keeps several runs and knows which is current.

The cataloguing convention

The requirement that shapes this component is that a new model run must become servable without editing collection configuration. The naming and directory convention has to carry enough information — run identifier, valid time, variable — for the query layer to discover a new run rather than be told about it.

This sounds like a filing preference and is actually the difference between a control loop that closes and one that needs a human in it. If publishing a run requires a configuration edit, the sense → decide → act → publish cycle stops at "act" and waits.

Why the output is a port

NetCDF today, Zarr plausibly later. This is one of the four boundaries drogna is willing to call a genuine port, because a second implementation is actually conceivable rather than theoretically conceivable. The bespoke trajectory provider described under the query layer sits behind this same port.

Requirements: FR-21, FR-29, FR-30. Feature: 008.