Polish pass hardening the queue and closing plan gaps.
- Task state machine gains `running`: the first heartbeat moves a task from
leased to running (migrations 0006/0007 add the enum value and extend the
lease-integrity check). verifyLease, ExpireLease, the reaper SQL, and job
progress all treat leased and running alike.
- Worker liveness: a heartbeat from a registered worker (UUID worker_id) bumps
its last_heartbeat_at online; a second background reaper marks workers offline
after WORKER_OFFLINE_AFTER of silence (RunReaper generalized to RunPeriodic).
- Request-size limits: JSON bodies capped at 1 MiB; dataset/artifact uploads
capped at MAX_UPLOAD_BYTES (default 1 GiB) via http.MaxBytesReader.
- Tests cover the running transition, liveness + offline reaper (unit over
memstore and integration over Postgres).
The coordinator can now ingest a dataset itself, not only accept client-supplied
chunk URIs.
- internal/chunk: a deterministic, generic TSV row splitter — repeats the header
per shard, buffers one shard at a time, rejects header-only input. Unit-tested.
- POST /jobs/upload (multipart): streams the dataset into an input artifact,
splits it into shard artifacts, and creates one shard task per shard, all in
one transaction; blobs are cleaned up if the transaction fails.
- GET /tasks/{id}/input streams a task's input shard back to the worker.
- domain: NewUploadedJob, NewShardTask, Task/Job.InputArtifactID; a shard task's
input is an artifact, not a URI. Claim response nests input:{uri,sha256} per
the contract, with uri = /tasks/{id}/input for shards.
- migration 0005 makes input_uri nullable and adds a has-input check.
- The existing URI-based POST /jobs path is untouched; both coexist.
Task results are now coordinator-owned artifacts end to end.
- domain.Task carries ResultArtifactID instead of ResultURI/ResultSHA256;
CompleteWith and its idempotency key are keyed on the artifact id.
- CompleteTask verifies the referenced artifact was stored for this exact
task (rule 10): a worker cannot finish task B with task A's artifact, nor
name an id that isn't a partial_result. Mismatch → 409.
- POST /tasks/{id}/result takes {result:{artifact_id,...}}; ListResults and
ResultManifest follow.
- migration 0004 drops result_uri/result_sha256 and requires a completed task
to reference its result_artifact_id.
- smoke and requests.http exercise upload → complete-by-id → replay → conflict.
Introduce durable, coordinator-owned artifacts — the model the master plan
requires instead of trusting worker-supplied result URIs.
- migration 0003: artifacts table + artifact_kind enum, plus nullable
input/result_artifact_id columns on jobs and tasks.
- domain.Artifact with NewArtifact/SetContent; storage keys derive from a
fresh UUID, never from a client filename (no path traversal).
- BlobStore and ArtifactRepository ports.
- blob.FSStore: filesystem blob storage that streams while hashing (SHA-256),
fsyncs, and atomically renames into place — a failed upload leaves neither a
committed artifact nor a staging file. Covered by unit tests.
- ArtifactRepo (squirrel) and COORDINATOR_STORAGE_DIR config.
HTTP upload/download handlers and the switch of result submission to
artifact_id come in the next parts.
Align the coordinator with the master PLAN.md (CTX-00, CTX-04) and harden
process startup.
- CTX-00: freeze docs/api-contract.md as the v1 source of truth for the
Go coordinator and Python worker.
- CTX-04: worker registry — workers table (migration 0002), domain.Worker,
RegisterWorker use case, WorkerRepository, and POST /workers/register.
- Contract alignment: claim uses `capabilities` (was `workloads`),
COORDINATOR_TOKEN env (WORKER_AUTH_TOKEN kept as fallback), and
GET /health now reports database readiness (503 when the DB is down).
- Logging: logs are teed to stdout and an optional rotated file (LOG_FILE)
via lumberjack, so they survive a container rebuild.
- Startup resilience: the initial DB connection is retried with backoff,
so the coordinator waits for Postgres to boot instead of crash-looping.
Adds the SciMesh coordinator: a durable task-queue server on PostgreSQL
that owns all database access, with workers reaching it over HTTP only.
Structured as a modular monolith following Clean Architecture:
domain entities and their invariants, no I/O
usecase business operations + repository/clock ports
transport HTTP handlers, DTOs, auth, error mapping
storage PostgreSQL repositories, transactions carried in context
infra config, pool, clock, server, lease reaper
Dependencies point strictly inward; domain imports nothing from the module.
Working: layer wiring, routing, shared-token auth, access logging, request
IDs, domain-error to status-code mapping, transactional boundaries,
graceful shutdown (HTTP drain -> reaper stop -> pool close), migrations,
and a Compose stack starting Postgres -> migrations -> coordinator.
The domain is complete and covered by unit tests that need no database:
lease ownership, stale attempts, idempotent result replay, retry budgets,
and lease expiry.
Repository methods are stubs returning ErrNotImplemented (HTTP 501). The
SQL for atomic claiming (FOR UPDATE SKIP LOCKED) and for lease expiry is
written and ready to wire up.
See coordinator/ARCHITECTURE.md for the layer map and a request traced
through every layer.
Emil