Runtime Operations

Mailer runs inside one Go process. There is no job server or distributed cluster runtime yet.

Local execution

Today, workflow source files are local files:

go run ./cmd/mailer-workflow --file examples/workflows/order-totals.yaml

The CLI reads the workflow from disk, compiles it in-process, and executes it in the same process.

Data directories

Use --data-dir or workflow env fields to control state and checkpoint locations.

go run ./cmd/mailer-workflow \
  --file workflow.yaml \
  --data-dir ./data

Two workflows with different names derive isolated state directories under the same base directory.

Graceful shutdown

On context cancellation:

1. The source stops producing.
2. In-flight records drain through the stages.
3. Checkpointing can save a final barrier.
4. The sink drains.
5. If drain exceeds the shutdown timeout, stages are force-aborted.

Production guidance

• Use stable workflow names for stateful jobs.
• Store checkpoint and Pebble directories on persistent local disks.
• Use txnKafka only with stable transactional ids.
• Monitor edge queue sizes to find bottlenecks.
• Use --dry-run --describe before running service-backed workflow changes.