sqlite-storage.md

SQLite Storage

SQLite durability is optional and disabled by default. The default runtime path does not require SQLite configuration or external storage services.

Enable Storage

task_orchestrator:
  ros__parameters:
    storage:
      enabled: true
      sqlite_path: "/tmp/task_orchestrator.sqlite3"
      retention_days: 30

sqlite3 is part of the Python standard library, so enabling SQLite does not add a runtime package dependency.

Stored Data

• Task records.
• Task events.
• Queued task scheduling fields required for restart recovery.
• Runtime duration and total duration fields.
• Idempotency keys, tracing IDs and fleet-safe context fields.

Query Behavior

When SQLite storage is enabled:

• /task_orchestrator/get_task reads from SQLite when the task is not in the in-memory cache.
• /task_orchestrator/list_task_records reads from SQLite.
• /task_orchestrator/list_events reads from SQLite.
• Both list services support task, source, status, fleet-safe context, tracing and idempotency filters.
• QUEUED task records are recovered on node startup and submitted back through the normal execute-task path.

When storage is disabled, these services use bounded in-memory caches.

Retention

storage.retention_days removes records and events older than the configured age. Set it to 0 to disable retention deletion.