Skip to main content

​
prefect.server.services.db_vacuum

The database vacuum service. Periodically schedules cleanup tasks for old flow runs and orphaned resources (logs, artifacts, artifact collections) past a configurable retention period. A single perpetual service (schedule_vacuum_tasks) enqueues one docket task per resource type on each cycle. Each task runs independently with its own error isolation and docket-managed retries. Deterministic keys prevent duplicate tasks from accumulating if a cycle overlaps with in-progress work.

​
Functions

​
schedule_vacuum_tasks 

schedule_vacuum_tasks(docket: Docket = CurrentDocket(), perpetual: Perpetual = Perpetual(automatic=False, every=timedelta(seconds=get_current_settings().server.services.db_vacuum.loop_seconds))) -> None
Schedule independent cleanup tasks for each resource type. Each task is enqueued with a deterministic key so that overlapping cycles (e.g. when cleanup takes longer than loop_seconds) naturally deduplicate instead of piling up redundant work.

​
vacuum_orphaned_logs 

vacuum_orphaned_logs() -> None
Delete logs whose flow_run_id references a non-existent flow run.

​
vacuum_orphaned_artifacts 

vacuum_orphaned_artifacts() -> None
Delete artifacts whose flow_run_id references a non-existent flow run.

​
vacuum_stale_artifact_collections 

vacuum_stale_artifact_collections() -> None
Reconcile artifact collections whose latest_id points to a deleted artifact. Re-points to the next latest version if one exists, otherwise deletes the collection row.

​
vacuum_old_flow_runs 

vacuum_old_flow_runs() -> None
Delete old top-level terminal flow runs past the retention period.