# Monitoring and running pipelines (/pipelines/monitoring)

See whether your pipelines ran, read their logs, and trigger a run yourself.

Opening **Pipelines** opens the Airflow web interface. A pipeline (Airflow calls
it a **DAG**) is a job that loads data into tables — see [authoring pipelines](/pipelines/authoring).
Visibility is fleet-wide: if you can open Pipelines, you see **every** pipeline in the deployment, not
a subset. An empty list means none are deployed.

<Callout title="Prerequisite">
  `can_view_pipelines` opens Pipelines and reads runs, logs and code. `can_run_pipelines` adds
  trigger, clear, mark and pause, and implies view. Missing from your sidebar means you hold neither.
</Callout>

Everything below is standard Airflow; the [Airflow UI docs](https://airflow.apache.org/docs/apache-airflow/stable/)
cover each screen.

## What to look at

- **Pipeline list** — the landing screen: every pipeline with its recent runs, schedule, and paused state.
- **Runs** — select a pipeline for its run history; each run has a state (success, running, failed) and start time.
- **Task states** — within a run, each task's state, in a grid and a graph showing dependencies and which task failed.
- **Logs** — open a task instance for the log it wrote. A failed run tells you what went wrong here.

## Operating a run

With `can_run_pipelines` you operate every pipeline in the deployment:

- **Trigger** a run on demand (unpause the pipeline first if it is paused).
- **Clear** a task or run so it runs again.
- **Mark** a task or run as success or failed.
- **Pause** and unpause a pipeline's schedule.

## Stop a runaway pipeline

A run that is taking too long or doing the wrong thing keeps going until you stop it. With
`can_run_pipelines`:

1. **Pause** the pipeline with its toggle, so the scheduler starts no new runs.
2. **Mark** the running run, or its running tasks, as **failed**. Airflow stops the tasks that are
   still running.

Pausing alone does not stop a run that has already started. Two limits also end a task on their own:

- A task that uses more memory than it is allowed is stopped, and fails.
- A task with an `execution_timeout` fails once it runs longer than that. Set one on any task that
  calls an external source; see [authoring pipelines](/pipelines/authoring).

## What needs an administrator

These need `can_admin`:

- **Deleting** a pipeline. This removes its run history irrecoverably.
- Airflow's **Connections**, **Variables**, **Pools**, **Config** and **Backfills**, and changes to
  **Assets**.

Airflow's audit log, users, roles, providers and plugins screens are not available to Databaas users;
people and permissions are managed in the portal, see [managing access](/access/managing-access). A permission
change applies within about ten seconds, without signing in again. If a control is refused, check
what it needs against the
[permissions reference](/access/permissions-reference#where-each-permission-is-enforced).