Skip to content

Maestro UI user manual

The Maestro user interface (UI) is primarily meant for monitoring the status of workflows. In addition, a few actions are provided in the UI, including invalidating, rerunning or aborting workflows/steps/artefacts.

Note that the Maestro UI is not intended for creating or editing workflows, which should be done through the API.

Main interface

The main interface of Maestro has three main components:

  1. A dashboard for monitoring the status of all workflows.
  2. A list of workflows that have been ordered, sorted by newest on top.
  3. A search box to filter the list of workflows by workflow name or any metadata keyword. To view only the workflows that have failed, click the "Errors only" button next to the search box.

Workflow steps and details

Click on a workflow in the main interface to view its individual steps, and the "Details" button to view the details for a particular step. The resulting modal has separate tabs for input and output artefacts, as well as the standard output and error logs. The last tab, "Action", lets you invalidate or rerun individual steps/artefacts.

Action: Invalidate

Invalidation means that a workflow, workflow step or artefact is removed from further use. This is useful if a step has failed or otherwise produced erroneous results that should not be used downstream. It is also useful if you want to rerun a step that has already been successfully completed, but with different input. For workflow steps and output artefacts, an option to propagate the invalidation to downstream steps is provided.


Invalidating a workflow, workflow step or artefact is a destructive action that cannot be undone. Make sure you are certain that the results are erroneous before invalidating.

Invalidate workflow

Invalidating an entire workflow will remove all artefacts produced by the workflow, as well as all steps. Note that to rerun, a new order must be placed in the API, it is not possible to rerun a workflow directly from the UI.

Note that this action is performed from the main interface, whereas invalidating individual steps or artefacts is done from the details view.

Invalidate workflow step

Invalidating a workflow step will remove all output artefacts produced by the step, as well as the step itself. This is useful if a step has failed and you want to rerun it without having to rerun the entire workflow.

Invalidate artefact

Invalidating an artefact will remove the artefact itself, but not the step that produced it. This is useful if an artefact has been produced erroneously and should not be used downstream.

Note that it is possible to invalidate both input and output artefacts. In the former case, no propagation is possible, as this would produce unpredictable results.

Propagate invalidation

If a step or artefact has produced erroneous results, all downstream steps and artefacts may also be affected. To ensure that all invalid results are removed from further use, choose "Propagate" when invalidating the step or artefact (note: not possible for input artefacts). This will invalidate all downstream steps/artefacts in addition to the one you start with.

Action: Rerun

Rerunning a workflow step will attempt to create new output artefacts from the step. This is useful if a step has failed due to a transient error, and you want to retry it without having to rerun the entire workflow.


Note that only failed or invalidated steps may be rerun, and that rerunning will also affect downstream steps.

Action: Abort

Aborting a pending workflow step can be done in the main interface ("Abort" button"), and will prevent the step from being started. This is useful if you want to stop a workflow that is no longer needed.