subflow

Specifies a subflow for a flow, task, or another subflow.

Schema¶

YAML

tasks: List[task | subflow]

Properties¶

Property	Type	Description	References
`name`	`str`	Name of the task.
`conditions`	`executionConditions \| None`	Conditions for execution of the task.	executionConditions
`retry`	`retryStrategy \| None`	Task failure retry strategy.	retryStrategy
`batch_group`	`str \| None`	Name of the batch group that the task should use.
`tasks`	`List[task \| subflow]`	List of tasks to be executed within the subflow.	task, subflow
`dependencies`	`List[str] \| None`	List of task dependencies.

Remarks¶

The batch_group property must be either empty or reference one of the batch groups defined by the flow via the flow.batch_groups property. If it is not specified, the subflow will be:

run for each qubit separately if it is specified in the flow.stages.experiments.qubits,
run once if it is specified elsewhere.

The batch groups that a subflow references must be defined in the flow.batch_groups property.

Examples¶

At its core, a subflow can be used to simply group tasks together. For instance, if you have the following measurements to perform:

a T₁ measurement, defined in t1.ipynb,
a T₂ echo measurement, defined in t2-echo.ipynb,
a T₂* measurement, defined in t2-star-ramsey.ipynb,

you can group them all in a subflow called t-measurements:

name: t-measurements
tasks:
  - name: t1
  - name: t2-echo
    dependencies: 
      - t1
  - name: t2-star-ramsey
    dependencies:
      - t2-echo

Conditional execution¶

Subflows can be used to group tasks that share the same conditions for conditional execution. Continuing with the subflow from the previous example, you might want to use a skip-t-measurements flag to skip the t-measurements subflow. To do this, you can specify the conditions property of the subflow:

name: t-measurements
conditions:
  skip_on_flags:
    - skip-t-measurements
tasks:
  - name: t1
  - name: t2-echo
    dependencies: 
      - t1
  - name: t2-star-ramsey
    dependencies:
      - t2-echo

Timeout and retry¶

Similar to single tasks, a subflow can specify its retry strategy, in which case it applies to the entire subflow as a whole. For instance, if you want a subflow to be retried at least 3 times after a failure (for a total of 4 attempts at executing it), you can do so with the following:

name: t-measurements
retry:
  limit: 3
tasks:
  - name: t1
  - name: t2-echo
    dependencies: 
      - t1
  - name: t2-star-ramsey
    dependencies:
      - t2-echo

Parallel execution using batch groups¶

If you are running a subflow in the experiments.qubits stage, you can specify batch groups for the subflow as a whole. For instance, if you have a batch group called parallel-qubits defined in the flow, you can apply it to the subflow as a whole by using the batch_group property:

name: t-measurements
batch_group: parallel-qubits
tasks:
  - name: t1
  - name: t2-echo
    dependencies: 
      - t1
  - name: t2-star-ramsey
    dependencies:
      - t2-echo