List all migration subtasks for a workflow

Lists all migration subtasks for a specified migration workflow. Use this to monitor the status of individual steps within a larger BigQuery migration.

Code sample

Node.js

Before trying this sample, follow the Node.js setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Node.js API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

const {MigrationServiceClient} = require('@google-cloud/bigquery-migration').v2;
const {status} = require('@grpc/grpc-js');

const client = new MigrationServiceClient();

/**
 * Lists all migration subtasks for a given workflow.
 *
 * This is useful to track the progress of a migration by by examining its
 * individual steps.
 *
 * @param {string} projectId The Google Cloud project ID (for example, 'example-project-id').
 * @param {string} location The Google Cloud location of the workflow (for example, 'us').
 * @param {string} workflowId The ID of the migration workflow (for example, '12345678-abcd-4372-a567-0e02b2c3d479').
 */
async function listMigrationSubtasks(projectId, location, workflowId) {
  const parent = client.migrationWorkflowPath(projectId, location, workflowId);
  const request = {
    parent,
  };

  try {
    const [subtasks] = await client.listMigrationSubtasks(request);

    if (subtasks.length === 0) {
      console.error(`No subtasks found for workflow ${parent}.`);
      return;
    }

    console.log(`Subtasks for workflow: ${parent}`);
    for (const subtask of subtasks) {
      console.log(`  Subtask Name: ${subtask.name}`);
      console.log(`    Type: ${subtask.type}`);
      console.log(`    State: ${subtask.state}`);
    }
  } catch (err) {
    if (err.code === status.NOT_FOUND) {
      console.error(`Workflow not found: ${parent}`);
    } else {
      console.error('Error listing migration subtasks:', err);
    }
  }
}

Python

Before trying this sample, follow the Python setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Python API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries.

from google.api_core.exceptions import NotFound
from google.cloud import bigquery_migration_v2

client = bigquery_migration_v2.MigrationServiceClient()


def list_migration_subtasks(project_id: str, location: str, workflow_id: str) -> None:
    """Lists migration subtasks for a given workflow.

    Args:
        project_id: The Google Cloud project ID.
        location: The location of the migration workflow, for example, "us".
        workflow_id: The ID of the migration workflow.
    """

    parent = client.migration_workflow_path(project_id, location, workflow_id)

    try:
        print(f"Listing migration subtasks for workflow: {workflow_id}")
        subtasks = client.list_migration_subtasks(parent=parent)
        for subtask in subtasks:
            print(f"  Subtask Name: {subtask.name}")
            print(f"    Type: {subtask.type_}")
            print(f"    State: {subtask.state.name}")
    except NotFound:
        print(f"Migration workflow not found: {parent}")

What's next

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