Applications

Why Would You Use Applications?

Applications are groupings of assets based on a particular purpose, similar to domains and data products. For more information on what an Application is, and how it differs from other concepts, refer to About DataHub Applications.

Goal Of This Guide

This guide will show you how to

• Create an application.
• Read the application attached to a dataset.
• Add a dataset to an application
• Remove the application from a dataset.

Prerequisites

For this tutorial, you need to deploy DataHub Quickstart and ingest sample data. For detailed steps, please refer to DataHub Quickstart Guide.

Create Application

GraphQL

mutation createApplication {
  createApplication(
    input: {
      properties: {
        name: "My New Application"
        description: "An optional description"
      }
    }
  )
}

If you see the following response, the operation was successful:

{
  "data": {
    "createApplication": "<application_urn>"
  },
  "extensions": {}
}

Python

# Inlined from /metadata-ingestion/examples/library/application_create_full.py
#!/usr/bin/env python3

import os

from datahub.emitter.mce_builder import make_dataset_urn, make_user_urn
from datahub.emitter.mcp import MetadataChangeProposalWrapper
from datahub.emitter.rest_emitter import DatahubRestEmitter
from datahub.metadata.schema_classes import (
    ApplicationPropertiesClass,
    ApplicationsClass,
    DomainsClass,
    GlobalTagsClass,
    OwnerClass,
    OwnershipClass,
    OwnershipTypeClass,
    TagAssociationClass,
)


# Utility function for creating application URNs (not yet in SDK)
def make_application_urn(application_id: str) -> str:
    """Create a DataHub application URN."""
    return f"urn:li:application:{application_id}"


def create_banking_application():
    """Complete example of creating an application and associating entities."""

    # Initialize emitter
    gms_server = os.getenv("DATAHUB_GMS_URL", "http://localhost:8080")
    token = os.getenv("DATAHUB_GMS_TOKEN")
    emitter = DatahubRestEmitter(gms_server=gms_server, token=token)

    try:
        # Create application
        application_urn = make_application_urn("banking-app")

        # 1. Application Properties
        application_properties = ApplicationPropertiesClass(
            name="Banking Application",
            description="Core banking application handling customer accounts and transactions.",
        )

        emitter.emit(
            MetadataChangeProposalWrapper(
                entityUrn=application_urn, aspect=application_properties
            )
        )

        # 2. Ownership
        ownership = OwnershipClass(
            owners=[
                OwnerClass(
                    owner=make_user_urn("john.smith@company.com"),
                    type=OwnershipTypeClass.TECHNICAL_OWNER,
                ),
                OwnerClass(
                    owner=make_user_urn("jane.doe@company.com"),
                    type=OwnershipTypeClass.BUSINESS_OWNER,
                ),
            ]
        )
        emitter.emit(
            MetadataChangeProposalWrapper(entityUrn=application_urn, aspect=ownership)
        )

        # 3. Tags and Domain
        tags = GlobalTagsClass(tags=[TagAssociationClass(tag="urn:li:tag:Production")])
        emitter.emit(
            MetadataChangeProposalWrapper(entityUrn=application_urn, aspect=tags)
        )

        domains = DomainsClass(domains=["urn:li:domain:finance-domain"])
        emitter.emit(
            MetadataChangeProposalWrapper(entityUrn=application_urn, aspect=domains)
        )

        # 4. Associate datasets
        datasets = ["customer_accounts", "transaction_history", "account_balances"]

        for dataset_name in datasets:
            dataset_urn = make_dataset_urn("hive", dataset_name, "PROD")
            applications_aspect = ApplicationsClass(applications=[application_urn])

            emitter.emit(
                MetadataChangeProposalWrapper(
                    entityUrn=dataset_urn, aspect=applications_aspect
                )
            )

        print(f"Successfully created application: {application_urn}")
        print(f"Associated {len(datasets)} datasets with the application")

    finally:
        emitter.close()


if __name__ == "__main__":
    create_banking_application()

Expected Outcomes of Creating Applications

You can now see the applications under Applications sidebar section.

Read Applications

GraphQL

query {
  dataset(urn: "urn:li:dataset:(urn:li:dataPlatform:hive,fct_users_created,PROD)") {
    application {
      application {
        urn
        properties {
          name
          description
        }
      }
    }
  }
}

If you see the following response, the operation was successful:

{
  "data": {
    "dataset": {
      "application": {
        "application": {
          "urn": "urn:li:application:71b3bf7b-2e3f-4686-bfe1-93172c8c4e10",
          "properties": {
            "name": "Cancellation Processing"
          }
        }
      }
    }
  },
  "extensions": {}
}

Add Application

GraphQL

mutation batchSetApplication {
  batchSetApplication(
    input: {
      resourceUrns: [
        "urn:li:dataset:(urn:li:dataPlatform:bigquery,banking.public.customer,PROD)"
      ]
      applicationUrn: "urn:li:application:new-customer-signup"
    }
  )
}

If you see the following response, the operation was successful:

{
  "data": {
    "batchSetApplication": true
  },
  "extensions": {}
}

Python

# Inlined from /metadata-ingestion/examples/library/application_add.py
#!/usr/bin/env python3
from datahub.emitter.mce_builder import make_dataset_urn
from datahub.emitter.mcp import MetadataChangeProposalWrapper
from datahub.emitter.rest_emitter import DatahubRestEmitter
from datahub.metadata.schema_classes import ApplicationsClass


# Utility function for creating application URNs (not yet in SDK)
def make_application_urn(application_id: str) -> str:
    """Create a DataHub application URN."""
    return f"urn:li:application:{application_id}"


def add_application_aspect():
    emitter = DatahubRestEmitter(gms_server="http://localhost:8080", token="")
    dataset_urn = make_dataset_urn("snowflake", "database.schema.table", "PROD")

    application_urn = make_application_urn("my_application")
    applications_aspect = ApplicationsClass(applications=[application_urn])

    emitter.emit(
        MetadataChangeProposalWrapper(entityUrn=dataset_urn, aspect=applications_aspect)
    )

    print(f"Successfully added application: {application_urn}")


if __name__ == "__main__":
    add_application_aspect()

Expected Outcomes of Adding Application

You can now see the application has been added to the dataset.

Remove Applications

GraphQL

mutation batchSetApplication {
  batchSetApplication(
    input: {
      resourceUrns: [
        "urn:li:dataset:(urn:li:dataPlatform:bigquery,banking.public.customer,PROD)"
      ],
      applicationUrn: null
    }
  )
}

Expected Response:

{
  "data": {
    "batchSetApplication": true
  },
  "extensions": {}
}

Python

# Inlined from /metadata-ingestion/examples/library/application_remove.py
#!/usr/bin/env python3

from datahub.emitter.mce_builder import make_dataset_urn
from datahub.emitter.mcp import MetadataChangeProposalWrapper
from datahub.emitter.rest_emitter import DatahubRestEmitter
from datahub.metadata.schema_classes import ApplicationsClass


def remove_application_aspect():
    emitter = DatahubRestEmitter(gms_server="http://localhost:8080", token="")
    dataset_urn = make_dataset_urn("snowflake", "database.schema.table", "PROD")

    applications_aspect = ApplicationsClass(applications=[])

    emitter.emit(
        MetadataChangeProposalWrapper(entityUrn=dataset_urn, aspect=applications_aspect)
    )

    print("Successfully removed application")


if __name__ == "__main__":
    remove_application_aspect()