Transform data by running a Python activity in Azure Databricks

Artikkeli
10/03/2024

APPLIES TO: Azure Data Factory Azure Synapse Analytics

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The Azure Databricks Python Activity in a pipeline runs a Python file in your Azure Databricks cluster. This article builds on the data transformation activities article, which presents a general overview of data transformation and the supported transformation activities. Azure Databricks is a managed platform for running Apache Spark.

For an eleven-minute introduction and demonstration of this feature, watch the following video:

Add a Python activity for Azure Databricks to a pipeline with UI

To use a Python activity for Azure Databricks in a pipeline, complete the following steps:

Search for Python in the pipeline Activities pane, and drag a Python activity to the pipeline canvas.
Select the new Python activity on the canvas if it is not already selected.
Select the Azure Databricks tab to select or create a new Azure Databricks linked service that will execute the Python activity.
Select the Settings tab and specify the path within Azure Databricks to a Python file to be executed, optional parameters to be passed, and any additional libraries to be installed on the cluster to execute the job.

Databricks Python activity definition

Here is the sample JSON definition of a Databricks Python Activity:

{
    "activity": {
        "name": "MyActivity",
        "description": "MyActivity description",
        "type": "DatabricksSparkPython",
        "linkedServiceName": {
            "referenceName": "MyDatabricksLinkedService",
            "type": "LinkedServiceReference"
        },
        "typeProperties": {
            "pythonFile": "dbfs:/docs/pi.py",
            "parameters": [
                "10"
            ],
            "libraries": [
                {
                    "pypi": {
                        "package": "tensorflow"
                    }
                }
            ]
        }
    }
}

Databricks Python activity properties

The following table describes the JSON properties used in the JSON definition:

Property	Description	Required
name	Name of the activity in the pipeline.	Yes
description	Text describing what the activity does.	No
type	For Databricks Python Activity, the activity type is DatabricksSparkPython.	Yes
linkedServiceName	Name of the Databricks Linked Service on which the Python activity runs. To learn about this linked service, see Compute linked services article.	Yes
pythonFile	The URI of the Python file to be executed. Only DBFS paths are supported.	Yes
parameters	Command line parameters that will be passed to the Python file. This is an array of strings.	No
libraries	A list of libraries to be installed on the cluster that will execute the job. It can be an array of <string, object>	No

Supported libraries for databricks activities

In the above Databricks activity definition you specify these library types: jar, egg, maven, pypi, cran.

{
    "libraries": [
        {
            "jar": "dbfs:/mnt/libraries/library.jar"
        },
        {
            "egg": "dbfs:/mnt/libraries/library.egg"
        },
        {
            "maven": {
                "coordinates": "org.jsoup:jsoup:1.7.2",
                "exclusions": [ "slf4j:slf4j" ]
            }
        },
        {
            "pypi": {
                "package": "simplejson",
                "repo": "http://my-pypi-mirror.com"
            }
        },
        {
            "cran": {
                "package": "ada",
                "repo": "https://cran.us.r-project.org"
            }
        }
    ]
}

For more details refer Databricks documentation for library types.

How to upload a library in Databricks

You can use the Workspace UI:

Use the Databricks workspace UI
To obtain the dbfs path of the library added using UI, you can use Databricks CLI.

Typically the Jar libraries are stored under dbfs:/FileStore/jars while using the UI. You can list all through the CLI: databricks fs ls dbfs:/FileStore/job-jars

Or you can use the Databricks CLI:

Follow Copy the library using Databricks CLI
Use Databricks CLI (installation steps)

As an example, to copy a JAR to dbfs: dbfs cp SparkPi-assembly-0.1.jar dbfs:/docs/sparkpi.jar

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