Configuring Databricks for Koalas

koala getting hlep from a Firefighter

The Apache Spark open source organization maintains all of the documentation for Apache Spark, which is a set of APIs which are used in Databricks and other big data processing applications.  The documentation provides the detailed information about the libraries, but the instructions for loading libraries in Databricks are not exactly the same as are used in Databricks, so if you follow the Spark installation instructions, you will get nowhere. If you follow the steps listed you will be up and running in no time.

Installing Options – Cluster or Notebook ?

If you are not using a ML workspace you can add in using dbutils like this.
dbutils.library.installPyPI("koalas")
dbutils.library.restartPython()

Unfortunately if you are using an ML workspace, this will not work and you will get the error message org.apache.spark.SparkException: Library utilities are not available on Databricks Runtime for Machine Learning. The Koalas github documentation  says “In the future, we will package Koalas out-of-the-box in both the regular Databricks Runtime and Databricks Runtime for Machine Learning”.  What this means is if you want to use it now

Most of the time I want to install on the whole cluster as I segment libraries by cluster.  This way if I want those libraries I just connect to the cluster that has them. Now the easiest way to install a library is to open up a running Databricks cluster (start it if it is not running) then go to the Libraries tab at the top of the screen. My cluster is called Yucca, and you can see that it is running because the circle next to the name is green.

After you are on the Libraries table you will see two buttons.  Click on the one labeled Install New.  A window will appear.  Select the library source of PYPI and in the Package text box enter the word koalas.  Then click on the install button.

Install Databricks LibraryThe installation may take a few minutes.  When it is complete you will see a green  status circle and the word installed.

After this you are ready to use the new library, once you import it as shown here.

 

Why do I want to install Koalas in Databricks?

If you have written Python code for Machine Learning, chances are you are using Pandas. Pandas dataframes are practically the standard for manipulating the data in Python.  They are not however part of the Spark API.  While you can move your Python code over to Databricks without making any changes to it, that is not advisable.  Databricks is able to scale pandas, so adding more resources to your code may not improve the performance.  When writing Python code for Databricks you need to use the Spark APIs in order to ensure that your code can scale and will perform optimally.   Prior to April of 2019, that meant that you had to use Spark dataframes and not pandas dataframes, which could involve a bit of rework when porting code as much code was written in pandas.  In April of last year Koalas was added to Spark, meaning that changing code to use a pandas dataframe to a koalas dataframe means that you only have to change one word. Koalas contains all of the functionalities of a pandas dataframe, so if you are familiar with one you can use the other.

More About Koalas

koala getting hlep from a Firefighter

Photo Credit:New York Fox 5

It is impossible for me to load the library without thinking about the Australian Bush Fires which are burning the homes of people and Koalas.  If your finances allow it, please consider donating to the firefighters as I am sure they can use help to save the homes of people and animals in Australia.

 

Regards,

Yours Always

Ginger Grant

Data aficionado et SQL Raconteur

 

Azure Machine Learning Workbench

Microsoft released Azure Machine Learning Workbench at the Ignite conference on September 25, 2017 as a public preview.  This tool is a new tool which they are adding to their Azure ecosystem, which includes the machine learning tool they introduced three years ago, Azure Machine Learning Studio. Microsoft has said they plan on keeping both products. When asked about the two products, they said that the earlier tool, Azure Machine Learning Studio, is targeted to developers who wanted to add machine learning to their current applications, as it is an easy to use tool that doesn’t require a person to be a trained data scientist.  Azure Machine Learning Workbench is targeted to data scientists who want to bring in other libraries, like TensorFlow for Python, and delve deep into the data.

Microsoft Moves into Machine Learning Management

Microsoft is looking for Azure Machine Learning Workbench for more than a tool to use for Machine Learning analysis. It is part of a system to manage and monitor the deployment of machine learning solutions with Azure Machine Learning Model Management. The management aspects are part of the application installation.  To install the Azure Machine Learning Workbench, the application download is available only by creating an account in Microsoft’s Azure environment, where a Machine Learning Model Management resource will be created as part of the install. Within this resource, you will be directed to create a virtual environment in Azure where you will be deploying and managing Machine Learning models.

This migration into management of machine learning components is part of a pattern first seen on the on-premises version of data science functionality.  First Microsoft helped companies manage the deployment of R code with SQL Server 2016 which includes the ability to move R code into SQL Server.  Providing this capability decreased the time it took to implement a data science solution by providing a means for the code can be deployed easily without the need for the R code to be re-written or included in another application. SQL Server 2017 expanded on this idea by allowing Python code to be deployed into SQL Server as well.  With the cloud service Model Management, Microsoft is hoping to centralize the implementation so that all Machine Learning services created can be managed in one place.

Hybrid Cloud, Desktop, and Python

While you must have an Azure account to use the Machine Learning Workbench, the application is designed to run on a locally on either a Mac or Windows computer.  There is a developer edition of the tool so that one can learn the tool and not incur a bill, which is the case with the previous product, Azure Machine Learning.  The download of Machine Learning Workbench must be accessed within an Azure account and is installed to your local computer.  When running the application from your computer, the application will prompt to log into your Azure account to load Azure Machine Learning Workbench.

The application is designed to use and create Python code.  Azure Machine Learning Workbench does not contain any accommodation to incorporate machine learning components written in R, just Python.  If you have created machine learning components using R, they can be incorporated into the Azure Machine Learning Model Management if you create webservices which encapsulate the R code. The R code does not interface into Workbench, but can be made to be a part of the managed projectes in Azure. While it is possible to create a webservice for R with the earlier product with Azure Machine Learning, there is no direct way to include R with Azure Machine Learning Workbench.  There are a number of sample templates to get started using Python templates including the ubiquitous Iris dataset, Linear regression and several others.   Once the project is created, you can use your favorite IDE, it creates python code which can be read anywhere.

Staying within Machine Learning Workbench application allows you access to arguably one of the neatest parts of the Machine Learning Workbench, the data parser. This tool which was originally code-named project Pendleton and designed to be an intuitive way to modify the contents of data even better than the previous leader in parsing data, Power BI’s Power Query.

You can select the option “Derive column by example” or “Split Column by Example” and then start typing in a new column.  For example, if you want to separate a column which contains the date and the time, if you right click on that date column and select “Split Column by Example” then type the date in the new column provided, the application will immediately determine that you want two columns and crate them. The date column and a time column be created for you after typing in one date.  After the sample columns have been created, you can approve the change or reject it if does not work how you want to.

Like Power Query, each change made to the data is included in the window called Steps on the right side of the application window. When you are done modifying the data, right click on the Data Preparations source icon, which in my example is called UFO Clean, to and the UI changes made to the data are used to create Python code to perform the changes. The generated Python code can be used to the source data programmatically.

The next step in the process is to write the python code needed to evaluate the data and create a model which would in my case determine where and when you are most likely to see the next UFO based on the dataset I have included in my project.  Unlike it’s counterpart Azure Machine Learning, you will need to know how to write the necessary code needed to create a machine learning analysis in Python for Azure Machine Learning Workbench. One could write the Python code to create a machine learning analysis in any Python editor.  If you chose to use Azure Machine Learning, the Python library scikit-learn is installed as part of the application.  Other libraries which you may want to use, such as the common library matplot, you will need to load within Azure Machine Learning Workbench.

Web Service: How Azure Machine Learning Workbench Solutions are Deployed

To deploy a package, you will need to export the completed model serialized Python object, with the Python Module, Pickle. This will create a file with the suffix of pkl, which is the file that you will be deploying. Azure Machine Learning Workbench expects that you will be deploying via Docker containers or creating an Azure cluster.  You will need to register the Docker container in the Machine Learning Container for it to be deployed.

Yours Always,

Ginger Grant

Data aficionado et SQL Raconteur