Top Azure Databricks Interview Questions and Answers
Welcome to our comprehensive guide on Azure Databricks interview questions and answers! Whether you’re a seasoned data engineer or just starting your journey, this blog will help you prepare effectively for your upcoming interviews. We’ve curated a list of top questions along with simplified explanations to ensure you’re well-equipped to showcase your skills and land your dream job in Azure Databricks. Let’s dive in!
Azure Databricks is a cloud-based data engineering and analytics platform built on Apache Spark. It enables users to process and analyze large volumes of data efficiently, offering features like machine learning, interactive workspaces, and collaborative notebooks. With Azure Databricks, teams can work together seamlessly to derive insights from data, build machine learning models, and deploy data-driven solutions at scale. It provides a unified environment for data engineers, data scientists, and business analysts to collaborate on data projects, making it easier to develop, deploy, and manage data pipelines and analytics workflows. Azure Databricks integrates with other Azure services, providing a comprehensive solution for big data processing and analytics in the cloud.
What is databricks?
Databricks is a company that was established in 2013 and is based in San Francisco, California. They’ve created a cloud-based platform called “Databricks” that is built on Apache Spark technology. This platform is used for tasks like data engineering, machine learning, and collaborative data science.
With Databricks, teams of data engineers, data scientists, and business analysts can collaborate on projects. It offers a web-based notebook environment where users can easily develop, run, and share data analysis projects.
Moreover, Databricks provides tools for tasks like data ingestion, transformation, and preparation. It also offers advanced analytics capabilities such as graph processing, time-series analysis, and geospatial analysis. Overall, Databricks is a comprehensive platform for handling various aspects of data projects in a collaborative manner.
What is Key service capabilities of databricks?
Key Service Capabilities:
1. Optimized Spark Engine:Easily process data on a flexible infrastructure that adjusts automatically, using a supercharged version of Apache Sparkâ„¢, giving you up to 50 times faster performance.
2. Machine Learning Runtime: Access preconfigured machine learning environments with just one click. Use popular frameworks like PyTorch, TensorFlow, and scikit-learn to enhance your machine learning tasks.
3. MLflow: Keep track of experiments, share results, and manage models collaboratively from one central location.
4. Choice of Language: Work in your preferred programming language, whether it’s Python, Scala, R, Spark SQL, or .Net. This applies to both serverless and provisioned compute resources.
5. Collaborative Notebooks: Easily explore data, share insights, and build models together using the languages and tools you’re comfortable with.
6. Delta Lake: Improve data reliability and scalability in your existing data lake with an open-source storage layer designed for managing data throughout its lifecycle.
7. Native Integrations with Azure Services: Seamlessly integrate with Azure services like Azure Data Factory, Azure Data Lake Storage, Azure Machine Learning, and Power BI to create comprehensive analytics and machine learning solutions.
8. Interactive Workspaces: Foster collaboration among data scientists, data engineers, and business analysts with interactive workspaces.
9. Enterprise-Grade Security: Ensure data security with native security measures that protect your data and create secure analytics workspaces for thousands of users and datasets.
10. Production-Ready: Run and scale your most important data workloads confidently on a trusted platform. Benefit from ecosystem integrations for continuous integration/continuous deployment (CI/CD) and monitoring to ensure smooth operations.
Define Databricks
Databricks is a cloud-based tool on Azure that helps handle large amounts of data.
What is DBU?
DBU stands for Databricks Unified. It’s a way Databricks handles resources and calculates prices.
What is Microsoft Azure?
Microsoft Azure is a platform for cloud computing. It allows users to access services whenever they need them.
What distinguishes Azure Databricks from Databricks?
Azure Databricks is a partnership between Microsoft and Databricks to enhance analytics and modeling.
What are the benefits of using Azure Databricks?
Azure Databricks offers cost reduction, increased productivity, and improved security.
Can Databricks be used along with Azure Notebooks?
Yes, but data transmission requires manual coding unless you use Databricks Connect for seamless integration.
What are the various types of clusters present in Azure Databricks?
Azure Databricks has Interactive, Job, Low-priority, and High-priority clusters.
What is caching?
 Caching stores data temporarily, reducing the need to fetch it from the server repeatedly.
Would it be ok to clear the cache?
Yes, it’s fine to clear the cache as it’s not essential for any program.
What is autoscaling?
Autoscaling automatically adjusts the cluster size based on demand.
Would you need to store an action’s outcome in a different variable?
 It depends on how you plan to use the outcome.
Should you remove unused Data Frames?
It’s not necessary unless you’re using cache, which can consume network resources.
What are some issues you can face with Azure Databricks?
Cluster creation failures due to insufficient credits, Spark errors from incompatible code, and network issues.
What use is Databricks file system for?
 It ensures data durability even after removing Azure Databricks nodes.
How to troubleshoot issues related to Azure Databricks?
Start with documentation for common issues and contact Databricks support if needed.
Is Azure Key Vault a viable alternative to Secret Scopes?
Yes, it’s possible but requires setup.
How do you handle Databricks code while working in a team using TFS or Git?
Use Git for version control as TFS isn’t supported.
What languages are supported in Azure Databricks?
Python, Scala, R, and SQL.
Can Databricks be run on private cloud infrastructure?
Currently, it’s available on AWS and Azure, but it’s possible to set up your own cluster using open-source Spark.
Can you administer Databricks using PowerShell?
While not officially supported, there are PowerShell modules available.
What is the difference between an instance and a cluster in Databricks?
An instance runs the Databricks runtime, while a cluster is a group of instances used for Spark applications.
How to create a Databricks private access token?
Go to user profile, select user settings, and access the access tokens tab to generate a new token.
What is the procedure for revoking a private access token?
Go to user profile, select user settings, access the access tokens tab, and click the ‘x’ next to the token to revoke it.
What is the management plane in Azure Databricks?
It’s how you manage and monitor your Databricks deployment.
What is the control plane in Azure Databricks?
It manages Spark applications.
What is the data plane in Azure Databricks?
It handles data storage and processing.
What is the Databricks runtime used for?
It executes the Databricks platform’s modules.
What use do widgets serve in Databricks?
Widgets customize panels and notebooks by adding variables.
Why is it necessary for us to use the DBU Framework?
The DBU Framework simplifies the process of building applications on Databricks to handle large amounts of data. It includes tools like a command line interface (CLI) and software development kits (SDKs) in Python and Java.
Is it possible to manage Databricks using PowerShell?
No, you can’t manage Databricks with PowerShell because it’s not compatible. However, you can use other methods like the Azure command line interface (CLI), the Databricks REST API, or the Azure portal.
Which is better: a Databricks instance or a cluster?
The control plane manages various Spark applications and includes the Spark user interface and Spark history server.
Is there a way to stop a Databricks process in progress?
Yes, you can stop a running job in Databricks by going to the Jobs page, selecting the job, and choosing the Cancel-Job option from the context menu.
What is a delta table in Databricks?
A delta table stores data in Databricks Delta format, ensuring compliance with ACID transactions and enabling fast reads and writes.
What is the platform for executing Databricks applications?
The platform for executing Databricks applications is called Databricks Runtime. It provides all necessary components for building and running Spark applications.
What is Databricks Spark?
Databricks Spark is the result of forking Apache Spark to enhance its integration with Databricks.
Can Databricks be accessed locally or only through the cloud?
Databricks is designed for the cloud, but Apache Spark, the technology behind Databricks, can be used locally. However, using Databricks with local data may cause connectivity issues.
Is Databricks a Microsoft subsidiary?
No, Databricks is an open-source project based on Apache Spark. Microsoft announced Azure Databricks, a cloud platform including Databricks, as part of a partnership.
What types of cloud services does Databricks offer?
Databricks offers software as a service (SaaS), allowing users to leverage clusters to manage storage efficiently.
Which category of cloud service does Azure Databricks belong to?
Azure Databricks is a platform as a service (PaaS) built on top of Microsoft Azure and Databricks.
What are the differences between Microsoft Azure Databricks and Amazon Web Services Databricks?
Azure Databricks combines Azure and Databricks features seamlessly, providing advantages like Active Directory authentication and integration with various Azure services. AWS Databricks is simply Databricks hosted on AWS cloud.
What does "reserved capacity" mean in Azure?
Reserved capacity in Azure Storage guarantees customers a set amount of storage space during a specified period, offering cost savings.
What is a Databricks personal access token? How do you create one?
A Databricks personal access token is a way to verify an identity in Azure Databricks. It can be used instead of a username and password. Creating one is simple:
- Click your username in the top bar of your Azure Databricks workspace.
- Select “User Settings” from the drop-down menu.
- Go to the “Access tokens” tab.
- Click “Generate new token.”
- Click “Generate,” then copy the token.
- Click “Done” to finish.
What are the components of Azure Databricks?
Azure Databricks has several key components:
- Workspace: This is where developers work collaboratively using notebooks. It includes version control, security features, and tools for machine learning and visualization.
- Apache Spark: This open-source processing engine handles data processing tasks on the Databricks platform, especially useful for large datasets and machine learning.
- Managed Infrastructure: Managed clusters of virtual machines speed up data processing by distributing work. Users can customize these clusters and scale them as needed.
- Delta: Delta is a file format designed for handling large datasets efficiently, with features like transaction logs and metadata.
- MLflow: An open-source framework for managing the machine learning lifecycle, helping to deploy ML models into production.
- SQL Analytics: A part of Azure Databricks focused on SQL analytics, allowing users to connect BI tools and run SQL queries on Spark clusters.
Define workspaces in Azure Databricks.
Workspaces in Azure Databricks are instances of Apache Spark where objects like experiments, notebooks, and dashboards are organized into folders. They provide access to data, jobs, and clusters, serving as environments for accessing Databricks assets.
Can Azure Key Vault be an alternative to Secret Scopes?
Yes, Azure Key Vault can be an alternative to Secret Scopes. It’s a secure storage service for keys, secrets, and certificates. You can set it up to store confidential information and restrict access. It simplifies managing secrets across multiple workspaces.
Can we reuse code in the Azure notebook? How to do it?
Yes, code can be reused in Azure notebooks by importing it. There are two ways to import code:
- If the code is on a different workstation, create a component (module/jar file) for it first, then import it.
- If the code is on the same workstation, import it directly and use it in your notebook.
What operations can be performed via Azure command-line interface?
With Azure CLI, you can perform various tasks in Azure Databricks:
- Provision resources like clusters.
- Create and run data processing tasks.
- Manage notebooks and folders.
- Troubleshoot technical issues efficiently.
What is Azure Databricks, and how is it different from traditional data bricks?
Azure Databricks is an open-source platform for processing big data, using Apache Spark on the Azure cloud. It’s used mainly for preparing and analyzing data. Data is imported into Azure using tools like Data Factory, then stored in permanent storage like ADLS Gen2 or Blob Storage. In Databricks, machine learning is applied to analyze the data, and insights are loaded into Azure analysis services like Azure Synapse Analytics or Cosmos DB. Finally, these insights are visualized using analytical reporting tools like Power BI for end-users.
What is Serverless Database Processing in Azure?
Serverless database processing in Azure means running code without worrying about managing servers. The code is executed independently of physical servers, following stateless code principles. Users pay only for the computing resources they use during code execution, making it cost-effective. This approach offers flexibility and scalability without the need for server management.
What operations can be performed via Azure command-line interface?
With Azure CLI, you can perform various tasks in Azure Databricks:
- Provision resources like clusters.
- Create and run data processing tasks.
- Manage notebooks and folders.
- Troubleshoot technical issues efficiently.
Primary benefits offered by Azure Databricks
Primary Benefits of Azure Databricks:
Azure Databricks is a cloud-based data management solution known for its ability to handle large amounts of data and perform machine learning tasks efficiently. Some key benefits include:
Compatibility with Various Programming Languages: Azure Databricks works with languages like Python, R, and SQL, making it easy for users to work with distributed analytics without needing to learn new coding skills.
Unified Workspace for Collaboration: It offers a unified workspace where teams can collaborate in a multi-user environment to develop Spark-based machine learning and streaming applications.
Monitoring and Recovery Features: Azure Databricks includes monitoring and recovery features that automate the failover and recovery of clusters, enhancing security and performance in cloud environments.
Explain the types of clusters that are accessible through Azure Databricks as well as the functions that they serve.
Types of Clusters in Azure Databricks:
Azure Databricks provides four types of clusters for different purposes:
Interactive Clusters: These clusters are used for ad hoc analysis and discovery, allowing users to interact with data with high concurrency and low latency.
Job Clusters: They are used for executing batch jobs, with the ability to automatically scale up or down based on demand.
Low-Priority Clusters: Cost-effective option suitable for low-demand applications such as development and testing, but with lower performance compared to other clusters.
High-Priority Clusters: Offer the best performance but come at a higher cost, suitable for processing production-level workloads.
How do you handle the Databricks code when working with a collaborative version control system such as Git or the team foundation server (TFS)?
Handling Databricks Code with Version Control Systems:
When working with collaborative version control systems like Git or TFS, Azure Databricks notebooks can easily be connected to these systems for code management. Users can integrate notebooks with Git, Bitbucket Cloud, or TFS, allowing for seamless collaboration and version control.
For managing Databricks code, users typically create notebooks, upload them to the repository, and update them as needed. Git offers granular rights management, while TFS provides enhanced security features, allowing users to control access to code repositories effectively.
Can Databricks work with a private cloud?
Yes, Databricks can be used with a private cloud environment, but there are limitations. Databricks mainly operates on platforms like Amazon Web Services (AWS) and Microsoft Azure, utilizing open-source Spark technology. While it’s possible to set up your own cluster in a private cloud, you won’t have access to the advanced administration tools provided by Databricks.
What are the Benefits of Using Kafka with Azure Databricks?
Using Kafka with Azure Databricks allows for real-time streaming data processing and analysis. Kafka is a decentralized streaming platform that enables gathering data from various sources like sensors and logs, facilitating real-time processing and analysis of streaming data.
Can I use multiple languages in a single notebook?
Yes, you can use multiple languages like Scala and Python in a single notebook. For example, you can create a Scala DataFrame and use it as a reference in Python. However, it’s essential to consider readability and maintainability when mixing languages in a notebook to ensure ease of debugging and collaboration.
Can I write code with VS Code and use its features with Databricks?
Yes, you can write code in VS Code and take advantage of features like syntax highlighting and IntelliSense. While you won’t have the full notebook experience, you can still write Python or Scala scripts. Alternatively, you can use Databricks Connect to work with VS Code and run critical tasks like unit tests.
Can Databricks be installed on a private cloud?
No, Databricks requires a public cloud provider like AWS or Microsoft Azure to run. While it’s technically possible to set up your own cluster in a private cloud, you won’t have access to the advanced features and control provided by Databricks on public cloud platforms.