20 NiFi Interview Questions and Answers

Apache NiFi is a powerful data processing tool that is gaining popularity in the big data community. If you’re interviewing for a big data position, it’s likely that you’ll be asked questions about NiFi. Knowing how to answer these questions can help you stand out from the other candidates and land the job. In this article, we’ll discuss some of the most common NiFi interview questions and how to answer them.

NiFi Interview Questions and Answers

Here are 20 commonly asked NiFi interview questions and answers to prepare you for your interview:

1. What is NiFi?

NiFi is a powerful tool for data processing and distribution. It is designed to be easy to use and easy to extend. NiFi can be used to process and distribute data in a variety of ways, including streaming data, batch data, and data from sensors.

2. How does NiFi compare with other data ingestion and ETL tools like Flume, Kafka, or Talend?

NiFi is a data ingestion and ETL tool that is designed to be highly configurable and easy to use. It can be used to ingest data from a variety of sources, and then perform a variety of transformations on that data before finally sending it to a destination. NiFi is unique in its ability to provide a graphical user interface that makes it easy to visually create and configure data flows. Additionally, NiFi is designed to be highly scalable and fault tolerant, making it an ideal tool for data ingestion and ETL in a big data environment.

3. Where can I download the latest version of NiFi?

The latest version of NiFi can be downloaded from the Apache NiFi website: https://nifi.apache.org/download.html

4. Can you explain what a flow file is in context of Apache NiFi?

A flow file is an object that represents data flowing through Apache NiFi. Flow files contain data and attributes that can be used to control the flow of that data through the NiFi system.

5. Can you give me some examples of real-world use cases for Nifi?

There are many use cases for Nifi, but some of the most popular include data ingestion and ETL, data warehousing, data lakes, and streaming data architectures.

6. What are the main components that make up an Apache Nifi instance?

The main components of an Apache Nifi instance are the FlowFile Repository, the Provenance Repository, the Content Repository, the Flow Controller, and the NiFi Web UI. The FlowFile Repository is where NiFi stores information about the FlowFiles that are currently being processed. The Provenance Repository is used to store information about the provenance of FlowFiles, and the Content Repository is used to store the actual content of FlowFiles. The Flow Controller is responsible for managing the flow of data through NiFi, and the NiFi Web UI is used to provide a graphical interface for interacting with NiFi.

7. What’s the difference between FlowFileAttributes and FlowFileContent?

FlowFileAttributes are metadata associated with a FlowFile, while FlowFileContent is the actual data contained in the FlowFile.

8. What’s the best way to achieve scalability when using Apache Nifi?

There are a few ways to achieve scalability when using Apache Nifi. One way is to use the NiFi Cluster Manager to manage and monitor a group of NiFi servers. Another way is to use NiFi’s built-in load balancing features to distribute load across multiple NiFi servers.

9. What are processors in NiFi? How do they work?

Processors are the basic building blocks of NiFi flows. They are responsible for taking in data, performing some kind of processing on that data, and then outputting the results. There are a wide variety of processors available, each with its own specific purpose. Some common examples include processors for extracting text from PDFs, converting JSON to XML, or encrypting data.

10. Can you explain how to create a custom processor in NiFi?

You can create a custom processor in NiFi by extending the AbstractProcessor class and overriding the onTrigger method. In the onTrigger method, you will need to implement the logic for your processor. You can access the NiFi FlowFile object to read and write data, and you can also use the NiFi ProcessContext object to access properties and variables.

11. What is provenance in the context of NiFi? Why is it important?

Provenance is the history of a given piece of data, and it is important in NiFi because it allows you to track where data came from and how it has been processed. This is useful for debugging purposes, as well as for understanding the data flow through a NiFi system.

12. What information is captured by NiFi Provenance Repository?

The NiFi Provenance Repository captures information about the dataflow through NiFi, including the data that is processed, the NiFi processors that are used, the NiFi connections that are used, and the NiFi parameters that are used.

13. What is the importance of Process Groups in NiFi?

Process Groups help to provide an additional level of organization and control within NiFi. By creating a Process Group, you can more easily monitor and manage the flow of data within NiFi. Additionally, Process Groups can be used to help control access to certain areas of the NiFi flow.

14. What is a Connection Queue in NiFi?

A Connection Queue is a queue of FlowFiles that are waiting to be processed by a downstream connection.

15. Can you tell me about the process used by NiFi to handle back pressure?

Back pressure is the name given to the process of slowing down or stopping the flow of data through a system when that system is becoming overwhelmed. This is done in order to prevent the system from becoming overloaded and crashing. NiFi uses a back pressure mechanism to automatically control the flow of data through the system in order to prevent data loss.

16. Is it possible to run NiFi as a cluster? If yes, then how?

Yes, it is possible to run NiFi as a cluster. In order to do so, you will need to start up multiple NiFi instances and then configure them to work together as a cluster. The specifics of how to do this will vary depending on your particular environment and setup.

17. What happens if a user tries to access a port that is already being used by another service?

If a user tries to access a port that is already being used by another service, then the user will be unable to access the port.

18. Can you explain how to configure SSL on NiFi?

You will need to generate a keystore and truststore for NiFi, and then configure the NiFi properties file to point to those files. You will also need to configure the appropriate ports for SSL communication.

19. What are the permissions required to run NiFi as a non-root user?

The permissions required to run NiFi as a non-root user are as follows: the user must have read/write permissions for the NiFi installation directory, read/write permissions for the NiFi working directory, and read permissions for all NiFi configuration files.

20. What are the different ways to get help from the community when using Apache NiFi?

There are a few different ways to get help from the community when using Apache NiFi. One way is to use the Apache NiFi mailing lists. You can also use the Apache NiFi forums. Finally, you can also try asking your question on Stack Overflow.