Introduction to Kafka Interview Questions and Answers
Kafka is an open-source publisher-subscriber model, which is written in Scala. It is one of the most popular tools which is being used in data processing these days. People prefer Kafka because it provides extensive throughputs and low latency, making it easier to handle real-time data efficiently. It also enables easy data partitioning, scalability, and low latency. These features have ignited a wide range of jobs for people skilled in Kafka. Below is a few regularly asked question which can help you crack that important interview that you have.
If you are looking for a job related to Kafka, you need to prepare for the 2021 Kafka Interview Questions. Every interview is indeed different as per the different job profiles. Here, we have prepared the important Kafka Interview Questions and Answers, which will help you succeed in your interview.
In this 2021 Kafka Interview Questions article, we shall present the 10 most important and frequently asked Kafka Interview questions. These questions are divided into two parts are as follows:
Part 1 – Kafka Interview Questions (Basic)
This first part covers basic Kafka Interview Questions and Answers.
Q1. What is Kafka, and what are the various components of Kafka?
Kafka is said to be a pub-sub messaging model which was developed using Scala. It is an open-source application that was started by Apache software. Kafka is mainly designed upon transactional logs design. It has unique features which make it the best choice for data integration these days and is among the famous data processing tools. The important features are data partitioning, scalability, low-latency, high throughputs, stream processing, durability, zero data loss, etc. The main components of Kafka are:
- Topic: A bunch of messages which are of the same type come under the same topic.
- Producer: A producer, as the name suggests, produces messages and can communicate to the selected topic.
- Brokers: These act as a channel between the producers and consumers. They are a set of servers where the published messages are stored.
- Consumer: The consumer is the one who is going to the consumer the published data. It can subscribe to different topics and then pull data from the brokers.
Q2. What are a leader and follower in Kafka?
Kafka creates partitions based on offset and consumer groups. Every partition in Kafka has a server that plays the role of leader. One of them being the leader, there can be none or more servers which will act as a follower. The leader has assigned itself tasks that read and write requests for partition. On the other hand, followers need to follow the leader and replicate what is being told by a leader. If the leader fails, like in the real-life, one of the followers needs to take over as the leader’s role. This can happen at the time of server faults. This ensures that the load is balanced properly on the server and also ensures the system’s stability.
Let us move to the next Kafka Interview Questions.
Q3. What is a Replica? Why are the replications considered to be critical in the Kafka environment?
A list of essential nodes responsible for logging for any particular partition is known as a replica. A replica node does not matter whether it plays the role of leader or follower. The vital reason for the need for replication is that they can be consumed again in any uncertain event of machine error or program malfunction or system is down due to usual frequent updates to make sure that no data is lost or corrupted replication makes sure that all messages are published properly and are not lost.
Q4. What is Zookeeper in Kafka? Can Kafka be used without Zookeeper?
This is the basic Kafka Interview Question asked in an interview. Zookeeper is used for distributed applications that Kafka adapts. It helps Kafka in managing all sources properly. Zookeeper is an open-source, high-performance, and provides a complete coordination service.
No, it is impossible to skip the Zookeeper and go directly to the Kafka broker. Zookeeper manages all Kafka resources, and hence if Zookeeper is down, it cannot serve any client service requests. The main job of a zookeeper is to be a channel of communication for the different nodes existing in a cluster. Zookeeper in Kafka is used to commit to the offset. If a node fails, it can be easily retrieved from the offset which was previously committed. The zookeeper also takes care of activities like leader detection, distributed synchronization, configuration management, etc. With all of these, it also does the job of identifying the new node that leaves or joins the cluster nodes, all nodes’ status, etc.
Q5. How are the messages consumed by a consumer in Kafka?
By making use of send file API, the transfer of messages is done in Kafka. Using this file, the transfer of bytes occurs from the socket to disk through the kernel space-saving copies and the calls between kernel user and back to the kernel.
Part 2 – Kafka Interview Questions (Advanced)
Let us now have a look at the advanced Kafka Interview Questions.
Q6. What is SerDes?
SerDes stands for serializer and deserializer. For any Kafka stream to materialize the data whenever necessary, it is vital to provide SerDes for all data types or record and record values.
Q7. What is the way to send large messages with Kafka?
To send larges messages using Kafka, you must adjust a few properties. By making these changes, you will not face any exceptions and will be able to send all messages successfully. Below are the properties which require a few changes:
At the Consumer end – fetch.message.max.bytes
At the Broker, end to create replica– replica.fetch.max.bytes
At the Broker, the end to create a message – message.max.bytes
At the Broker end for every topic – max.message.bytes
Let us move to the next Kafka Interview Questions.
Q8. What is Offset?
An offset can be called a unique identifier that is assigned to all different partitions. These partitions contain messages. The most important use of offset is that it can help identify the messages through the offset id. These offset ids are available in all the partitions.
Q9. What is Multi-Tenancy?
This is the most asked Kafka Interview Questions in an interview. Kafka can be deployed easily as a multi-tenant solution. The configuration for different topics on which data is to be produced or consumed this feature is enabled. With all this, it also provides operational support for different quotas.
Q10. For its optimal performance, how will you tune Kafka?
Different components are present in Kafka. To tune Kafka, it is important to tune its components first. This includes tuning Kafka producers, Tuning Kafka consumers, and also tuning the Kafka brokers.
This has been a guide to the list Of Kafka Interview Questions and Answers. Here we have listed the top 10 Interview Questions and Answer questions in an interview with detailed responses. You may also look at the following articles to learn more –