Updated May 10, 2023
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 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. These frequently asked questions can assist you in preparing for your important interview.
If you are looking for a job related to Kafka, you must prepare for the 2023 Kafka Interview Questions. Every interview is indeed different as per the various job profiles. Here, we have prepared the critical Kafka Interview Questions and Answers to help you succeed in your interview.
This 2023 Kafka Interview Questions article will present the ten most important and frequently asked Kafka Interview questions. These questions are divided into two parts 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?
Answer:
Kafka is said to be a pub-sub messaging model developed using Scala. It is an open-source application that was started by Apache software. The design of Kafka is primarily based on transactional logs. It has unique features that make it the best choice for data integration these days, and it is among the famous data processing tools. The essential 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 of the same type comes under the same topic.
- Producer: As the name suggests, a producer produces messages and can communicate with the selected topic.
- Brokers: These act as a channel between producers and consumers. These servers store the published messages.
- Consumer: The consumer is the one who is going to consume the published data. It can subscribe to different topics and then pull data from the brokers.
Q2. What are a leader and followers in Kafka?
Answer:
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 is the leader; there can be none or more servers which will act as a follower. The leader has assigned 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 real life, one of the followers needs to take over the leader’s role. This can happen at the time of server faults. Balancing the load on the server 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?
Answer:
A replica is a list of essential nodes responsible for logging for any particular partition. 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 frequent regular updates to make sure that no data is lost or corrupted; replication ensures that the system correctly publishes all messages and does not lose them.
Q4. What is Zookeeper in Kafka? Can Kafka be used without a zookeeper?
Answer:
This is the basic Kafka Interview Question asked in an interview. Kafka adopts ZooKeeper for distributed applications. It helps Kafka in managing all sources properly. Zookeeper is an open-source, high-performance, and provides a complete coordination service.
No, skipping the zookeeper and going directly to the Kafka broker is impossible. Zookeeper manages all Kafka resources; hence, if the zookeeper is down, it cannot serve 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. A node can be easily retrieved from the previously committed balance if it fails. The zookeeper also handles activities like leader detection, distributed synchronization, configuration management, etc. With all of these, it also identifies the new node that leaves or joins the cluster nodes, all nodes’ status, etc.
Q5. How does a consumer consume the messages in Kafka?
Answer:
Kafka uses the send file API to transfer messages. Using this file, the transfer of bytes occurs from the socket to disk through the kernel space-saving copies and the calls between the 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?
Answer:
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?
Answer:
To send large messages using Kafka, you must adjust a few properties. By making these changes, you will not face any exceptions and can 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?
Answer:
An offset can be called a unique identifier 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?
Answer:
These are the most asked Kafka Interview Questions in an interview. Deploying Kafka as a multi-tenant solution is a quick process. This feature enables the configuration of different topics for producing or consuming data. With all this, it also provides operational support for different quotas.
Q10. For its optimal performance, how will you tune Kafka?
Answer:
Different components are present in Kafka. To tune Kafka, it is essential to tune its components first. This includes tuning Kafka producers, Tuning Kafka consumers, and tuning the Kafka brokers.
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