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. The main reason that people are preferring Kafka is that it provides extensive throughputs and also provides low latency which makes it easier for it 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.
Now, if you are looking for a job which is related to Kafka then you need to prepare for the 2019 Kafka Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important Kafka Interview Questions and Answers which will help you get success in your interview.
In this 2019 Kafka Interview Questions article, we shall present 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 which 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 issue a communication 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: 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 is leader and follower in Kafka?
Kafka creates partitions based on offset and consumer groups. Every partition in Kafka has a server which 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 to itself tasks which read and write requests for partition. Followers, on the other hand, need to follow the leader and replicate what is being told by a leader. If at all the leader fails, like the real life one of the followers need to take over as the role of leader. 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 Kafka environment?
A list of essential nodes which are responsible to log 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 of 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. In order 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 which are adapted by Kafka. 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 zookeeper is to be a channel of communication for the different nodes which are existing in a cluster. Zookeeper in Kafka is used to commit to the offset. If at all a node fails it can be easily retrieved from the offset which was previously committed. In addition to this 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 which leaves or joins the cluster nodes, the status of all nodes, etc.
Q5. How are the messages consumed by a consumer in Kafka?
By making use of send file API transfer of messages is done in Kafka. Using this file the transfer of bytes takes place 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?
In order 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 as a unique identifier which 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?
There are different components which are present in Kafka. In order 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 list Of Kafka Interview Questions and Answers so that the candidate can crackdown these Kafka Interview Questions easily. Here in this post, we have studied top Kafka Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –