Apache Kafka Interview Questions

Apache Kafka Interview Questions

Apache Kafka is buzzing these days, and there are many companies using this technology. When used properly, and using the right cases, Kafka has distinct attributes making Kafka a highly attractive option to integrate data. So, companies these days are looking for aspirants who know Kafka well and can use the right cases. Though you know Kafka very well, sometimes you may not be able to do good in interviews because of missing out on the very basics or minute information. So, to help you out with it, here are a few Apache Kafka Interview Questions that will help you land a job.

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Apache Kafka Interview Questions

The offset is a unique id assigned to the partitions, which contains messages.The most important use of offset is that it identifies the messages through the id, which are available in the partitions.

No, it is merely not possible to use Kafka without the Zookeeper, as the user will not be able to connect directly to the Kafka server. And, if for some reason, the Zookeeper is down then the user will not be able to access any of the client requests.

Kafka messages can simply be defined as byte arrays that are used by developers to store objects in the format of String, JSON, and Avro.

 

In Kafka, the message broker is meant to be the message server that holds the capability of storing publisher messages.

The Kafka cluster holds all the published records, whether or not they have been consumed using a configurable retention period.

There are four major APIs available in Apache Kafka:

  • Producer API
  • Consumer API
  • Streams API
  • Connector API

By adjusting three or four properties as follows, you can successfully send large messages without encountering any exceptions.

  • Consumer side – fetch.message.max.bytes
  • Broker side – replica.fetch.max.bytes
  • Broker side – message.max.bytes
  • Broker side (Per topic) – max.message.bytes

Though both of them are used for real-time processing, Kafka is more scalable and ensures message durability.

It is nothing but an exclusive concept of Kafka. Each consumer groups has one or more consumers who consume subscribed topics.

To achieve the FIFO behavior with Kafka, follow the steps mentioned below:

Set enable.auto.commit=false

  • After processing the message, don’t make a call to consumer.commitSync();
  • Make a call to ‘subscribe’ and register consumer to a topic.
  • Implement a consumerRebalance Listener and perform consumer.seek(topicPartition,offset); within the listener.
  • Process the messages, hold each message’s offset, store the processed message’s offset with that of the processed message using atomic-transaction.
  • Implement idempotent as a safety net.

Zookeeper is used to store and preserve offset related information that is used to consume a particular topic by a specific consumer group, within the Kafka environment.

Though we cannot find a system with the same concept of Kafka, you can still consider other message brokers such as ActiveMQ, ZeroMQ, RabbitMQ etc.

Apart from having a traditional messaging technique, Apache Kafka has the following benefits:

  • It is fast
  • The data is partitioned and streamlined over a cluster for larger scalability.
  • It is durable
  • Distributed by design

Kafka was written in Java and Scala programming languages.

It is a publish-subscribe messaging application and an open source message broker project started by Apache software. Kafka was designed based on transactional logs design.