Custom SerDes in Kafka - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does SerDes stand for in Kafka?

SerDes stands for Serializer/Deserializer. It converts data to bytes for sending and back to objects when receiving.

beginner

Why create a custom SerDes in Kafka?

To handle special data formats or complex objects that default serializers can't process well.

intermediate

What two main methods must a Kafka Serializer implement?

The methods are serialize(String topic, T data) to convert data to bytes, and close() to release resources.

beginner

What is the role of the Deserializer in a Kafka SerDes?

It converts byte arrays back into objects so the consumer can use the data in its original form.

intermediate

How do you register a custom SerDes in Kafka producer or consumer?

You set the key.serializer or value.serializer (for producer) and key.deserializer or value.deserializer (for consumer) properties to your custom Serializer and Deserializer classes respectively.

What is the main purpose of a Kafka Serializer?

A Send messages to Kafka topics

B Convert byte arrays to objects

C Convert objects to byte arrays

D Manage Kafka partitions

A serializer converts objects into byte arrays so Kafka can send them over the network.

Which interface must you implement to create a custom Kafka Deserializer?

A org.apache.kafka.common.serialization.Deserializer

B org.apache.kafka.common.serialization.Serializer

C org.apache.kafka.clients.consumer.Consumer

D org.apache.kafka.clients.producer.Producer

The Deserializer interface is used to convert byte arrays back into objects.

If your data is a complex Java object, what is a good reason to create a custom SerDes?

A Default SerDes may not handle complex objects correctly

B To speed up Kafka brokers

C To avoid using Kafka topics

D To change Kafka partitioning

Custom SerDes allow you to control how complex objects are converted to bytes and back.

Where do you specify your custom SerDes class in Kafka configuration?

A In the consumer group ID

B In the Kafka broker settings

C In the Kafka topic name

D In the serializer and deserializer properties

You set the serializer and deserializer properties to your custom class in producer or consumer configs.

What happens if you don't implement the close() method in your custom SerDes?

A Kafka will not start

B Resources may not be released properly

C Messages will be lost

D Serialization will fail

The close method helps clean up resources like streams or buffers to avoid memory leaks.

Explain how a custom SerDes works in Kafka and why you might need one.

Think about how data travels from your program to Kafka and back.

Describe the steps to create and use a custom SerDes in a Kafka application.

Focus on coding and configuration steps.