Kafka Project Fundamentals

Aug 11, 2025

Confluent Cloud is enterpise software.
Making personal Project then use Open source Apache kafka.

Zookeeper port - 2181. Then Kafka Server port 9092. Apache Kafka latest bin zip download and put in C drive then open cmd from the bin path. In different folder then the cmd throw the error like the input line is long error.

First start the zookeeper and then the kafka server.

C:\kafka_2.12-3.9.1>bin\windows\zookeeper-server-start.bat config\zookeeper.properties

C:\kafka_2.12-3.9.1>bin\windows\kafka-server-start.bat config\server.properties

Producer say on port 9191. Consumer say port on 9292.

Create a topic

 C:\kafka_2.12-3.9.1> bin\windows\kafka-topics.bat --create --topic demo_topic_1 --bootstrap-server localhost:9092 --partitions 3 --replication-factor 1

Topic name - demo_topic_1
Bootstrap-server port - localhost:9092

List of all the topic in a bootstrap server.

C:\kafka_2.12-3.9.1> bin\windows\kafka-topics.bat --list --bootstrap-server localhost:9092

Describe one topic

C:\kafka_2.12-3.9.1>bin\windows\kafka-topics.bat --bootstrap-server localhost:9092 --describe --topic demo_topic_1

The output.

Topic: demo_topic_1     TopicId: 0pv0RmQqSiClY81hFOWdGQ PartitionCount: 1       ReplicationFactor: 1    Configs:
Topic: demo_topic_1     Partition: 0    Leader: 0       Replicas: 0     Isr: 0  Elr: N/A        LastKnownElr: N/A

One health topic should have value 1. Partition: 0 Leader: 1 Replicas: 1 Isr: 1 It is 0 means kafka br

Kafka Consumer offset is one software where we need to add the port and then can see the topic details.

In Offset Explorer connect the cluster.

Delete one topic

C:\kafka_2.12-3.9.1>bin\windows\kafka-topics.bat --bootstrap-server localhost:9092 --delete --topic topic-Name

Produce message and Consume Message

C:\kafka_2.12-3.9.1>bin\windows\kafka-console-producer.bat --topic demo_topic_1 --bootstrap-server localhost:9092
> Hello
> World

## When there are multiple broker list.
C:\kafka_2.12-3.9.1>bin\windows\kafka-console-producer.bat --topic demo_topic_1 --bootstrap-server broker1:9092,broker2:9092,broker3:9092

Consumer command in a terminal.

C:\kafka_2.12-3.9.1>bin\windows\kafka-console-consumer.bat --topic demo_topic_1 --bootstrap-server localhost:9092 --from-beginning
C:\kafka_2.12-3.9.1>bin\windows\kafka-console-consumer.bat --bootstrap-server localhost:9092 --topic TOPIC_A --partition 0 --from-beginning

When produce multiple message say one file of data to produce in the topic.

Produce a large file in the message - C:\kafka_2.12-3.9.1>bin\windows\kafka-console-producer.bat --topic demo_topic_1 --bootstrap-server localhost:9092 <filePathInSystem>

filePathInSystem can be like Users/Download/File.csv

Bootstrap server Cluster Endpoints.

The bootstrap server of confluent looks like lkc-3r55qm-6k5r02.us-central1.gcp.glb.confluent.cloud:9092 In the confluent cloud set the env like dev, prd, stg then there will be cluste and in the cluster settings we can see the bootstrap server.

Dependency Needed

Kafka Streams, Kafka Avro Serializer, Apache Kafka. One thing the confluent io dependency not present in the springinitilizer platform. Then search for the dependency in Maven.

<!-- https://mvnrepository.com/artifact/io.confluent/kafka-avro-serializer -->
<dependency>
    <groupId>io.confluent</groupId>
    <artifactId>kafka-avro-serializer</artifactId>
    <version>7.8.0</version>
</dependency>

In gradle project we need to modify the dependency like groupId:artifactId:version like io.confluent:kafka-avro-serializer:7.8.0

In the build.gradle we need to add the dependency.

dependencies {
  implement io.confluent:kafka-avro-serializer:7.8.0
}

In the config/server.properties there will be the listeners code.

broker.id=1
listeners=PLAINTEXT://localhost:9092
advertised.listeners=PLAINTEXT://localhost:9092