Topic creation in Kafka - Mini Project: Build & Apply

Kafka Topic Creation

📖 Scenario: You are setting up a Kafka environment to handle messages for a small online store. You need to create a topic where order messages will be sent and received.

🎯 Goal: Create a Kafka topic named orders with 3 partitions and a replication factor of 1 using the Kafka command line tool.

📋 What You'll Learn

Create a topic named orders

Set the number of partitions to 3

Set the replication factor to 1

Use the Kafka kafka-topics.sh command line tool

💡 Why This Matters

🌍 Real World

Kafka topics organize messages by category, helping systems handle data streams efficiently.

💼 Career

Kafka topic creation is a fundamental skill for data engineers and backend developers working with real-time data pipelines.

1

Set up the Kafka topic creation command

Write the command to create a Kafka topic named orders using kafka-topics.sh with the --create option.

Kafka

# Write the kafka-topics.sh command to create the topic 'orders'
# Your code here

Hint

Use kafka-topics.sh --create --topic orders as the base command.

2

Add partitions configuration

Extend the command to set the number of partitions to 3 using the --partitions option.

Kafka

kafka-topics.sh --create --topic orders
# Add --partitions 3 to the command
# Your code here

Hint

Add --partitions 3 to specify the number of partitions.

3

Add replication factor configuration

Add the --replication-factor 1 option to the command to set the replication factor to 1.

Kafka

kafka-topics.sh --create --topic orders --partitions 3
# Add --replication-factor 1 to the command
# Your code here

Hint

Use --replication-factor 1 to set replication factor.

4

Display the created topic details

Write the command to describe the orders topic using kafka-topics.sh with the --describe option.

Kafka

kafka-topics.sh --create --topic orders --partitions 3 --replication-factor 1
# Write the command to describe the topic 'orders'
# Your code here

Hint

Use kafka-topics.sh --describe --topic orders to see topic details.

Practice

1. What is the main purpose of a topic in Kafka?

easy

A. To compile Java programs

B. To store user login credentials

C. To manage database connections

D. To organize messages like folders organize files

Solution

1. Step 1: Understand Kafka topic role

   A Kafka topic is a category or feed name to which messages are published.

2. Step 2: Compare options with topic function

   Only To organize messages like folders organize files correctly describes topics as organizing messages like folders organize files.

3. Final Answer:

   To organize messages like folders organize files -> Option D

4. Quick Check:

   Topic = Organize messages [OK]

Hint: Topics group messages like folders group files [OK]

Common Mistakes:

• Confusing topics with databases
• Thinking topics store user data
• Mixing topics with program compilation

2. Which command correctly creates a Kafka topic named orders with 3 partitions and replication factor 2?

easy

A. kafka-topics.sh --create --topic orders --partitions 3 --replication-factor 2 --bootstrap-server localhost:9092

B. kafka-create-topic orders 3 2

C. create-topic --name orders --partitions 3 --replicas 2

D. kafka-topics.sh --new --topic orders --partitions=3 --replicas=2

Solution

1. Step 1: Identify correct Kafka topic creation syntax

   The official command uses kafka-topics.sh with --create, --topic, --partitions, --replication-factor, and --bootstrap-server options.

2. Step 2: Match options with correct syntax

   kafka-topics.sh --create --topic orders --partitions 3 --replication-factor 2 --bootstrap-server localhost:9092 matches the correct syntax exactly; others use wrong commands or options.

3. Final Answer:

   kafka-topics.sh --create --topic orders --partitions 3 --replication-factor 2 --bootstrap-server localhost:9092 -> Option A

4. Quick Check:

   Correct syntax = kafka-topics.sh --create --topic orders --partitions 3 --replication-factor 2 --bootstrap-server localhost:9092 [OK]

Hint: Use kafka-topics.sh with --create and proper flags [OK]

Common Mistakes:

• Using wrong command names
• Missing --bootstrap-server option
• Incorrect option names like --replicas

3. What will happen if you run this command?

kafka-topics.sh --create --topic sales --partitions 5 --replication-factor 1 --bootstrap-server localhost:9092

medium

A. Creates a topic named 'sales' with 1 partition and replication factor 5

B. Fails because replication factor cannot be 1

C. Creates a topic named 'sales' with 5 partitions and replication factor 1

D. Fails due to missing zookeeper connection

Solution

1. Step 1: Analyze command parameters

   The command specifies topic 'sales', 5 partitions, replication factor 1, and bootstrap server.

2. Step 2: Understand Kafka topic creation rules

   Replication factor 1 is valid (means no replicas), and partitions set to 5 means 5 partitions created.

3. Final Answer:

   Creates a topic named 'sales' with 5 partitions and replication factor 1 -> Option C

4. Quick Check:

   Partitions=5, Replication=1 [OK]

Hint: Replication factor 1 means no replicas, partitions as given [OK]

Common Mistakes:

• Confusing partitions with replication factor
• Assuming replication factor 1 is invalid
• Expecting zookeeper connection with bootstrap-server

4. You tried to create a topic with this command:

kafka-topics.sh --create --topic logs --partitions two --replication-factor 3 --bootstrap-server localhost:9092

What is the error?

medium

A. Missing --create flag

B. Invalid number for partitions: 'two' should be a number

C. Replication factor cannot be 3

D. Bootstrap server address is incorrect

Solution

1. Step 1: Check partitions parameter

   The partitions option expects a number, but 'two' is a word, causing a syntax error.

2. Step 2: Verify other parameters

   Replication factor 3 and bootstrap server are valid; --create flag is present.

3. Final Answer:

   Invalid number for partitions: 'two' should be a number -> Option B

4. Quick Check:

   Partitions must be numeric [OK]

Hint: Partitions must be numeric, not words [OK]

Common Mistakes:

• Using words instead of numbers for partitions
• Assuming replication factor 3 is invalid
• Forgetting --create flag

5. You want to create a Kafka topic for a critical system that must not lose messages and should handle high load. Which topic creation settings are best?

hard

A. Partitions: 10, Replication factor: 3

B. Partitions: 1, Replication factor: 1

C. Partitions: 5, Replication factor: 1

D. Partitions: 3, Replication factor: 2

Solution

1. Step 1: Understand requirements for critical system

   High load needs many partitions for parallelism; no message loss needs high replication factor.

2. Step 2: Evaluate options

   Partitions: 10, Replication factor: 3 has 10 partitions (high load) and replication factor 3 (high safety). Others have fewer partitions or lower replication.

3. Final Answer:

   Partitions: 10, Replication factor: 3 -> Option A

4. Quick Check:

   High load + safety = many partitions + high replication [OK]

Hint: More partitions + higher replication = speed + safety [OK]

Common Mistakes:

• Choosing low replication for safety
• Choosing few partitions for high load
• Ignoring replication factor importance