Kafka Manager/UI tools - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kafka Manager topic list command?

You run the following command in Kafka Manager CLI to list topics in a cluster:

kafka-manager --list-topics --cluster my-cluster

Assuming the cluster has topics: orders, payments, users, what will be the output?

Kafka

kafka-manager --list-topics --cluster my-cluster

A

orders
payments
users

B [orders, payments, users]

C {orders, payments, users}

D Topic list: orders, payments, users

💡 Hint

Think about how CLI tools usually print lists line by line.

Kafka Manager CLI typically prints each topic name on its own line without brackets or extra text.

🧠 Conceptual

intermediate

Which UI tool allows you to monitor Kafka consumer lag visually?

You want to see how far behind your consumers are from the latest messages in Kafka. Which Kafka UI tool is designed to show consumer lag clearly?

A Kafka MirrorMaker

B Kafka Connect

C Kafka Streams

D Kafka Manager

💡 Hint

This tool is a web UI for managing and monitoring Kafka clusters.

Kafka Manager provides a web interface that shows consumer groups and their lag in real time.

🔧 Debug

advanced

Why does Kafka Manager fail to connect to the cluster?

You configured Kafka Manager with the cluster address but it shows connection errors. Which of these is the most likely cause?

Kafka

cluster.address=PLAINTEXT://kafka-broker:9092
zk.address=zk1:2181,zk2:2181

A Kafka Manager needs the broker IP, not hostname

B Kafka Manager requires ZooKeeper address, not just Kafka broker address

C Kafka Manager cannot connect because the port 9092 is blocked by firewall

D The cluster.address should use SSL protocol instead of PLAINTEXT

💡 Hint

Kafka Manager uses ZooKeeper to discover cluster metadata.

Kafka Manager connects to ZooKeeper to get cluster info; missing or wrong ZooKeeper address causes connection failure.

📝 Syntax

advanced

Identify the correct JSON format for Kafka Manager cluster config

Which JSON snippet correctly defines a Kafka cluster configuration for Kafka Manager?

A { name: "prod-cluster", zkHosts: "zk1:2181,zk2:2181", kafkaVersion: "2.8.0" }

B { 'name': 'prod-cluster', 'zkHosts': 'zk1:2181,zk2:2181', 'kafkaVersion': '2.8.0' }

C { "name": "prod-cluster", "zkHosts": "zk1:2181,zk2:2181", "kafkaVersion": "2.8.0" }

D { "name" => "prod-cluster", "zkHosts" => "zk1:2181,zk2:2181", "kafkaVersion" => "2.8.0" }

💡 Hint

JSON keys and string values must use double quotes.

Valid JSON requires double quotes for keys and string values; no single quotes or arrows.

🚀 Application

expert

How to automate topic creation with Kafka Manager API?

You want to create a new topic named 'logs' with 3 partitions and replication factor 2 using Kafka Manager's REST API. Which HTTP request body is correct?

A { "name": "logs", "numPartitions": 3, "replicationFactor": 2 }

B { "topic": "logs", "partitions": 3, "replicationFactor": 2 }

C { "topicName": "logs", "partitionsCount": 3, "replicas": 2 }

D { "topic": "logs", "partitions": "3", "replicationFactor": "2" }

💡 Hint

Check Kafka Manager API docs for exact field names and types.

Kafka Manager API expects 'name' for topic name, 'numPartitions' as integer, and 'replicationFactor' as integer.

Practice

1. What is the main purpose of Kafka Manager or similar UI tools for Kafka?

easy

A. To encrypt Kafka data during transmission

B. To provide a visual interface for monitoring Kafka clusters

C. To write Kafka messages automatically

D. To replace Kafka brokers with a graphical system

Solution

1. Step 1: Understand Kafka Manager's role

   Kafka Manager provides a web interface to monitor Kafka clusters visually.

2. Step 2: Compare options

   Options A, B, and C describe functions Kafka Manager does not perform.

3. Final Answer:

   To provide a visual interface for monitoring Kafka clusters -> Option B

4. Quick Check:

   Kafka Manager = Visual monitoring [OK]

Hint: Remember: Kafka Manager shows Kafka data visually [OK]

Common Mistakes:

• Thinking Kafka Manager replaces brokers
• Confusing monitoring with data encryption
• Assuming Kafka Manager writes messages automatically

2. Which command is typically used to start Kafka Manager UI after installation?

easy

A. java -jar kafka-manager.jar

B. kafka-server-start.sh

C. kafka-manager start

D. kafka-console-producer.sh

Solution

1. Step 1: Identify Kafka Manager start command

   Kafka Manager is a Java application started with java -jar kafka-manager.jar.

2. Step 2: Eliminate other options

   Options B and D start Kafka brokers or producers, not Kafka Manager. kafka-manager start is not a valid command.

3. Final Answer:

   java -jar kafka-manager.jar -> Option A

4. Quick Check:

   Start Kafka Manager = java -jar [OK]

Hint: Kafka Manager runs as a Java jar file [OK]

Common Mistakes:

• Using Kafka broker start commands instead
• Assuming a custom 'kafka-manager start' command exists
• Confusing producer commands with UI start

3. Given Kafka Manager is running and connected to a Kafka cluster, what will you see on its dashboard?

medium

A. List of topics, brokers, and consumer groups with their status

B. Only the raw Kafka log files

C. Source code of Kafka brokers

D. Encrypted Kafka messages

Solution

1. Step 1: Understand Kafka Manager dashboard content

   The dashboard shows topics, brokers, and consumer groups with their health and status.

2. Step 2: Check other options

   Raw logs, source code, or encrypted messages are not displayed on the dashboard.

3. Final Answer:

   List of topics, brokers, and consumer groups with their status -> Option A

4. Quick Check:

   Dashboard = Topics + Brokers + Consumers [OK]

Hint: Dashboard shows cluster components and status [OK]

Common Mistakes:

• Expecting raw logs or source code in UI
• Thinking encrypted messages are visible
• Confusing Kafka Manager with log viewer

4. You started Kafka Manager but the UI does not load in the browser. Which is the most likely cause?

medium

A. Kafka Manager requires a database to start

B. Kafka Manager is not connected to any Kafka cluster

C. Kafka topics are empty

D. Kafka Manager server is not running or listening on the expected port

Solution

1. Step 1: Check Kafka Manager server status

   If the UI does not load, the server might not be running or listening on the port.

2. Step 2: Evaluate other options

   Connection to Kafka cluster or empty topics won't prevent UI loading. Kafka Manager does not require a separate database to start.

3. Final Answer:

   Kafka Manager server is not running or listening on the expected port -> Option D

4. Quick Check:

   UI not loading = Server not running [OK]

Hint: Check if Kafka Manager server is running and port is open [OK]

Common Mistakes:

• Assuming empty topics block UI
• Thinking Kafka Manager needs a database to start
• Ignoring server running status

5. You want to monitor consumer lag using Kafka Manager UI. Which steps should you follow to set this up correctly?

hard

A. Install a separate lag monitoring tool and connect it to Kafka Manager

B. Modify Kafka broker configuration to enable lag monitoring

C. Add the Kafka cluster in Kafka Manager, then navigate to consumer groups to view lag metrics

D. Restart Kafka Manager with lag monitoring enabled via command line flag

Solution

1. Step 1: Add Kafka cluster to Kafka Manager

   You must first add your Kafka cluster details in Kafka Manager to connect and monitor it.

2. Step 2: Access consumer groups section

   Once connected, navigate to consumer groups in the UI to see lag metrics and consumer status.

3. Final Answer:

   Add the Kafka cluster in Kafka Manager, then navigate to consumer groups to view lag metrics -> Option C

4. Quick Check:

   Monitor lag = Add cluster + check consumer groups [OK]

Hint: Add cluster first, then check consumer groups for lag [OK]

Common Mistakes:

• Thinking lag monitoring needs separate tools
• Trying to enable lag via broker config
• Restarting Kafka Manager with flags instead of UI steps