Standalone vs distributed mode in Kafka - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of Kafka standalone mode configuration

Consider a Kafka setup running in standalone mode with a single broker. What will be the output of the following command that lists topics?

Kafka

kafka-topics.sh --list --bootstrap-server localhost:9092

A Error: Could not connect to server

B No topics found

C List of all topics created on the single broker

D List of topics from all brokers in the cluster

💡 Hint

In standalone mode, there is only one broker managing all topics.

In standalone mode, Kafka runs a single broker that manages all topics. The command lists all topics on that broker.

🧠 Conceptual

intermediate

Difference in fault tolerance between standalone and distributed mode

Which statement correctly describes the fault tolerance difference between Kafka's standalone and distributed modes?

A Distributed mode allows replication of partitions across brokers for fault tolerance

B Standalone mode provides automatic failover using multiple brokers

C Standalone mode replicates data across multiple machines

D Distributed mode runs only one broker, so no fault tolerance

💡 Hint

Think about how Kafka handles data safety in a cluster.

Distributed mode uses multiple brokers and replicates partitions to provide fault tolerance. Standalone mode has only one broker and no replication.

🔧 Debug

advanced

Identify the error in distributed mode broker configuration

Given this broker configuration snippet for distributed mode, what error will occur? broker.id=0 listeners=PLAINTEXT://:9092 log.dirs=/tmp/kafka-logs zookeeper.connect=localhost:2181 Options:

A Zookeeper connection error due to wrong port

B Kafka broker starts normally and joins the cluster

C Syntax error in configuration file

D Kafka broker fails to start due to missing advertised.listeners

💡 Hint

In distributed mode, brokers must advertise their address to clients and other brokers.

Without advertised.listeners, clients cannot connect properly, causing startup issues in distributed mode.

📝 Syntax

advanced

Syntax error in standalone mode startup command

Which option shows the correct syntax to start Kafka in standalone mode using the command line?

A kafka-server-start.sh -daemon config/server.properties

B kafka-server-start.sh --config config/server.properties

C kafka-server-start.sh config/server.properties

D kafka-server-start.sh config/server.properties --standalone

💡 Hint

The -daemon flag runs Kafka in the background.

Option A correctly uses the -daemon flag to start Kafka with the given config file in standalone mode.

🚀 Application

expert

Choosing mode for a fault-tolerant Kafka deployment

You need to deploy Kafka for a critical application requiring high availability and fault tolerance. Which mode should you choose and why?

A Standalone mode, because it is simpler and faster to set up

B Distributed mode, because it supports partition replication and failover

C Standalone mode, because it uses less memory and CPU

D Distributed mode, because it runs on a single machine with multiple brokers

💡 Hint

Consider how Kafka handles failures and data safety.

Distributed mode allows multiple brokers with replicated partitions, providing fault tolerance and high availability.

Practice

1. What is the main purpose of running Kafka Connect in standalone mode?

easy

A. To run multiple workers for high scalability

B. To run Kafka Connect in a single process for simple or testing use

C. To enable fault tolerance across multiple machines

D. To connect Kafka with distributed databases automatically

Solution

1. Step 1: Understand standalone mode context

   Standalone mode runs Kafka Connect in one process, suitable for simple or testing scenarios.

2. Step 2: Compare with distributed mode

   Distributed mode runs multiple workers for scalability and fault tolerance, unlike standalone mode.

3. Final Answer:

   To run Kafka Connect in a single process for simple or testing use -> Option B

4. Quick Check:

   Standalone mode = single process for testing [OK]

Hint: Standalone = single process, simple use [OK]

Common Mistakes:

• Confusing standalone with distributed mode
• Thinking standalone supports fault tolerance
• Assuming standalone is for large scale pipelines

2. Which of the following is the correct command to start Kafka Connect in distributed mode?

easy

A. kafka-connect.sh start-standalone

B. connect-standalone.sh config/connect-standalone.properties

C. kafka-connect.sh start-distributed

D. connect-distributed.sh config/connect-distributed.properties

Solution

1. Step 1: Identify the script for distributed mode

   The script connect-distributed.sh is used to start Kafka Connect in distributed mode.

2. Step 2: Confirm the configuration file

   The configuration file config/connect-distributed.properties is the standard config for distributed mode.

3. Final Answer:

   connect-distributed.sh config/connect-distributed.properties -> Option D

4. Quick Check:

   Distributed mode uses connect-distributed.sh [OK]

Hint: Distributed mode uses connect-distributed.sh script [OK]

Common Mistakes:

• Using connect-standalone.sh for distributed mode
• Mixing config files between modes
• Assuming kafka-connect.sh is a valid command

3. Given the following scenario: You start Kafka Connect with connect-standalone.sh and add two connectors. What will happen if the process crashes?

medium

A. Both connectors will automatically restart on another worker

B. Connectors will continue running without interruption

C. The connectors will stop and require manual restart

D. Kafka Connect will switch to distributed mode automatically

Solution

1. Step 1: Understand standalone mode fault tolerance

   Standalone mode runs in a single process without fault tolerance or automatic recovery.

2. Step 2: Consequence of process crash

   If the process crashes, connectors stop and need manual restart because no other worker is available.

3. Final Answer:

   The connectors will stop and require manual restart -> Option C

4. Quick Check:

   Standalone mode lacks automatic recovery [OK]

Hint: Standalone mode needs manual restart after crash [OK]

Common Mistakes:

• Assuming automatic failover in standalone mode
• Thinking distributed mode starts automatically
• Believing connectors run independently of the process

4. You configured Kafka Connect in distributed mode but notice that only one worker is running and no failover happens. What is the likely cause?

medium

A. You started Kafka Connect with connect-standalone.sh instead of connect-distributed.sh

B. You did not configure the Kafka cluster correctly

C. You forgot to add connectors to the worker

D. Distributed mode does not support multiple workers

Solution

1. Step 1: Check the startup script used

   If connect-standalone.sh is used, only one worker runs without failover, even if config is for distributed mode.

2. Step 2: Understand distributed mode requirements

   Distributed mode requires starting with connect-distributed.sh to run multiple workers and enable failover.

3. Final Answer:

   You started Kafka Connect with connect-standalone.sh instead of connect-distributed.sh -> Option A

4. Quick Check:

   Wrong startup script causes single worker [OK]

Hint: Use connect-distributed.sh to run multiple workers [OK]

Common Mistakes:

• Assuming config alone enables distributed mode
• Believing distributed mode runs with standalone script
• Ignoring startup script importance

5. You have a data pipeline that must handle high volume and remain available even if one worker fails. Which Kafka Connect mode should you choose and why?

hard

A. Distributed mode, because it supports multiple workers and fault tolerance

B. Standalone mode, because it is simpler to configure

C. Standalone mode, because it automatically restarts connectors on failure

D. Distributed mode, because it runs connectors in a single process

Solution

1. Step 1: Analyze pipeline requirements

   High volume and availability require scalability and fault tolerance.

2. Step 2: Match requirements to Kafka Connect modes

   Distributed mode runs multiple workers and supports fault tolerance, meeting these needs.

3. Final Answer:

   Distributed mode, because it supports multiple workers and fault tolerance -> Option A

4. Quick Check:

   High volume + fault tolerance = distributed mode [OK]

Hint: Choose distributed mode for scalability and fault tolerance [OK]

Common Mistakes:

• Choosing standalone for high availability
• Thinking standalone auto-restarts connectors
• Misunderstanding distributed mode runs single process