Kafka Connect architecture - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a Kafka Connect source connector class.

Kafka

public class MySourceConnector extends [1] { }

Drag options to blanks, or click blank then click option'

AKafkaProducer

BSinkConnector

CConnectorConfig

DSourceConnector

Attempts:

3 left

💡 Hint

Common Mistakes

Using SinkConnector instead of SourceConnector

Extending KafkaProducer which is unrelated to connectors

The class must extend SourceConnector to implement a source connector in Kafka Connect.

2fill in blank

medium

Complete the code to start the Kafka Connect worker with the correct configuration.

Kafka

Worker worker = new Worker("worker1", config, [1]);

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Aherder

Bnull

Cconnector

Dproducer

Attempts:

3 left

💡 Hint

Common Mistakes

Passing null instead of herder

Passing unrelated objects like producer or connector

The Worker constructor requires a herder object to manage connectors and tasks.

3fill in blank

hard

Fix the error in the connector configuration property key.

Kafka

props.put("[1]", "my-connector");

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Aname

Bconnector.name

Cconnector.class

Dconnector.id

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'connector.name' which is invalid

Using 'connector.id' which is not a valid property

The correct property key for naming a connector is name.

4fill in blank

hard

Fill both blanks to create a task configuration map with the correct keys.

Kafka

Map<String, String> taskConfig = new HashMap<>();
taskConfig.put("[1]", "my-task");
taskConfig.put("[2]", "com.example.MyTask");

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Atask.name

Btask.class

Cname

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'task.name' instead of 'name'

Using 'class' instead of 'task.class'

The task configuration uses name for the task name and task.class for the task class.

5fill in blank

hard

Fill all three blanks to complete the connector's taskConfigs method.

Kafka

public List<Map<String, String>> taskConfigs(int maxTasks) {
    List<Map<String, String>> configs = new ArrayList<>();
    for (int i = 0; i < [1]; i++) {
        Map<String, String> config = new HashMap<>();
        config.put("[2]", "task-" + i);
        config.put("[3]", this.config.get("connector.class"));
        configs.add(config);
    }
    return configs;
}

Drag options to blanks, or click blank then click option'

AmaxTasks

Bname

Ctask.class

DmaxTaskCount

Attempts:

3 left

💡 Hint

Common Mistakes

Using an undefined variable instead of maxTasks

Using wrong keys like 'task.name' or 'class'

The loop runs up to maxTasks. Each task config uses name for the task name and task.class for the task class.

Practice

1. What is the main role of a Kafka Connect worker in the Kafka Connect architecture?

easy

A. To run connectors and tasks that move data between Kafka and external systems

B. To store Kafka topic data permanently

C. To produce messages to Kafka topics

D. To manage Kafka broker configurations

Solution

1. Step 1: Understand Kafka Connect components

   Kafka Connect architecture includes workers, connectors, and tasks. Workers run connectors and tasks.

2. Step 2: Identify worker's role

   Workers execute connectors and tasks to move data between Kafka and external systems.

3. Final Answer:

   To run connectors and tasks that move data between Kafka and external systems -> Option A

4. Quick Check:

   Worker = runs connectors/tasks [OK]

Hint: Workers run connectors and tasks to move data [OK]

Common Mistakes:

• Confusing workers with Kafka brokers
• Thinking workers store data permanently
• Mixing up producers and workers

2. Which of the following is the correct way to start Kafka Connect in standalone mode using the command line?

easy

A. connect-distributed.sh worker.properties connector.properties

B. connect-standalone.sh worker.properties connector.properties

C. kafka-server-start.sh connect-standalone.properties

D. kafka-connect-start.sh standalone.properties

Solution

1. Step 1: Recall Kafka Connect startup commands

   Standalone mode uses connect-standalone.sh with worker and connector config files.

2. Step 2: Match correct command syntax

   connect-standalone.sh worker.properties connector.properties matches the correct command format: connect-standalone.sh worker.properties connector.properties

3. Final Answer:

   connect-standalone.sh worker.properties connector.properties -> Option B

4. Quick Check:

   Standalone mode uses connect-standalone.sh [OK]

Hint: Standalone mode uses connect-standalone.sh command [OK]

Common Mistakes:

• Using connect-distributed.sh for standalone mode
• Confusing Kafka broker start scripts with Connect scripts
• Wrong file names or missing config files

3. Given the following Kafka Connect distributed mode configuration snippet:

{
  "name": "my-source-connector",
  "config": {
    "connector.class": "FileStreamSource",
    "tasks.max": "2",
    "file": "/tmp/input.txt",
    "topic": "test-topic"
  }
}

What does the tasks.max setting control?

medium

A. The maximum number of tasks to run for this connector

B. The maximum number of Kafka brokers to connect

C. The maximum size of each message sent

D. The maximum number of topics to read from

Solution

1. Step 1: Understand the tasks.max parameter

   In Kafka Connect, tasks.max sets how many tasks a connector can run in parallel.

2. Step 2: Apply to given config

   Here, tasks.max is 2, so the connector can run up to 2 tasks to increase throughput.

3. Final Answer:

   The maximum number of tasks to run for this connector -> Option A

4. Quick Check:

   tasks.max = max tasks per connector [OK]

Hint: tasks.max limits parallel tasks for connector [OK]

Common Mistakes:

• Confusing tasks.max with broker count
• Thinking it limits message size
• Assuming it controls topic count

4. You have a distributed Kafka Connect cluster but notice that connectors are not starting tasks as expected. Which of the following is the most likely cause?

medium

A. The connector configuration file is missing the tasks.max property

B. Kafka brokers are offline

C. The worker.properties file is empty

D. The connector class name is misspelled in the configuration

Solution

1. Step 1: Analyze why tasks don't start

   If connectors don't start tasks, a common cause is an invalid connector class name.

2. Step 2: Check other options

   Missing tasks.max defaults to 1 task, so not likely cause. Brokers offline cause other errors. Empty worker.properties would prevent worker start. Misspelled connector class prevents task creation.

3. Final Answer:

   The connector class name is misspelled in the configuration -> Option D

4. Quick Check:

   Misspelled connector class blocks tasks [OK]

Hint: Check connector class spelling if tasks don't start [OK]

Common Mistakes:

• Assuming missing tasks.max stops tasks
• Ignoring connector class name correctness
• Not verifying worker config completeness

5. You want to build a fault-tolerant data pipeline using Kafka Connect that can scale horizontally and recover from worker failures. Which Kafka Connect mode should you choose and why?

hard

A. Standalone mode, because it is simpler and easier to configure

B. Distributed mode, because it requires no configuration files

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

D. Standalone mode, because it automatically balances tasks across workers

Solution

1. Step 1: Understand Kafka Connect modes

   Standalone mode runs a single worker, no fault tolerance or scaling. Distributed mode runs multiple workers, supports scaling and fault tolerance.

2. Step 2: Match requirements to mode

   For fault tolerance and horizontal scaling, distributed mode is required.

3. Final Answer:

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

4. Quick Check:

   Fault tolerance needs distributed mode [OK]

Hint: Use distributed mode for scaling and fault tolerance [OK]

Common Mistakes:

• Choosing standalone for fault tolerance
• Thinking standalone balances tasks
• Believing distributed mode needs no config