Sink connectors in Kafka - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Kafka Connect sink connector configuration?

Given the following sink connector configuration snippet, what will be the value of the topics property after parsing?

Kafka

{
  "name": "my-sink-connector",
  "config": {
    "connector.class": "FileStreamSink",
    "tasks.max": "1",
    "topics": "topic1,topic2,topic3",
    "file": "/tmp/output.txt"
  }
}

A ["topic1 topic2 topic3"]

B ["topic1", "topic2", "topic3"]

C null

D "topic1,topic2,topic3"

💡 Hint

The topics property is a string listing topics separated by commas.

The 'topics' property in Kafka Connect sink connector config is a single string with comma-separated topic names. It is not automatically parsed into a list.

🧠 Conceptual

intermediate

Which option best describes the role of a Kafka Sink Connector?

What is the main purpose of a Kafka Sink Connector in Kafka Connect?

A To read data from external systems and write it into Kafka topics.

B To monitor Kafka broker health and performance.

C To read data from Kafka topics and write it into external systems.

D To manage Kafka cluster configurations automatically.

💡 Hint

Sink connectors move data out of Kafka.

Sink connectors consume data from Kafka topics and write it to external systems like databases, files, or other services.

🔧 Debug

advanced

Identify the error in this sink connector configuration snippet

This sink connector configuration is intended to write Kafka topic data to a file. What error will it cause?

Kafka

{
  "name": "file-sink",
  "config": {
    "connector.class": "FileStreamSink",
    "tasks.max": 1,
    "topics": ["my-topic"],
    "file": "/tmp/output.log"
  }
}

A Runtime error because 'tasks.max' must be a string

B SyntaxError due to JSON array in 'topics' property

C No error; configuration is valid

D Configuration error because 'file' path is invalid

💡 Hint

The 'topics' property expects a string, not an array.

The 'topics' property must be a comma-separated string, not a JSON array. Using an array causes a configuration parsing error.

📝 Syntax

advanced

Which option correctly defines a sink connector with exactly 3 tasks?

Select the valid JSON snippet that sets up a sink connector with 3 parallel tasks.

A { "name": "sink-connector", "config": { "connector.class": "JdbcSinkConnector", "tasks.max": "3", "topics": "orders", "connection.url": "jdbc:mysql://localhost:3306/shop" } }

B { "name": "sink-connector", "config": { "connector.class": "JdbcSinkConnector", "tasks.max": 3, "topics": "orders", "connection.url": "jdbc:mysql://localhost:3306/shop" } }

C { "name": "sink-connector", "config": { "connector.class": "JdbcSinkConnector", "tasks.max": "three", "topics": "orders", "connection.url": "jdbc:mysql://localhost:3306/shop" } }

D { "name": "sink-connector", "config": { "connector.class": "JdbcSinkConnector", "tasks.max": "3 tasks", "topics": "orders", "connection.url": "jdbc:mysql://localhost:3306/shop" } }

💡 Hint

The 'tasks.max' property must be a string representing a number.

In Kafka Connect configurations, numeric values like 'tasks.max' must be strings. Option A correctly uses "3" as a string.

🚀 Application

expert

How many tasks will run for this sink connector configuration?

Consider this sink connector config: { "name": "multi-task-sink", "config": { "connector.class": "FileStreamSink", "tasks.max": "5", "topics": "topicA,topicB" } } If the Kafka Connect cluster has only 3 worker nodes available, how many tasks will actually run?

A Only 1 task will run because FileStreamSink supports a single task.

B 5 tasks will run, distributed across the 3 workers.

C 3 tasks will run, limited by the number of available workers.

D No tasks will run due to configuration conflict.

💡 Hint

Some connectors limit the number of tasks regardless of 'tasks.max'.

The FileStreamSink connector supports only a single task regardless of the 'tasks.max' setting. So only 1 task runs.