Stream topology in Kafka - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a stream builder instance.

Kafka

StreamsBuilder builder = new [1]();

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

AStreamsBuilder

BKafkaStreams

CStreamConfig

DTopology

Attempts:

3 left

💡 Hint

Common Mistakes

Using KafkaStreams instead of StreamsBuilder.

Using Topology directly without builder.

StreamsBuilder is used to create the stream processing topology.

2fill in blank

medium

Complete the code to define a source stream from a topic named 'input-topic'.

Kafka

KStream<String, String> source = builder.stream([1]);

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

A"output-topic"

B"input-topic"

Cinput-topic

Dsource-topic

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the topic name.

Using the wrong topic name.

The stream method requires the topic name as a string literal.

3fill in blank

hard

Fix the error in the code to send the processed stream to an output topic.

Kafka

processedStream.to([1]);

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

A"output-topic"

BoutputTopic

Coutput-topic

DprocessedStream

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a variable name without quotes.

Passing the stream variable itself.

The to() method requires the topic name as a quoted string.

4fill in blank

hard

Fill both blanks to build and start the Kafka Streams application.

Kafka

Topology topology = builder.[1]();
KafkaStreams streams = new KafkaStreams(topology, [2]);
streams.start();

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

Abuild

Bstart

Cprops

Dconfig

Attempts:

3 left

💡 Hint

Common Mistakes

Using start() instead of build() on builder.

Passing config instead of props.

Use build() to create the topology and pass the properties object to KafkaStreams.

5fill in blank

hard

Fill all three blanks to create a stream, filter messages with value length > 5, and send to 'filtered-topic'.

Kafka

KStream<String, String> stream = builder.stream([1]);
KStream<String, String> filtered = stream.filter((key, value) -> value.[2]() > [3]);
filtered.to("filtered-topic");

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

A"input-topic"

Blength

C5

Dsize

Attempts:

3 left

💡 Hint

Common Mistakes

Using size() instead of length() for strings.

Not quoting the topic name.

We read from "input-topic", use length() to get string length, and filter values longer than 5.