Rebalancing behavior in Kafka - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the consumer group ID for Kafka consumer.

Kafka

props.put("group.id", [1]);

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

A"localhost"

B"topic-name"

C"kafka-server"

D"my-group"

Attempts:

3 left

💡 Hint

Common Mistakes

Using server or topic names instead of a group ID.

Leaving the group.id property unset.

The group.id property sets the consumer group ID, which is required for rebalancing behavior.

2fill in blank

medium

Complete the code to subscribe the consumer to a topic named "orders".

Kafka

consumer.subscribe(Collections.[1]("orders"));

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AemptyList

BsingletonList

Csingleton

DlistOf

Attempts:

3 left

💡 Hint

Common Mistakes

Using emptyList which subscribes to no topics.

Using singleton which is not a method in Collections.

The subscribe method expects a collection of topics. singletonList creates a list with one element.

3fill in blank

hard

Fix the error in the rebalance listener method signature.

Kafka

consumer.subscribe(topics, new ConsumerRebalanceListener() {
    @Override
    public void [1](Collection<TopicPartition> partitions) {
        // handle partitions revoked
    }

    @Override
    public void onPartitionsAssigned(Collection<TopicPartition> partitions) {
        // handle partitions assigned
    }
});

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AonPartitionsRevoked

BonRebalance

CpartitionsRevoked

DpartitionsAssigned

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names like partitionsRevoked or onRebalance.

Confusing assigned and revoked methods.

The correct method name is onPartitionsRevoked to handle revoked partitions during rebalance.

4fill in blank

hard

Fill both blanks to commit offsets synchronously after partitions are assigned.

Kafka

public void onPartitionsAssigned(Collection<TopicPartition> partitions) {
    consumer.[1]();
    consumer.[2](offsets);
}

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AcommitSync

BcommitAsync

Cseek

Dpoll

Attempts:

3 left

💡 Hint

Common Mistakes

Using poll instead of commit methods.

Calling seek instead of commit.

commitSync() commits the current offsets synchronously; commitSync(offsets) commits specific offsets synchronously.

5fill in blank

hard

Fill all three blanks to implement a rebalance listener that commits offsets and seeks to correct positions.

Kafka

consumer.subscribe(topics, new ConsumerRebalanceListener() {
    @Override
    public void onPartitionsRevoked(Collection<TopicPartition> partitions) {
        consumer.[1]();
    }

    @Override
    public void onPartitionsAssigned(Collection<TopicPartition> partitions) {
        for (TopicPartition partition : partitions) {
            consumer.[2](partition, offsets.get(partition));
        }
        consumer.[3]();
    }
});

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

AcommitSync

Bseek

CcommitAsync

Dpoll

Attempts:

3 left

💡 Hint

Common Mistakes

Using poll instead of commit or seek.

Not committing offsets before rebalance.

On partitions revoked, commitSync is called to save offsets. On assigned, seek moves to saved offsets, then commitAsync commits asynchronously.