Confluent Certified Developer CCDAK Preparation Guides

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Confluent Certified Developer CCDAK preparation guides are the best material for you to pass. Each candidate has 90 minutes to finish the CCDAK exam. The exam format is multiple choice. The CCDAK exam cost is $150. Free Confluent Certified Developer CCDAK exam preparation guides are available below.

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1. Where are the dynamic configurations for a topic stored?

In Zookeeper

In an internal Kafka topic __topic_configuratins

In server.properties

On the Kafka broker file system

2. What happens when broker.rack configuration is provided in broker configuration in Kafka cluster?

You can use the same broker.id as long as they have different broker.rack configuration

Replicas for a partition are placed in the same rack

Replicas for a partition are spread across different racks

Each rack contains all the topics and partitions, effectively making Kafka highly available

3. What is the disadvantage of request/response communication?

Scalability

Reliability

Coupling

Cost

4. is KSQL ANSI SQL compliant?

Yes

5. When using plain JSON data with Connect, you see the following error messageorg.apache.kafka.connect.errors.DataExceptionJsonDeserializer with schemas.enable requires "schema" and "payload" fields and may not contain additional fields .

How will you fix the error?

Set key.converter, value.converter to JsonConverter and the schema registry url

Use Single Message Transforms to add schema and payload fields in the message

Set key.converter.schemas.enable and value.converter.schemas.enable to false

Set key.converter, value.converter to AvroConverter and the schema registry url

6. There are 3 brokers in the cluster. You want to create a topic with a single partition that is resilient to one broker failure and one broker maintenance .

What is the replication factor will you specify while creating the topic?

7. Two consumers share the same group.id (consumer group id). Each consumer will

Read mutually exclusive offsets blocks on all the partitions

Read all the data on mutual exclusive partitions

Read all data from all partitions

8. A consumer starts and has auto.offset.reset=none, and the topic partition currently has data for offsets going from 45 to 2311. The consumer group has committed the offset 10 for the topic before.

Where will the consumer read from?

offset 45

offset 10

it will crash

offset 2311

9. A kafka topic has a replication factor of 3 and min.insync.replicas setting of 2 .

How many brokers can go down before a producer with acks=all can't produce?

10. Where are KSQL-related data and metadata stored?

Kafka Topics

Zookeeper

PostgreSQL database

Schema Registry

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11. You want to sink data from a Kafka topic to S3 using Kafka Connect. There are 10 brokers in the cluster, the topic has 2 partitions with replication factor of 3 .

How many tasks will you configure for the S3 connector?

12. To enhance compression, I can increase the chances of batching by using

acks=all

linger.ms=20

batch.size=65536

max.message.size=10MB

13. How can you gracefully make a Kafka consumer to stop immediately polling data from Kafka and gracefully shut down a consumer application?

Call consumer.wakeUp() and catch a WakeUpException

Call consumer.poll() in another thread

Kill the consumer thread

14. StreamsBuilder builder = new StreamsBuilder();

KStream<String, String> textLines = builder.stream("word-count-input");

KTable<String, Long> wordCounts = textLines

.mapValues(textLine -> textLine.toLowerCase())

.flatMapValues(textLine -> Arrays.asList(textLine.split("W+")))

.selectKey((key, word) -> word)

.groupByKey()

.count(Materialized.as("Counts"));

wordCounts.toStream().to("word-count-output", Produced.with(Serdes.String(), Serdes.Long()));

builder.build();

What is an adequate topic configuration for the topic word-count-output?

max.message.bytes=10000000

cleanup.policy=delete

compression.type=lz4

cleanup.policy=compact

15. Where are the ACLs stored in a Kafka cluster by default?

Inside the broker's data directory

Under Zookeeper node /kafka-acl/

In Kafka topic __kafka_acls

Inside the Zookeeper's data directory

16. What kind of delivery guarantee this consumer offers?

while (true) {

ConsumerRecords<String, String> records = consumer.poll(100);

try {

consumer.commitSync();

} catch (CommitFailedException e) { log.error("commit failed", e)

}

for (ConsumerRecord<String, String> record records)

{

System.out.printf("topic = %s, partition = %s, offset = %d, customer = %s, country = %s

",

record.topic(), record.partition(), record.offset(), record.key(), record.value());

}

}

Exactly-once

At-least-once

At-most-once

17. The exactly once guarantee in the Kafka Streams is for which flow of data?

Kafka => Kafka

Kafka => External

External => Kafka

18. You are using JDBC source connector to copy data from a table to Kafka topic. There is one connector created with max.tasks equal to 2 deployed on a cluster of 3 workers .

How many tasks are launched?

19. You want to perform table lookups against a KTable everytime a new record is received from the KStream .

What is the output of KStream-KTable join?

KTable

GlobalKTable

You choose between KStream or KTable

Kstream

20. You are doing complex calculations using a machine learning framework on records fetched from a Kafka topic. It takes more about 6 minutes to process a record batch, and he consumer enters rebalances even though it's still running .

How can you improve this scenario?

Increase max.poll.interval.ms to 600000

Increase heartbeat.interval.ms to 600000

Increase session.timeout.ms to 600000

Add consumers to the consumer group and kill them right away

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21. Which actions will trigger partition rebalance for a consumer group? (select three)

Increase partitions of a topic

Remove a broker from the cluster

Add a new consumer to consumer group

A consumer in a consumer group shuts down Add a broker to the cluster

22. Which of the following setting increases the chance of batching for a Kafka Producer?

Increase batch.size

Increase message.max.bytes

Increase the number of producer threads

Increase linger.ms

23. What data format isn't natively available with the Confluent REST Proxy?

avro

binary

protobuf

json

24. You are using JDBC source connector to copy data from 2 tables to two Kafka topics. There is one connector created with max.tasks equal to 2 deployed on a cluster of 3 workers .

How many tasks are launched?

25. To import data from external databases, I should use

Confluent REST Proxy

Kafka Connect Sink

Kafka Streams

Kafka Connect Source

26. What is a generic unique id that I can use for messages I receive from a consumer?

topic + partition + timestamp

topic + partition + offset

topic + timestamp

27. What happens if you write the following code in your producer?

producer.send(producerRecord).get()

Compression will be increased

Throughput will be decreased

It will force all brokers in Kafka to acknowledge the producerRecord

Batching will be increased

28. Compaction is enabled for a topic in Kafka by setting log.cleanup.policy=compact .

What is true about log compaction?

After cleanup, only one message per key is retained with the first value

Each message stored in the topic is compressed

Kafka automatically de-duplicates incoming messages based on key hashes

After cleanup, only one message per key is retained with the latest value Compaction changes the offset of messages

29. Which of these joins does not require input topics to be sharing the same number of partitions?

KStream-KTable join

KStream-KStream join

KStream-GlobalKTable

KTable-KTable join

30. How often is log compaction evaluated?

Every time a new partition is created

Every time a segment is closed

Every time a message is sent to Kafka

Every time a message is flushed to disk

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31. A Zookeeper ensemble contains 3 servers.

Over which ports the members of the ensemble should be able to communicate in default configuration? (select three)

2181

3888

443

2888

9092

32. A client connects to a broker in the cluster and sends a fetch request for a partition in a topic. It gets an exception Not Leader For Partition Exception in the response .

How does client handle this situation?

Get the Broker id from Zookeeper that is hosting the leader replica and send request to it

Send metadata request to the same broker for the topic and select the broker hosting the leader replica

Send metadata request to Zookeeper for the topic and select the broker hosting the leader replica

Send fetch request to each Broker in the cluster

33. If I supply the setting compression.type=snappy to my producer, what will happen? (select two)

The Kafka brokers have to de-compress the data

The Kafka brokers have to compress the data

The Consumers have to de-compress the data

The Consumers have to compress the data

The Producers have to compress the data

34. If I produce to a topic that does not exist, and the broker setting auto.create.topic.enable=true, what will happen?

Kafka will automatically create the topic with 1 partition and 1 replication factor

Kafka will automatically create the topic with the indicated producer settings num.partitions and default.replication.factor

Kafka will automatically create the topic with the broker settings num.partitions and default.replication.factor

Kafka will automatically create the topic with num.partitions=#of brokers and replication.factor=3

35. How will you read all the messages from a topic in your KSQL query?

KSQL reads from the beginning of a topic, by default.

KSQL reads from the end of a topic. This cannot be changed.

Use KSQL CLI to set auto.offset.reset property to earliest

36. The kafka-console-consumer CLI, when used with the default options

uses a random group id

always uses the same group id

does not use a group id

37. A producer is sending messages with null key to a topic with 6 partitions using the DefaultPartitioner. Where will the messages be stored?

Partition 5

Any of the topic partitions

The partition for the null key

Partition 0

38. Which of the following Kafka Streams operators are stateless? (select all that apply)

map

filter

flatmap

branch

groupBy

aggregate

39. Suppose you have 6 brokers and you decide to create a topic with 10 partitions and a replication factor of 3. The brokers 0 and 1 are on rack A, the brokers 2 and 3 are on rack B, and the brokers 4 and 5 are on rack C. If the leader for partition 0 is on broker 4, and the first replica is on broker 2, which broker can host the last replica? (select two)

40. Your topic is log compacted and you are sending a message with the key K and value null .

What will happen?

The broker will delete all messages with the key K upon cleanup

The producer will throw a Runtime exception

The broker will delete the message with the key K and null value only upon cleanup

The message will get ignored by the Kafka broker

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41. A kafka topic has a replication factor of 3 and min.insync.replicas setting of 1 .

What is the maximum number of brokers that can be down so that a producer with acks=all can still produce to the topic?

42. You have a Kafka cluster and all the topics have a replication factor of 3. One intern at your company stopped a broker, and accidentally deleted all the data of that broker on the disk .

What will happen if the broker is restarted?

The broker will start, and other topics will also be deleted as the broker data on the disk got deleted

The broker will start, and won't be online until all the data it needs to have is replicated from other leaders

The broker will crash

The broker will start, and won't have any data. If the broker comes leader, we have a data loss

43. A consumer application is using KafkaAvroDeserializer to deserialize Avro messages .

What happens if message schema is not present in AvroDeserializer local cache?

Throws SerializationException

Fails silently

Throws DeserializationException

Fetches schema from Schema Registry

44. In the Kafka consumer metrics it is observed that fetch-rate is very high and each fetch is small .

What steps will you take to increase throughput?

Increase fetch.max.wait

Increase fetch.max.bytes

Decrease fetch.max.bytes

Decrease fetch.min.bytes

Increase fetch.min.bytes

45. In Avro, removing or adding a field that has a default is a __ schema evolution

full

backward

breaking

forward

Confluent Certified Developer CCDAK Preparation Guides

Confluent Certified Developer CCDAK Preparation Guides

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