Confluent Confluent Certifications CCDAK Questions & Answers

• Question 121:

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

  A. KStream-KTable join

  B. KStream-KStream join

  C. KStream-GlobalKTable

  D. KTable-KTable join

  Correct Answer: C

  GlobalKTables have their datasets replicated on each Kafka Streams instance and therefore no repartitioning is required

• Question 122:

  How often is log compaction evaluated?

  A. Every time a new partition is created

  B. Every time a segment is closed

  C. Every time a message is sent to Kafka

  D. Every time a message is flushed to disk

  Correct Answer: B

  Log compaction is evaluated every time a segment is closed. It will be triggered if enough data is "dirty" (see dirty ratio config)

• Question 123:

  Compaction is enabled for a topic in Kafka by setting log.cleanup.policy=compact. What is true about log compaction?

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

  B. Each message stored in the topic is compressed

  C. Kafka automatically de-duplicates incoming messages based on key hashes

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

  Correct Answer: D

  Log compaction retains at least the last known value for each record key for a single topic partition. All compacted log offsets remain valid, even if record at offset has been compacted away as a consumer will get the next highest offset.

• Question 124:

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

  A. topic + partition + timestamp

  B. topic + partition + offset

  C. topic + timestamp

  Correct Answer: B

  (Topic,Partition,Offset) uniquely identifies a message in Kafka

• Question 125:

  What happens if you write the following code in your producer? producer.send(producerRecord).get()

  A. Compression will be increased

  B. Throughput will be decreased

  C. It will force all brokers in Kafka to acknowledge the producerRecord

  D. Batching will be increased

  Correct Answer: B

  Using Future.get() to wait for a reply from Kafka will limit throughput.

• Question 126:

  To import data from external databases, I should use

  A. Confluent REST Proxy

  B. Kafka Connect Sink

  C. Kafka Streams

  D. Kafka Connect Source

  Correct Answer: D

  Kafka Connect Sink is used to export data from Kafka to external databases and Kafka Connect Source is used to import from external databases into Kafka.

• Question 127:

  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?

  A. 6

  B. 1

  C. 2

  D. 3

  Correct Answer: C

  we have two tables, so the max number of tasks is 2

• Question 128:

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

  A. avro

  B. binary

  C. protobuf

  D. json

  Correct Answer: C

  Protocol buffers isn't a natively supported type for the Confluent REST Proxy, but you may use the binary format instead

• Question 129:

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

  A. Increase partitions of a topic

  B. Remove a broker from the cluster

  C. Add a new consumer to consumer group

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

  Correct Answer: ACD

  Rebalance occurs when a new consumer is added, removed or consumer dies or paritions increased.

• Question 130:

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

  A. Increase batch.size

  B. Increase message.max.bytes

  C. Increase the number of producer threads

  D. Increase linger.ms

  Correct Answer: D

  linger.ms forces the producer to wait to send messages, hence increasing the chance of creating batches