Confluent Confluent Certifications CCDAK Questions & Answers

• Question 91:

  To continuously export data from Kafka into a target database, I should use

  A. Kafka Producer

  B. Kafka Streams C. Kafka Connect Sink

  D. Kafka Connect Source

  Correct Answer: C

  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 92:

  What isn't a feature of the Confluent schema registry?

  A. Store avro data

  B. Enforce compatibility rules

  C. Store schemas

  Correct Answer: A

  Data is stored on brokers.

• Question 93:

  A producer just sent a message to the leader broker for a topic partition. The producer used acks=1 and therefore the data has not yet been replicated to followers. Under which conditions will the consumer see the message?

  A. Right away

  B. When the message has been fully replicated to all replicas

  C. Never, the produce request will fail

  D. When the high watermark has advanced

  Correct Answer: D

  The high watermark is an advanced Kafka concept, and is advanced once all the ISR replicates the latest offsets. A consumer can only read up to the value of the High Watermark (which can be less than the highest offset, in the case of acks=1)

• Question 94:

  A consumer has auto.offset.reset=latest, and the topic partition currently has data for offsets going from 45 to 2311. The consumer group never committed offsets for the topic before. Where will the consumer read from?

  A. offset 2311

  B. offset 0

  C. offset 45

  D. it will crash

  Correct Answer: A

  Latest means that data retrievals will start from where the offsets currently end

• Question 95:

  You are running a Kafka Streams application in a Docker container managed by Kubernetes, and upon application restart, it takes a long time for the docker container to replicate the state and get back to processing the data. How can you improve dramatically the application restart?

  A. Mount a persistent volume for your RocksDB

  B. Increase the number of partitions in your inputs topic

  C. Reduce the Streams caching property

  D. Increase the number of Streams threads

  Correct Answer: A

  Although any Kafka Streams application is stateless as the state is stored in Kafka, it can take a while and lots of resources to recover the state from Kafka. In order to speed up recovery, it is advised to store the Kafka Streams state on a persistent volume, so that only the missing part of the state needs to be recovered.

• Question 96:

  In Kafka, every broker... (select three)

  A. contains all the topics and all the partitions

  B. knows all the metadata for all topics and partitions

  C. is a controller

  D. knows the metadata for the topics and partitions it has on its disk

  E. is a bootstrap broker

  F. contains only a subset of the topics and the partitions

  Correct Answer: BEF

  Kafka topics are divided into partitions and spread across brokers. Each brokers knows about all the metadata and each broker is a bootstrap broker, but only one of them is elected controller

• Question 97:

  What is true about partitions? (select two)

  A. A broker can have a partition and its replica on its disk

  B. You cannot have more partitions than the number of brokers in your cluster

  C. A broker can have different partitions numbers for the same topic on its disk

  D. Only out of sync replicas are replicas, the remaining partitions that are in sync are also leader

  E. A partition has one replica that is a leader, while the other replicas are followers

  Correct Answer: CE

  Only one of the replicas is elected as partition leader. And a broker can definitely hold many partitions from the same topic on its disk, try creating a topic with 12 partitions on one broker!

• Question 98:

  A topic "sales" is being produced to in the Americas region. You are mirroring this topic using Mirror Maker to the European region. From there, you are only reading the topic for analytics purposes. What kind of mirroring is this?

  A. Passive-Passive

  B. Active-Active

  C. Active-Passive

  Correct Answer: C

  This is active-passing as the replicated topic is used for read-only purposes only

• Question 99:

  Which of the following is not an Avro primitive type?

  A. string

  B. long

  C. int

  D. date

  E. null

  Correct Answer: D

  date is a logical type

• Question 100:

  An ecommerce website maintains two topics - a high volume "purchase" topic with 5 partitions and low volume "customer" topic with 3 partitions. You would like to do a stream- table join of these topics. How should you proceed?

  A. Repartition the purchase topic to have 3 partitions

  B. Repartition customer topic to have 5 partitions

  C. Model customer as a GlobalKTable

  D. Do a KStream / KTable join after a repartition step

  Correct Answer: C

  In case of KStream-KStream join, both need to be co-partitioned. This restriction is not applicable in case of join with GlobalKTable, which is the most efficient here.