CCDAK 시험 - Confluent실제시험문제와 답 - 150문항

Question No : 1

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

정답:
Explanation:
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 No : 2

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

정답:
Explanation:
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 No : 3

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

A.Store avro data
B.Enforce compatibility rules
C.Store schemas

정답:
Explanation:
Data is stored on brokers.

Question No : 4

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

정답:
Explanation:
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 No : 5

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

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

Question No : 6

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

정답:
Explanation:
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 No : 7

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

정답:
Explanation:
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 No : 8

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

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

Question No : 9

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

정답:
Explanation:
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.

Question No : 10

Which of the following is not an Avro primitive type?

A.string
B.long
C.int
D.date
E.null

정답:
Explanation:
date is a logical type

Question No : 11

If I want to send binary data through the REST proxy, it needs to be base64 encoded .
Which component needs to encode the binary data into base 64?

A.The Producer
B.The Kafka Broker
C.Zookeeper
D.The REST Proxy

정답:
Explanation:
The REST Proxy requires to receive data over REST that is already base64 encoded, hence it is the responsibility of the producer

Question No : 12

A Zookeeper ensemble contains 5 servers .
What is the maximum number of servers that can go missing and the ensemble still run?

A.3
B.4
C.2
D.1

정답:
Explanation:
majority consists of 3 zk nodes for 5 nodes zk cluster, so 2 can fail

Question No : 13

You are receiving orders from different customer in an "orders" topic with multiple partitions. Each message has the customer name as the key. There is a special customer named ABC that generates a lot of orders and you would like to reserve a partition exclusively for ABC. The rest of the message should be distributed among other partitions .
How can this be achieved?

A.Add metadata to the producer record
B.Create a custom partitioner
C.All messages with the same key will go the same partition, but the same partition may have messages with different keys. It is not possible to reserve
D.Define a Kafka Broker routing rule

정답:
Explanation:
A Custom Partitioner allows you to easily customise how the partition number gets computed from a source message.

Question No : 14

A consumer starts and has auto.offset.reset=latest, and the topic partition currently has data for offsets going from 45 to 2311. The consumer group has committed the offset 643 for the topic before.
Where will the consumer read from?

A.it will crash
B.offset 2311
C.offset 643
D.offset 45

정답:
Explanation:
The offsets are already committed for this consumer group and topic partition, so the property auto.offset.reset is ignored

Question No : 15

You have a consumer group of 12 consumers and when a consumer gets killed by the process management system, rather abruptly, it does not trigger a graceful shutdown of your consumer. Therefore, it takes up to 10 seconds for a rebalance to happen. The business would like to have a 3 seconds rebalance time .
What should you do? (select two)

A.Increase session.timeout.ms
B.Decrease session.timeout.ms
C.Increase heartbeat.interval.ms
D.decrease max.poll.interval.ms
E.increase max.poll.interval.ms
F.Decrease heartbeat.interval.ms

정답:
Explanation:
session.timeout.ms must be decreased to 3 seconds to allow for a faster rebalance, and the heartbeat thread must be quicker, so we also need to decrease heartbeat.interval.ms

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