Select the Kafka Streams joins that are always windowed joins.

1. A. KStream-KStream join
2. B. KTable-KTable join
3. C. KStream-GlobalKTable
4. D. KStream-KTable join

Correct Answer: A
Seehttps://docs.confluent.io/current/streams/developer-guide/dsl-api.html#joining

We want the average of all events in every five-minute window updated every minute. What kind of Kafka Streams window will be required on the stream?

1. A. Session window
2. B. Tumbling window
3. C. Sliding window
4. D. Hopping window

Correct Answer: D
A hopping window is defined by two propertiesthe window's size and its advance interval (aka "hop"), e.g., a hopping window with a size 5 minutes and an advance interval of 1 minute.

A consumer wants to read messages from a specific partition of a topic. How can this be achieved?

1. A. Call subscribe(String topic, int partition) passing the topic and partition number as the arguments
2. B. Call assign() passing a Collection of TopicPartitions as the argument
3. C. Call subscribe() passing TopicPartition as the argument

Correct Answer: B
assign() can be used for manual assignment of a partition to a consumer, in which case subscribe() must not be used. Assign() takes a collection of TopicPartition object as an argument https://kafka.apache.org/23/javadoc/org/apache/kafka/clients/consumer/KafkaConsumer.ht
ml#assign-java.util.Collection-

We have a store selling shoes. What dataset is a great candidate to be modeled as a KTable in Kafka Streams?

1. A. Money made until now
2. B. The transaction stream
3. C. Items returned
4. D. Inventory contents right now

Correct Answer: AC
Aggregations of stream are stored in table, whereas Streams must be modeled as a KStream to avoid data explosion

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

1. A. topic + partition + timestamp
2. B. topic + partition + offset
3. C. topic + timestamp

Correct Answer: B
(Topic,Partition,Offset) uniquely identifies a message in Kafka