Confluent CCDAK Confluent Certified Developer for Apache Kafka Certification Examination Exam Practice Test

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

ACLs are stored in Zookeeper node /kafka-acls/ by default.

Kafka logs are append-only and the data is immutable

Setting a group.id that's consistent across restarts will allow your consumers part of the same group to resume reading from where offsets were last committed for that group

One consumer per partition assignment will keep 5 consumers idle.

Dynamic topic configurations are maintained in Zookeeper.

With SSL, messages will need to be encrypted and decrypted, by being first loaded into the JVM, so you lose the zero copy optimization. See more information

Each broker must have a unique broker id and connect to the same zk ensemble and root zNode

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.

The Schema Registry stores all the schemas in the _schemas Kafka topic

Clients with new schema will be able to read records saved with old schema.

KSQL is not ANSI SQL compliant, for now there are no defined standards on streaming SQL languages

Consumers can set auto.offset.reset property to earliest to start consuming from beginning. For KSQL, SET 'auto.offset.reset'='earliest';

Replicas are passive - they don't handle produce or consume request. Produce and consume requests get sent to the node hosting partition leader.

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

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

Some messages may require multiple retries. If there are more than 1 requests in flight, it may result in messages received out of order. Note an exception to this rule is if you enable the producer settingenable.idempotence=true which takes care of the out of ordering case on its own.

Kafka Streams is a library for building streaming applications, specifically applications that transform input Kafka topics into output Kafka topics

Point-to-point (request-response) style will couple client to the server.

Since Confluent 5.4.0, Avro 1.9.1 is used. Since default value was added to enum complex type , the schema resolution changed from:

(<1.9.1) if both are enums:** if the writer's symbol is not present in the reader's enum, then an error is signalled. **(>=1.9.1) if both are enums:

if the writer's symbol is not present in the reader's enum and the reader has a default value, then that value is used, otherwise an error is signalled.

Sending a message with the null value is called a tombstone in Kafka and will ensure the log compacted topic does not contain any messages with the key K upon compaction

This will allow consumers to wait and receive more bytes in each fetch request.