CCDAK Questions and Answers

SpecificRecord is created from generated record classes

Keys are necessary if you require strong ordering or grouping for messages that share the same key. If you require that messages with the same key are always seen in the correct order, attaching a key to messages will ensure messages with the same key always go to the same partition in a topic. Kafka guarantees order within a partition, but not across partitions in a topic, so alternatively not providing a key - which will result in round-robin distribution across partitions - will not maintain such order.

Kafka replication mechanism makes it resilient to the scenarios where the broker lose data on disk, but can recover from replicating from other brokers. This makes Kafka amazing!

You will need to set the schemas.enable parameters for the converter to false for plain text with no schema.

Your Zookeeper cluster needs to have an odd number of servers, and must maintain a majority of servers up to be able to vote. Therefore, a 2N+1 zookeeper cluster can survive to N zookeeper being down, so here the right answer is N=2, 2*N+1=5

There is only one controller in a cluster at all times.

retention.ms can be configured at topic level while creating topic or by altering topic. It shouldn't be set at the broker level (log.retention.ms) as this would impact all the topics in the cluster, not just the one we are interested in

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.

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

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.

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

Message with no keys will be stored with round-robin strategy among partitions.

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

2181 - client port, 2888 - peer port, 3888 - leader port

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 herehttps://twitter.com/ijuma/status/1161303431501324293?s=09

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

acks=all means the leader will wait for all in-sync replicas to acknowledge the record. Also the min in-sync replica setting specifies the minimum number of replicas that need to be in-sync for the partition to remain available for writes.