Geo-replication strategies in Kafka - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of Kafka MirrorMaker 2 configuration

Given the following MirrorMaker 2 configuration snippet, what will be the output in the target cluster after replication?

Kafka

clusters = {
  "source": {"bootstrap.servers": "source.kafka:9092"},
  "target": {"bootstrap.servers": "target.kafka:9092"}
}
tasks.max = 2

replication.policy.class = "org.apache.kafka.connect.mirror.DefaultReplicationPolicy"

# Topics to replicate
replication.topics = "topicA,topicB"

# MirrorMaker 2 replicates topicA and topicB from source to target

# Assume topicA has 3 partitions with messages 1 to 3, topicB has 2 partitions with messages 10 to 11

# What messages will appear in target cluster topics after MirrorMaker 2 runs?

A topicA with partitions 0-2 containing messages 10 to 11, topicB with partitions 0-1 containing messages 1 to 3

B topicA with partitions 0-2 containing messages 1 to 3, topicB with partitions 0-1 containing messages 10 to 11

C topicA and topicB will be empty in target cluster

D Only topicA will be replicated with messages 1 to 3; topicB will not be replicated

💡 Hint

MirrorMaker 2 replicates specified topics with their partitions and messages from source to target.

MirrorMaker 2 replicates the specified topics (topicA and topicB) from the source cluster to the target cluster, preserving partitions and messages.

🧠 Conceptual

intermediate

Understanding active-active geo-replication

Which statement best describes active-active geo-replication in Kafka?

A Replication happens only during off-peak hours to reduce network load.

B Data is replicated only from one primary cluster to multiple secondary clusters without writes on secondaries.

C Multiple clusters can accept writes and replicate data to each other, enabling multi-region active writes.

D Data is replicated from secondary clusters back to the primary cluster only.

💡 Hint

Active-active means all clusters can write data and replicate.

Active-active geo-replication allows multiple Kafka clusters in different regions to accept writes and replicate data to each other, supporting multi-region active writes.

🔧 Debug

advanced

Identify the error in MirrorMaker 2 replication config

What error will occur when running MirrorMaker 2 with this configuration snippet? replication.policy.class = "org.apache.kafka.connect.mirror.NonExistentPolicy" clusters = { "source": {"bootstrap.servers": "source.kafka:9092"}, "target": {"bootstrap.servers": "target.kafka:9092"} } replication.topics = "topicX"

A ClassNotFoundException for org.apache.kafka.connect.mirror.NonExistentPolicy

B No error, MirrorMaker 2 will replicate topicX correctly

C Timeout error connecting to source.kafka:9092

D SyntaxError in configuration file

💡 Hint

Check if the replication policy class exists in Kafka MirrorMaker 2.

MirrorMaker 2 requires a valid replication policy class. Using a non-existent class causes a ClassNotFoundException at startup.

📝 Syntax

advanced

Correct syntax for MirrorMaker 2 topic whitelist

Which option correctly sets MirrorMaker 2 to replicate only topics starting with 'logs-'?

A replication.topics.regex = "logs-.*"

B replication.topics = "logs-*"

C replication.topics = logs-*

D replication.topics.regex = logs-*

💡 Hint

MirrorMaker 2 uses regex property for pattern matching topics.

To replicate topics by pattern, MirrorMaker 2 uses replication.topics.regex with a valid regex string.

🚀 Application

expert

Designing a geo-replication strategy for low latency writes

You have two Kafka clusters in different continents. You want to allow applications in both regions to write data with minimal latency and keep data synchronized. Which geo-replication strategy should you choose?

A Active-passive replication with MirrorMaker 2 replicating from primary to secondary cluster only

B No replication, rely on manual data export/import between clusters

C Single cluster with global clients connecting remotely

D Active-active replication with multi-master clusters replicating data bidirectionally

💡 Hint

Consider latency and write availability in multiple regions.

Active-active replication allows both clusters to accept writes locally, reducing latency and replicating data bidirectionally to keep clusters synchronized.