Apache Kafka Practice

How do you ensure that data is written to more than one replica?

1. By reducing the number of replicas

2. By increasing the minimum in-sync replicas

3. By disabling leader election

4. By reducing message size

The correct answer is: By increasing the minimum in-sync replicas

Increasing the minimum in-sync replicas is essential for ensuring that data is reliably written to multiple replicas in a Kafka environment. This configuration parameter determines how many replicas must acknowledge a write operation before it is considered successful. By setting a higher minimum in-sync replicas, you are effectively mandating that a specific number of replicas must receive and confirm the write, ensuring that data is not just written to the leader but also to other designated replicas. This mechanism enhances data durability and availability because it protects against data loss. If the leader fails, however many in-sync replicas you have specified will continue to hold the last acknowledged state of the data. This behavior is critical in scenarios where high reliability and fault tolerance are needed. The other options do not contribute positively to writing data to multiple replicas. Reducing the number of replicas would lead to fewer copies of the data, and disabling leader election would remove the mechanism that gives one replica the responsibility for leading writes, which is counterproductive. Reducing message size also doesn't influence the replication factor or the guarantees provided by the replication mechanism itself.