How to change the number of replicas of a Kafka topic?

Question

After a Kafka topic has been created by a producer or an administrator, how would you change the number of replicas of this topic?

Answer 1

Łukasz Dumiszewski's answer is correct but manually generating that file is a bit hard. Luckily there are some easy ways to achieve what @Łukasz Dumiszewski said.

• If you are using kafka-manager tool, from version 2.0.0.2 you can change the replication factor in Generate Partition Assignment section in a topic view. Then you should click on Reassign Partitions to apply the generated partition assignment (if you select a different replication factor, you will get a warning but you can click on Force Reassign afterward).

• If you have ruby installed you can use this helper script

• If you prefer nodejs you can generate the file with this gist too.