Reassignment examples

A collection of examples that demonstrate how users can modify the proposed configuration file generated by the kafka-reassign-partitions.

There are multiple ways to modify the configuration file. The following list of examples shows how a user can modify a proposed configuration and what these changes do.

Suppose that the kafka-reassign-partitions tool generated the following proposed reassignment configuration:

{"version":1,
 "partitions":
   [{"topic":"mytopic1","partition":0,"replicas":[1,2],"log_dirs":["any","any"]}]}

Now let's look at how this reassignment configuration has to be changed in different reassignment scenarios.

Reassign partitions between brokers

To reassign partitions from one broker to another, change the broker ID specified in replicas. For example:

{"topic":"mytopic1","partition":0,"replicas":[5,2],"log_dirs":["any","any"]}

This reassignment configuration moves partition mytopic1-0 from broker 1 to broker 5.

Reassign partitions to another log directory on the same broker

To reassign partitions between log directories on the same broker, change the appropriate any entry to an absolute path. For example:

{"topic":"mytopic1","partition":0,"replicas":[1,2],"log_dirs":["/log/directory1","any"]}

This reassignment configuration moves partition mytopic1-0 to the /log/directory1 log directory.

Reassign partitions between log directories across multiple brokers

To reassign partitions between log directories across multiple brokers, change the broker ID specified in replicas and the appropriate any entry to an absolute path. For example:

{"topic":"mytopic1","partition":0,"replicas":[5,2],"log_dirs":["/log/directory1","any"]}

This reassignment configuration moves partition mytopic1-0 to /log/directory1 on broker 5.

Change partition assignment order (elect a new leader)

To change the ordering of the partition assignment list, change the order of the brokers in replicas. For example:

{"topic":"mytopic1","partition":0,"replicas":[2,1],"log_dirs":["any","any"]}

This reassignment configuration elects broker 2 as the new leader.