:_mod-docs-content-type: CONCEPT

[id='config-node-pools-dependencies-{context}']
= Impact on racks when moving nodes from node pools

[role="_abstract"]
If rack awareness is enabled on a Kafka cluster, replicas can be spread across different racks, data centers, or availability zones.
When moving nodes from node pools, consider the implications on the cluster topology, particularly regarding rack awareness. 
Removing specific pods from node pools, especially out of order, may break the cluster topology or cause an imbalance in distribution across racks. 
An imbalance can impact both the distribution of nodes themselves and the partition replicas within the cluster.
An uneven distribution of nodes and partitions across racks can affect the performance and resilience of the Kafka cluster.

Plan the removal of nodes strategically to maintain the required balance and resilience across racks.
Use the `strimzi.io/remove-node-ids` annotation to move nodes with specific IDs with caution.
Ensure that configuration to spread partition replicas across racks and for clients to consume from the closest replicas is not broken. 

TIP: Use Cruise Control and the `KafkaRebalance` resource with the `RackAwareGoal` to make sure that replicas remain distributed across different racks.