Understanding Kubernetes: Part 25 Affinity and Anti-Affinity

📢 If you’ve been following our Kubernetes series 2025, welcome back! For new readers, check out Part 24: Taints and Tolerations

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What is Node Affinity?

Node Affinity is a rule that ensures Pods are scheduled on specific nodes based on defined labels.

What is Pod Affinity and Anti-Affinity?

• Pod Affinity ensures that Pods are scheduled close to other Pods based on label selectors.
• Pod Anti-Affinity prevents Pods from being scheduled on the same nodes or within a failure domain.

Use Cases

Affinity and Anti-Affinity are useful in various scenarios:

1. Node Affinity

• Ensuring that workloads requiring SSD storage run on nodes labeled with storage=ssd.
• Running GPU-intensive workloads on nodes labeled gpu=true.

2. Pod Affinity

• Ensuring that microservices communicate efficiently by scheduling them on the same node.
• Keeping interdependent applications (e.g…