Pod Placement

You can configure Pod placement for HDFS nodes as described in Pod Placement.

Default Pod placement constraints for name nodes:

affinity:
  podAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 20
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/component: namenode
            app.kubernetes.io/instance: hdfs
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 70

Default Pod placement constraints for data nodes:

affinity:
  podAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 20
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/component: datanode
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 70

Default Pod placement constraints for journal nodes:

affinity:
  podAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 20
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/component: journalnode
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/name: hdfs
        topologyKey: kubernetes.io/hostname
      weight: 70

In the examples above cluster-name is the name of the HDFS custom resource that owns this Pod.