Pod placement

You can configure Pod placement for Hive metastores as described in Pod placement.

By default, the operator configures the following Pod placement constraints:

affinity:
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/name: hive
            app.kubernetes.io/instance: cluster-name
            app.kubernetes.io/component: metastore
        topologyKey: kubernetes.io/hostname
      weight: 70

In the example above cluster-name is the name of the HiveCluster custom resource that owns this Pod.

If OPA authorization is configured, the metastore Pods additionally prefer to run on the same Kubernetes nodes as the OPA Pods (weight 50):

affinity:
  podAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:
    - podAffinityTerm:
        labelSelector:
          matchLabels:
            app.kubernetes.io/name: opa
            app.kubernetes.io/instance: opa-cluster-name
            app.kubernetes.io/component: server
        topologyKey: kubernetes.io/hostname
      weight: 50

opa-cluster-name is the configMapName from spec.clusterConfig.authorization.opa, which by convention is the name of the OpaCluster.