What Are Kubernetes Labels and Annotations?

Kubernetes labels are key and value pairs (or metadata) attached to objects like pods, nodes, and namespaces. For more information, see Labels. Kubernetes annotations are similar to labels but can be small or large, structured or unstructured, and can include characters not permitted by labels. For more information, see Annotations.

MapR software attaches labels and annotations to nodes for scheduling pods on the nodes. You can modify the node labels and annotations to manage the nodes used by the data cluster and compute spaces. For more information, see Optional: Managing Nodes for the MapR Kubernetes Ecosystem.

During the validation phase of the bootstrapping process, on Kubernetes v1.13 and later, the bootstrapper attaches the following labels to the nodes on the Kubernetes cluster:
Label Description
mapr.com/exclusivecluster Specifies the data cluster for which to use the node. The value can be one of the following:
  • none – (default) Specifies to use the node for any data cluster pod in the Kubernetes environment.
  • <data cluster name> – Specifies to use the node only for the specified data cluster pods.
mapr.com/usenode Specifies whether or not to use the node to run compute operations. Possible values are true or false.
During the validation phase of the bootstrapping process, on Kubernetes v1.13 and later, the bootstrapinstall utility attaches the following annotations to the nodes on the Kubernetes cluster:
Annotation Description
mapr.com/bootstrapversion Specifies the version of the bootstrapinstall utility that was last run in the environment. The value should be 1.0.0 if you ran the bootstrapinstall utility associated with the current release.
mapr.com/fulldisklist Specifies the complete (used and available) list of disks, including the size of the disk, detected on the node.
mapr.com/hddlist Specifies the available list of HDD disks on the node.
mapr.com/nodetopology Specifies the topology of the node. The format of the topology is /<racknumber>/<nodename> where racknumber is rack1 by default.
mapr.com/nvmelist Specifies the available list of NVME disks on the node.
mapr.com/rack Specifies the rack number. The default value is rack1.
mapr.com/sddlist Specifies the list of available SDD disks on the node.
mapr.com/validationerror Specifies if there were errors during validation of the node. The value can be one of the following:
  • none – if there were no errors.
  • <errors> – if errors were generated.
mapr.com/validationstatus Specifies the status of the validation operation. The value can be one of the following:
  • validated – if the validation operation was completed successfully.
  • validating – if the validation operation is currently running.
    Note: Do not modify this property.