Assigning roles to nodes

An OpenSearch node can fulfill different roles, e.g. it can manage the operation of a cluster or store and search data.

All nodes are defined under the role nodes. The role configuration already defaults to a set of node roles:

nodes:
  config:
    nodeRoles:
      - cluster_manager
      - data
      - ingest
      - remote_cluster_client

If you deploy a cluster with the following specification, then 3 replicas with the roles cluster_manager, data, ingest and remote_cluster_client are deployed:

nodes:
  roleGroups:
    default:
      replicas: 3

In a production cluster, you probably want to assign different roles to the nodes. This can be achieved by creating multiple role groups and configuring their node roles. The node roles configured at the role group level override the ones from the role level.

For instance, if you want to deploy the sample cluster from the OpenSearch documentation that has one dedicated cluster manager node, one dedicated coordinating node and two data nodes, you could configure the role groups as follows:

nodes:
  roleGroups:
    cluster-manager:
      config:
        nodeRoles:
          - cluster_manager
      replicas: 1
    coordinating:
      config:
        nodeRoles:
          - coordinating_only
      replicas: 1
    data:
      config:
        nodeRoles:
          - data
          - ingest
      replicas: 2

The following roles are currently supported by the operator:

  • cluster_manager

  • coordinating_only

  • data

  • ingest

  • remote_cluster_client

  • search

  • warm

We refer to the OpenSearch documentation for an explanation of the roles.