anchor.diff:    connected to if `search.remote.node.attr` is set to `gateway`.
   
   `search.remote.connect`::
  - By default, any node in the cluster can act as a cross-cluster client and connect to remote clusters.
  - The `search.remote.connect` setting can be set to `false` (defaults to `true`) to prevent certain nodes from
  - connecting to remote clusters. Cross-cluster search requests must be sent to a node that is allowed to act as a
  - cross-cluster client.
  +
  +  By default, any node in the cluster can act as a cross-cluster client and
  +  connect to remote clusters. The `search.remote.connect` setting can be set
  +  to `false` (defaults to `true`) to prevent certain nodes from connecting to
  +  remote clusters. Cross-cluster search requests must be sent to a node that
  +  is allowed to act as a cross-cluster client.
   
   
  
positive.code: --------------------------------
  <1> `cluster_one` and `cluster_two` are arbitrary cluster aliases representing the connection to each cluster.
  These names are subsequently used to distinguish between local and remote indices.
  
  [float]
  === Using cross cluster search
  
negative.code: [[modules-cross-cluster-search]]
  == Cross Cluster Search
  
  beta[]
  
  The _cross cluster search_ feature allows any node to act as a federated client across
  multiple clusters. In contrast to the <<modules-tribe,tribe node>> feature, a  cross cluster search node won't
  join the remote cluster, instead it connects to a remote cluster in a light fashion in order to execute
  federated search requests.
  
  Cross cluster search works by configuring a remote cluster in the cluster state and connecting only to a
  limited number of nodes in the remote cluster. Each remote cluster is referenced by a name and a list of seed nodes.
  Those seed nodes are used to discover nodes in the remote cluster which are eligible as _gateway nodes_.
  Each node in a cluster that has remote clusters configured connects to one or more _gateway nodes_ and uses
  them to federate search requests to the remote cluster.
  
  [float]
  === Configuring Cross Cluster Search
  
  Remote clusters can be specified globally using <<cluster-update-settings,cluster settings>>
  (which can be updated dynamically), or local to individual nodes using the
  `elasticsearch.yml` file.
  
  If a remote cluster is configured via `elasticsearch.yml` only the nodes with
  that configuration will be able to connect to the remote cluster. In other
  words, federated search requests will have to be sent specifically to those
  nodes. Remote clusters set via the <<cluster-update-settings,cluster settings API>>
  will be available on every node in the cluster.
  
  [WARNING]
  This feature was added in Elasticsearch `v5.3` and requires gateway eligible nodes to be on `v5.3` onwards.
  