How are the seeds selected when cross cluster search is used?

[YuWatanabe]

Hello .

When multiple seeds are defined per cluster, how are seeds selected to send one _search_shards?

I am assuming active-backup is used instead of load balancing such as round-robin.

My settings are below.

1.Cluster Settings API

curl -XGET -H  'Content-Type: application/json'  localhost:9200/_cluster/settings?pretty                               {
  "persistent" : {
    "search" : {
      "remote" : {
        "asia-northeast1-b" : {
          "seeds" : [
            "es-asia-northeast1-b-1:9300",
            "es-asia-northeast1-b-2:9300",
            "es-asia-northeast1-b-3:9300"
          ]
        }
      }
    }
  },
  "transient" : { }
}

2.Remote Info API

 curl -XGET -H  'Content-Type: application/json'  localhost:9200/_remote/info?pretty
{
  "asia-northeast1-b" : {
    "seeds" : [
      "10.146.0.3:9300",
      "10.146.0.5:9300",
      "10.146.0.6:9300"
    ],
    "http_addresses" : [
      "10.146.0.3:9200",
      "10.146.0.6:9200",
      "10.146.0.5:9200"
    ],
    "connected" : true,
    "num_nodes_connected" : 3,
    "max_connections_per_cluster" : 3,
    "initial_connect_timeout" : "30s",
    "skip_unavailable" : false
  }
}