ClickHouse/tests/integration/test_interserver_dns_retires/configs/remote_servers.xml

<clickhouse>
  <remote_servers>
    <cluster_missing_replica>
      <shard>
        <replica>
          <!-- note: this one doesn't actually exist -->
          <host>node1</host>
          <port>9000</port>
          <default_database>r0</default_database>
        </replica>
        <replica>
          <host>node2</host>
          <port>9000</port>
          <default_database>r0</default_database>
        </replica>
      </shard>
      <shard>
        <replica>
          <host>node3</host>
          <port>9000</port>
          <default_database>r0</default_database>
        </replica>
        <replica>
          <host>node3</host>
          <port>9000</port>
          <default_database>r0</default_database>
        </replica>
      </shard>
    </cluster_missing_replica>
  </remote_servers>
</clickhouse>