code: function getLessLoaded(client, dataSource) {
    var ids = client.dataSources[dataSource]
      , nodes
      , node
  
    nodes = ids.map(id2client)
  
    function id2client(id) {
      return client.nodes[id]
    }
  
    node = nodes.reduce(lessLoaded)
  
    function lessLoaded(nodeA, nodeB) {
      if (nodeA.active < nodeB.active) {
        return nodeA
      }
      else {
        return nodeB
      }
    }
  
    return node
  }
docs: Bad-ass load-balancing
  
  @param {Druid} client Client instance
  @param {string} dataSource Data source name
  @returns {DruidNode}