+"空闲%"
        },
        tooltip: {},
        legend: {
          data: [name]
        },
        xAxis: {
          data: xDatas
        },
        yAxis: {},
        series: [{
          name: '空闲',
          type: 'line',
          data: yDatas
        }]
      };
      chart.setOption(option)
      return option;
    }
    //
    function initMQTT() {
      // Create a client instance
      var client = new Paho.Client("broker的地址", 8083, "/mqtt", getRandomString());

      // set callback