hub: 
  clientid: Client ID of Client connection Hub. It should not be empty when cleansession is false . 
  address: [Must] Address of Client connection Hub. 
  username: [Must] User name of Client connection Hub. 
  password:If you use account password, you must fill out the password of Client connection  Hub, outherwise you do not need to fill out it. 
  ca: If certificate two-way authentication is adopted, the CA certificate path of Client  connection Hub should be filled out. 
  key: If certificate two-way authentication is adopted, the client private key path of Client  connection Hub should be filled out. 
  cert: If certificate two-way authentication is adopted, the client public key path of Client  connection Hub should be filled out. 
  timeout: Default value: 30s, Time-out period of Client connection Hub 
  interval: Default value: 1m, Maximum interval time for reconnection of Client connection Hub, increasing to the maximum value from 500 microseconds by doubling. 
  keepalive: Default value: 10m, Holding time of Client connection Hub 
  cleansession: Default value: false, Session persistence of Client connection Hub or not. 
  validatesubs: Default value: false, Client checks Hub subscription result or not; exit after reporting of error in case of subscription failure discovered. 
  buffersize: Default value: 10, Size of memory queue for Client to send messages to Hub ; message loss can be caused by abnormal exit, and the messages with QoS = 1 will depend  on Hub to resend. 
timer: timer association attributes 
  interval: timer module timing interval 
publish: 
  topic: Timing result published to the subject of Hub 
  #Payload supports golang template, and currently, two types of functions are supported: Time and Rand 
  payload: "{ \"datetime\": {{.Time.Now}},\"timestamp\": {{.Time.NowUnix}},\"timestampNano\": {{.Time.NowUnixNano}},\"random1\": {{.Rand.Int}},\"random2\": {{.Rand.Int63}},\"random3\": {{.Rand.Intn 10}},\"random4\": {{.Rand.Float64}},\"random5\": {{.Rand.Float64n 60}}, \"anyString\": \"inputString\" }" 
logger: Log configuration item 
  path: It is empty by default, i.e., no file is printed; if a file is appointed, it will be output to file. 
  level: Default value: Info, log level, supporting debug, info, warn and error. 
  format: Default value: Text, log print format, supporting text and json 
  age: 
    max: Default value: 15, Maximum number of days a log file is retained 
  size: 
    max: Default value: 50, Log file size limit, unit MB. 
  backup: 
    max: Default value: 15, Maximum number of log files retained.