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Flapping Detect Configuration

Flapping in EMQX refers to a situation where an MQTT client rapidly connects and disconnects from the broker in a short period. The flapping mechanism is to detect flapping clients and to disconnect the client from a connection.

For example, if you want to mark clients that make 15 connection attempts within a 1-minute window as flapping clients, and then ban the detected clients from connecting to EMQX for 5 minutes, you can work with the code below:

flapping_detect {
  max_count  =  15
  window_time  =  1m
  ban_time  =  5m


  • max_count is to set the maximum number of connection attempts allowed from a client within a specified time window (defined by window_time)
  • window_time is to set the time window in which the maximum number of connection attempts from a client are counted.
  • ban_time is to set the duration for which a client is banned from connecting to the EMQX after it has been detected as flapping.


You can also customize the settings via Dashboard by clicking Access Control -> Flapping Detect on the left navigation menu of the Dashboard. Once you configured these items with Dashboard, your settings will override the same configuration items in emqx.conf.


EMQX offers more configuration items to serve customized needs better. For details, see the EMQX Open Source Configuration Manual and EMQX Enterprise Configuration Manual for Enterprise.