Will (LWT)

Tip

For more information about the Last Will and Testament (LWT), refer to:

The settings below are modeled after HiveMQ client library's documentation for connect#will.

1. Topic

The MQTT topic to publish the last will message if the client disconnects unexpectedly.

All global variables are supported, e.g. you can use

wk/${USERNAME}/${APP_INSTANCE_ID}/will

Default: wk/will

2. Will QoS

Quality of Service (QoS) for the MQTT last will message. Determines the guarantee of message delivery in case of client disconnect.

Default: At Most Once (0)

3. Payload

The MQTT payload to send for the last will message if the client disconnects unexpectedly.

Default:

{
  "message": "Client has disconnected.",
  "username": "${USERNAME}",
  "appInstanceId": "${APP_INSTANCE_ID}"
}

4. Retain

Set to true to retain the last will message on the broker after it is sent.

Default: false

5. Message Expiry Interval (seconds)

The lifetime in seconds of the last will message on the broker after it is sent. A value of 0 means the message does not expire.

Default: 0

6. Will Delay Interval (seconds)

Time in seconds the broker will wait before sending the last will message after the client disconnects unexpectedly. A value of 0 means immediate delivery.