Will and Testament on connection over Web Sockets

[javiermelendezc]

I'm currently trying to detect when a browser client connected to the broker loses connection due to network conditions

mqtt.connect("mqtt://xxxxxxxx:yyyy", {
            keepalive: 10,
            will: {
                topic: `test/status`,
                payload: "offline",
                qos: 0
            }
        })

Expected behavior

• When the client is configured, will message is set to "offline" and keep alive is set to 10 seconds
• When the client is connected, It publish a message with "online" payload
• When a client hasn't ping the broker for 10 seconds, the testament including the message "offline" is sent to clients subscribed to this topic.

Current behavior

• When I test it using Google Chrome and set the Network Condition to offline, the connection is not dropped, and the testament message is never sent to the subscribed clients
• The offline message is sent immediately (not after 10 seconds) to all subscribed clients when I close the client window

Is there any special consideration for will or testament when the connections is made over WS?

[YoDaMa]

@javiermelendezc let me try and help.

Is there any special consideration for will or testament when the connections is made over WS?

No. Connection over WS should be identical in nature to other protocols (regular mqtt, mqtts). So if there is inconsistencies, it is a bug.

First, could you provide a way to reproduce this? Including how you set up the Google Chrome broker, which is what I assume is receiving the LWT (last will and testament) message, and thus configuring it.

You can always check that LWT is being sent with the connect packet via the mqtt* debug logs. That will just check that the client is sending the LWT as part of the connect packet as per the MQTT spec. Other than that, how the broker handles LWT is based on the broker functionality.

[YoDaMa]

Closing due to inactivity.