For testing, I have created a client with clean sessin = false and setWill(WILL_TOPIC, WILL_MSG.getBytes(), 1, true); and ran the App. Later, i set setWill(WILL_TOPIC, WILL_MSG.getBytes(), 1, false); when i run the App, i receive the previously reatined LWT messages. How to stop receiving them?
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Amrmsmb
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You aren't receiving LWT messages as such, but a retained message. To clear a retained message, send a zero length retained message to the same topic. For example, with the Paho Python client you would do:
client.publish(WILL_TOPIC, payload=None, retain=True)
ralight
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hi,do you think if the client called "disconnect", would that help to clear the "LWT" retained? – Amrmsmb Nov 14 '14 at 16:57
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No, nothing apart from publishing an empty payload to the same topic will clear a retained message – hardillb Nov 14 '14 at 17:07
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You could send a CONNECT message with “CleanSession=false” and “Will=true”, and sends an empty WILLTOPIC message
check this section 6.3
Amrmsmb
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You linked the MQTT-SN specification which is different from standard MQTT, so this won't help the OP much. In case of MQTT-SN this will delete the WILL, though :) – Dominik Obermaier Nov 14 '14 at 16:46
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