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    Monitor MQTT Errors

    Note: This is an obsolete legacy page, superseded by content at Using MQTT with AirVantage

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    MQTT ‘errors’ topic

    When using the MQTT protocol to connect an embedded application to AirVantage, developers can subscribe to the {IMEI or SN}/errors MQTT topic, to get notified when a message contains an invalid payload.

    Monitor JSON errors

    Suppose you publish a message on topic {IMEI or SN}/messages/json with an invalid JSON format:

    // Invalid JSON - timestamp should be a string
{ 12346013564 : { "temperature" : 42 } }

    The JSON payload is invalid because the timestamp is expected to be a JSON string (format described in AirVantage Reserved topics page).

    You can subscribe to {IMEI or SN}/errors to receive a message, with a payload containing 3 lines in text format (separated by \n):

    • the topic on which the initial message was published
    • the payload of the message
    • a diagnostic message describing the error

    With the previous request, you would receive:

    {IMEI or SN}/messages/json
{ 12346013564 : { "temperature" : 42 } }
invalid character '1' looking for beginning of object key string

    Monitor CBOR errors

    Suppose you publish on {IMEI or SN}/messages/ts the CBOR corresponding to the following JSON message:

    // Invalid CBOR, a timestamp is missing in the sample
{
    "h" : [             "x", "y", "z", "lat",    "long",   , "speed" ],

    "f" : [ 0.01,        1,   1 ,  1,   1000000,  1000000,   1       ],

    "s" : [ 0,   2,   0,   49455177, 537743,    100 ]
}

    Format described in MQTT compressed format for time series page.

    You can subscribe to {IMEI or SN}/errors to receive a message, with a payload containing 3 lines of text (separated by \n):

    • the topic on which the message was published
    • the payload of the message (encoded as UTF-8)
    • a diagnostic message describing the error

    With the previous request, you would receive:

    {IMEI or SN}/messages/tz
[Encoded payload]
Not enough CBOR samples at line 0 ; found 6, expected 7. 
See https://doc.airvantage.net/av/reference/hardware/protocols/mqtt-ts/

    More on MQTT

    MQTT.org

    Eclipse Paho

    MQTT standard at OASIS

    Understand the MQTT protocol

    Getting started with MQTT

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