无法接收来自 AWS iot 核心 MQTT 代理的消息

Question

我正在使用 mqtt_mutual_auth demo 订阅主题并收听传入消息。我使用 C SDK 进行订阅，使用 python SDK 发布消息。

订阅者代码

int main( int argc,
          char ** argv )
{
    int returnStatus = EXIT_SUCCESS;
    MQTTContext_t mqttContext = { 0 };
    NetworkContext_t networkContext = { 0 };
    OpensslParams_t opensslParams = { 0 };
    bool clientSessionPresent = false;
    struct timespec tp;

    ( void ) argc;
    ( void ) argv;

    /* Set the pParams member of the network context with desired transport. */
    networkContext.pParams = &opensslParams;

    /* Seed pseudo random number generator (provided by ISO C standard library) for
     * use by retry utils library when retrying failed network operations. */

    /* Get current time to seed pseudo random number generator. */
    ( void ) clock_gettime( CLOCK_REALTIME, &tp );
    /* Seed pseudo random number generator with nanoseconds. */
    srand( tp.tv_nsec );

    /* Initialize MQTT library. Initialization of the MQTT library needs to be
     * done only once in this demo. */
    returnStatus = initializeMqtt( &mqttContext, &networkContext );

    if( returnStatus == EXIT_SUCCESS )
    {
       
        /* Attempt to connect to the MQTT broker. If connection fails, retry after
            * a timeout. Timeout value will be exponentially increased till the maximum
            * attempts are reached or maximum timeout value is reached. The function
            * returns EXIT_FAILURE if the TCP connection cannot be established to
            * broker after configured number of attempts. */
        returnStatus = connectToServerWithBackoffRetries( &networkContext );

        if( returnStatus == EXIT_FAILURE )
        {
            /* Log error to indicate connection failure after all
                * reconnect attempts are over. */
            LogError( ( "Failed to connect to MQTT broker %.*s.",
                        AWS_IOT_ENDPOINT_LENGTH,
                        AWS_IOT_ENDPOINT ) );
        }
        else
        {
            /* If TLS session is established, execute Subscribe/Publish loop. */
            returnStatus = subscribePublishLoop( &mqttContext, &clientSessionPresent );
        }
        /* End TLS session, then close TCP connection. */
    }

    printf("Now wait for incoming publish \n");
    while(1)
    {
        sleep(1);
    }
    ( void ) Openssl_Disconnect( &networkContext );

    return returnStatus;
}

发布者代码

if __name__ == '__main__':
    # Spin up resources
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)

    mqttendpoint = "aqwfuwdaruggr-ats.iot.us-east-1.amazonaws.com"
    mqtt_connection = mqtt_connection_builder.mtls_from_path(
        endpoint = mqttendpoint,
        cert_filepath= "/home/mukesh/aws_mqtt/6fce06e56a-certificate.pem.crt",
        pri_key_filepath="/home/mukesh/aws_mqtt/6fce06e56a-private.pem.key",
        client_bootstrap=client_bootstrap,
        ca_filepath="/home/mukesh/aws_mqtt/AmazonRootCA1.crt",
        on_connection_interrupted=on_connection_interrupted,
        on_connection_resumed=on_connection_resumed,
        client_id=args.client_id,
        clean_session=False,
        keep_alive_secs=6)

    print("Connecting to {} with client ID '{}'...".format(
        mqttendpoint, args.client_id))

    connect_future = mqtt_connection.connect()

    # Future.result() waits until a result is available
    connect_future.result()
    print("Connected!")


    # Publish message to server desired number of times.
    # This step is skipped if message is blank.
    # This step loops forever if count was set to 0.
    if args.message:
        if args.count == 0:
            print ("Sending messages until program killed")
        else:
            print ("Sending {} message(s)".format(args.count))
        
        publish_topic = "device1/server/live"
        publish_count = 1
        while (publish_count <= args.count) or (args.count == 0):
            message = "{} [{}]".format(args.message, publish_count)
            print("Publishing message to topic '{}': {}".format(publish_topic, message))
            mqtt_connection.publish(
                topic=publish_topic,
                payload=message,
                qos=mqtt.QoS.AT_LEAST_ONCE)
            time.sleep(1)
            publish_count += 1

    # Disconnect
    print("Disconnecting...")
    disconnect_future = mqtt_connection.disconnect()
    disconnect_future.result()
    print("Disconnected!")

输出： 订阅者首先启动。 Publisher 在 10 秒后运行。

订阅者和发布者同时运行。

在第二种情况下，我只收到 10 条已发送消息中的一条消息。

任何人都可以请建议我出了什么问题。我已将选项设置为持久会话。所以我的理解是，aws iot 核心代理应该有一份未确认的 QOS1 消息的副本并将其发送给订阅者。