AMQP-CPP RabbitMQ async event based consumer not consuming anything

Question

I'm using the AMQ-CPP library (https://github.com/CopernicaMarketingSoftware/AMQP-CPP) to connect to an existing queue I've created but I'm unable to read anything. I've tested that the queue works using another library (https://github.com/alanxz/SimpleAmqpClient, it works and I consume messages), but it uses a polling approach and I need an event based one.

My code looks like (based on the provided example):

int main()
{
    auto *poll = EV_DEFAULT;

    // handler for libev (so we don't have to implement AMQP::TcpHandler!)
    AMQP::LibEvHandler handler(poll);

    // make a connection
    AMQP::TcpConnection connection(&handler, AMQP::Address("amqp://localhost/"));

    // we need a channel too
    AMQP::TcpChannel channel(&connection);

    // Define callbacks and start
    auto messageCb = [&channel](
            const AMQP::Message &message, uint64_t deliveryTag, 
            bool redelivered)
    {
        std::cout << "message received" << std::endl;
        // acknowledge the message
        channel.ack(deliveryTag);
        processMessage(message.routingKey(), message.body());
    };

    // callback function that is called when the consume operation starts
    auto startCb = [](const std::string &consumertag) {

        std::cout << "consume operation started: " << consumertag << std::endl;
    };

    // callback function that is called when the consume operation failed
    auto errorCb = [](const char *message) {

        std::cout << "consume operation failed" << std::endl;
    };

    channel.consume("domoqueue")
        .onReceived(messageCb)
        .onSuccess(startCb)
        .onError(errorCb);

    // run the poll
    ev_run(poll, 0);

    // done
    return 0;
}

I'm running the code in a Raspberry Pi having :

Linux raspberrypi 4.4.26-v7+ #915 SMP Thu Oct 20 17:08:44 BST 2016 armv7l GNU/Linux

What can be the problem? Probably I'm missing some configuration parameters for the queue... I've placed some debug traces and the channel creation does not take place. It blocks in the connection statement:

AMQP::TcpConnection connection(&handler, AMQP::Address("amqp://localhost/"));
cout << "I never show up" << endl;

// we need a channel too
AMQP::TcpChannel channel(&connection)

score 0 · Answer 1 · answered Mar 11 '17 at 12:00

I've found my problem: I wasn't using the declareQueue() method! In fact, I had to use it but specifying the following parameters (the same as I did when I created the queue manually):

AMQP::Table arguments;
arguments["x-message-ttl"] = 120 * 1000;

// declare the queue
channel.declareQueue("domoqueue", AMQP::durable + AMQP::passive, arguments).onSuccess(callback);

AMQP-CPP RabbitMQ async event based consumer not consuming anything

1 Answers1