about long-lived connection and message to send

[amqp-node]

about long-lived connection and message to send

[michaelklishin]

1. RabbitMQ connections are supposed to be long-lived
2. See amqp.node port of RabbitMQ tutorials.

[squaremo]

Yes, as Michael says, connections are supposed to be long-lived, as are channels.

In your code above, I think you're trying to have a single exported function that will send a message, and being stymied because you have promises rather than "real" values. You can dereference a promise more than once, so the easiest way to fix it is to phrase your function like this:

var q = 'task-queue';

var channel = connection.then(function(conn) {
    var ok = conn.createChannel();
    ok = ok.then(function(ch) {
        return ch.assertQueue(q, {durable: true})
            .then(function() { return ch; }); // swap
    });
    return ok;
});

exports.sendtomq=function(msg) {
    channel.then(function(ch) {
        ch.sendToQueue(q, new Buffer(msg), {persistent:true});
    });
};

The only tricky bit really is the swapping the assertQueue result for the channel itself (marked // swap), which I need to do because I want the channel value, but to synchronise on the queue being declared.

[jbasttdi]

Wow!thank you very much! what you said is really I want. After using your code,I can send my real message well.
Thanks again!

[jbasttdi]

Sorry,I have just a question.Need I to close the channel after sending the message?

exports.sendtomq=function(msg) {
        channel.then(function(ch) {
           ch.sendToQueue(q, new Buffer(msg), {persistent:true});
          }).ensure(function(){
              channel.close();  //? 
        });
 };

[squaremo]

Need I to close the channel after sending the message?

No; in fact you don't want to, usually, because it will stop you sending more messages with the channel. The original example code closes the channel because it's only sending one message before exiting.