postwait / node-amqp Goto Github PK

Hello,

I just npm install amqp and when I do npm list I get following modules [email protected]
I tried to run following code which comes bundled with source ...

I get following error ..

q.bind.addCallback undefined...

Any idea ? Is it supposed to work ?

Any sample code which works with this package or I should install some other package

Thanks
Rajan

var amqp = require('./amqp');

var connection = amqp.createConnection({host: 'localhost'});

connection.addListener('close', function (e) {
if (e) {
throw e;
} else {
console.log('connection closed.');
}
});

connection.addListener('ready', function () {
console.log("connected to " + connection.serverProperties.product);

var exchange = connection.exchange('clock', {type: 'fanout'});

var q = connection.queue('my-events-receiver');

q.bind(exchange, "*").addCallback(function () {
console.log("publishing message");
exchange.publish("message.json", {hello: 'world', foo: 'bar'});
exchange.publish("message.text", 'hello world', {contentType: 'text/plain'});
});

q.subscribe(function (m) {
console.log("--- Message (" + m.deliveryTag + ", '" + m.routingKey + "') ---");
console.log("--- contentType: " + m.contentType);

m.addListener('data', function (d) {
  console.log(d);
});

m.addListener('end', function () {
  m.acknowledge();
  console.log("--- END (" + m.deliveryTag + ", '" + m.routingKey + "') ---");
});

});
});

I have the following code for a consumer:

var amqp = require('amqp');

var conn = amqp.createConnection({host: 'localhost'});

conn.on('ready', function() {
  var exc = conn.exchange('exchange-name');
  var q = conn.queue('queue-name', function(queue) {
    console.log(q.name);
  });
  q.bind('exchange-name', 'routingkey');
});

The queue is not durable and should be created by this consumer.

This fails on the server with the following error in the rabbitmq log:

"connection <0.1173.0>, channel 2 - error:
{amqp_error,not_found,"no queue 'queue-name' in vhost '/'",'queue.bind'}"

RabbitMQ version is 2.4.1

Hi!

I was getting started with Node.Js and interest in testing the speed of queuing with RabbitMQ. However i got stuck with this issue connecting. I will be investigating more into it, but perhaps it is something i overlooked or something else in the code.

Basically i get this error which shows a fairly large frame size. I also have a PHP implementation and the frame size is set to the default rabbitMQ size of 131072 and it seems fine.

execute: AMQP

got frame: [65,19793,1342243080]


events.js:47
        throw new Error("Uncaught, unspecified 'error' event.");
              ^
Error: Uncaught, unspecified 'error' event.
    at Connection.emit (events.js:47:15)
    at AMQPParser.onError (/nodeJS_stuff/node_modules/amqp/amqp.js:839:12)
    at AMQPParser.throwError (/nodeJS_stuff/node_modules/amqp/amqp.js:145:25)
    at AMQPParser.execute (/nodeJS_stuff/node_modules/amqp/amqp.js:181:18)
    at Connection.<anonymous> (/nodeJS_stuff/node_modules/amqp/amqp.js:851:12)
    at Connection.emit (events.js:64:17)
    at Connection._onReadable (net.js:672:14)
    at IOWatcher.onReadable [as callback] (net.js:177:10)

My only initial guess is somehow the frame length in the header position is different thus reading the wrong length value, but i am not well versed in rabbitMQ packets yet.

Using NodeJs v0.4.12
RabbitMQ Server: 1.7.2 default config values, running on ubuntu.

Code:
var conn = amqp.createConnection({url: rabbitUrl()}); conn.on('ready', setup);

For me it seems like a code issue at least with the settings/config i am using considering the PHP client works fine.

Not sure what to do about this one, or even whether something needs to be done: JavaScript can only represent integers exactly up to 2^53, while AMQP has two types that are integers encoded in 64 bits (longlong and timestamp).

A timestamp is used only once in the protocol, as a timestamp for messages; this has no formal meaning, but taking it as say, Unix time, 2^53 is probably well after the technological singularity.

The type longlong is only used for delivery tags, in a few places, which are in effect serial numbers and (in RabbitMQ at least) scoped to channels. Reaching 2^53 messages on a single channel would be impressive.

Possibly more of a problem is that the parsing and serialisation code use bitshifts with operands outside that defined in JavaScript. Putting the 64-bit integer problem aside, these should really use straight multiplication and division (yes even for 32-bit numbers; bitshifts are defined on twos-complement integers).

...\node_modules\amqp\amqp.js:833
parser.execute(data);
^
TypeError: Cannot call method 'execute' of null
at Connection. (C:\Users\tshrestha\GSMarquee\node-web\main\node_modules\amqp\amqp.js:833:12)
at Connection.emit (events.js:67:17)
at TCP.onread (net.js:347:14)

Looking at amqp.js
parser.onError = function(e) {
self.end();
self.emit("error", e);
self.emit("close");
parser = null;
};

self.addListener('end', function () {
self.end();
// in order to allow reconnects, have to clear the
// state.
parser = null;
});

So, the parser is reset to null on end or error. But somehow a 'data' event arrived afterwards:
self.addListener('data', function (data) {
parser.execute(data); //<--this is line #833
});

I'm writing a small test and, when there are no subscribers in the exchange while using mandatory delivery mode, I get an an uncaught exception, despite me catching that event.

Code snippets

var msgDeliveryOptions = {
    mandatory: true,
    deliveryMode: 2          // persistent = 2, non-persistent = 1
};

var exchange = connection.exchange('acacio.topic', null, function(e) { util.puts(e.name); });
exchange.publish('test', msg, msgDeliveryOptions);
exchange.on('basicReturn', exchangeError);

function exchangeError(err) {
  util.puts(JSON.stringify(err, null, 2));
  util.puts('I got it!');
}

OUTPUT:

{
  "replyCode": 312,
  "replyText": "NO_ROUTE",
  "exchange": "acacio.topic",
  "routingKey": "test"
}
I got it!
Warning: Uncaught basicReturn: {"replyCode":312,"replyText":"NO_ROUTE","exchange":"acacio.topic","routingKey":"test"}

I stumbled upon an annoying bug trying to use the passive option of the queue.
The library doesn't properly handle the
'NOT_FOUND - no queue 'xxxxx' in vhost '/'' event, rendering passive useless.

using 0.1.1

I've created virtual host "dev" on my rabbit instance. I cannot connect to queue for anything other than default "/" virtual host. I do not get an error if I connect to any queue on "/" vhost.

var queueName = "devqueue";
 var connection = amqp.createConnection({'host': 'localhost', 'port': 5672, 'vhost' : 'dev'});

 connection.on('ready', function() {
        var args = {'exclusive': false, 'autoDelete': false, 'durable' : true};
        var q = connection.queue(queueName , args);
        q.bind('#');
 });

yields the error

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: INTERNAL_ERROR
    at Connection._onMethod (/opt/apps/amqp/scripts/node_modules/amqp/amqp.js:995:15)
    at AMQPParser.onMethod (/opt/apps/amqp/scripts/node_modules/amqp/amqp.js:811:12)
    at AMQPParser._parseMethodFrame (/opt/apps/amqp/scripts/node_modules/amqp/amqp.js:456:10)
    at AMQPParser.execute (/opt/apps/amqp/scripts/node_modules/amqp/amqp.js:206:20)
    at Connection.<anonymous> (/opt/apps/amqp/scripts/node_modules/amqp/amqp.js:851:12)
    at Connection.emit (events.js:67:17)
    at TCP.onread (net.js:329:14)

The default content type for JSON is text/json. According to RFC 4627 application/json is the correct content type. Can the default be changed, or does that break backwards compatibility?

If you want to compute messages only depending on their routing key, we are used to publish an empty string in the message.
I have looked at AMQP v0-9-1, and I didn't see anywhere that we shouldn't do that.
In addition, it is possible in Python with pika, and RabbitMQ handles such messages, but they are not consumed by node-amqp. So if I set the ack option to true in the declaration of my queue, the consumption of messages stop as no callback is triggered on the reception of such messages, and so I don't have possibility to ack those messages.

Of course, I can change my applications to avoid the publication of empty string messages, but I would like to know if is it a choice or if there is a reason for that impossibility.

Cheers,
Gabriel

It doesnt seem to follow normal pattern of callback ( error, result)?

Add support for basic recover http://www.rabbitmq.com/amqp-0-9-1-quickref.html#basic.recover

"Redeliver unacknowledged messages.

This method asks the server to redeliver all unacknowledged messages on a specified channel. Zero or more messages may be redelivered. "

Is there any way to find out how many messages there are in a queue?

Hi, I am using RabbitMQ for my application.
For testing purpose I have put the code for publishing messages in forever while loop. But its not working.
While I am sending one message alone, its working well.

My code for 1st problem is:

var sys = require('sys');
var amqp = require('amqp');

var connection = amqp.createConnection({ host: 'ip_address',vhost:'/' });

connection.addListener('close',function(){

if(e){
    throw e;
}else{
    sys.put("Connection Closed..");
}

});

// Wait for connection to become established.
connection.on('ready', function () {

var q = connection.queue('anand_queue',{durable: true,autoDelete:false});
q.bind("*");

while(true){        
            //if i comment while loop then it works well
    connection.publish('my_queue',"hello",{contentType: 'text/plain'});
}//end of while         

});

I have also observe that amqp uses buffer to store messages and then send messages in queue.
How can i overcome with this problems?

From what i can gather inspecting the source code this is not yet implemented? Is there a pragmatic reason for this? If not I'll see what I can wipe up this weekend now I understand a little more about this library

Hi !

I am actually able to send a "Hello World" via AMQP publishing, and to the value by subscribing.

I would like, instead of sending a simple "Hello World", to send a complex object like a JSON object.
I am not sure if what I say makes sense, so I illustrate it with an example :

Here is a class :

var MyClass;
MyClass = (function() {
function MyClass(myText) {
if (myText == null) {
myText = "test";
}
this.myText = myText;
}
MyClass.prototype.display = function() {
return "Method display works : " + this.myText;
};
return MyClass;
})();

I will do this to create the object, then I send it with node-amqp :
var test = new MyClass("Hello World !!!");

And after receiving the object by subrscribing to the queue, I am able to get json.myText, but not able to call the method djson.display().

For example :

q.subscribe(function (json, headers, deliveryInfo) {
recvCount++;
assert.equal("node-json-fanout", deliveryInfo.exchange);
assert.equal("node-json-queue", deliveryInfo.queue);
assert.equal(false, deliveryInfo.redelivered);

  // Receiving a message
  switch (deliveryInfo.routingKey) {
    case 'message.json1':
      console.log("message 1 : " + json.myText + " And here is the method call: " + json.display());
      break;

    default:
      throw new Error('unexpected routing key: ' + deliveryInfo.routingKey);
  }
})

I have the error : TypeError: Object # has no method 'display'

When I did some messaging with Ruby + the RabbitMQ gem (an AMQP implementation), I was able to send objects (with attributes and methods) and use it after receiving by "marshalling" the object before sending, and unmarshalling the object at reception.

I need a method that equals the function of "Marshalling" / "Unmarshalling" or something which will permit me to send/reveive objects issued from a "new" and to be able to use its attributes (here I am already able to do it), but ALSO its METHODS ! How can I do it ?

Thanks for your help !

I'd like to use {mandatory: true} when publishing a message so that I can prevent my messages from being dropped. However, I'm unsure how this is supposed to be done. In the example below, I catch an event ('basicReturn') when a message isn't going to be delivered anywhere, but I also get this error:

Warning: Uncaught basicReturn: {"replyCode":312,"replyText":"NO_ROUTE","exchange":"","routingKey":"example3"}

This leads me to believe that I'm using the library incorrectly. What is the proper way to do this?

Example:

var amqp = require('amqp');

var connOpts = { ... };

var connection = amqp.createConnection(connOpts);

connection.on('ready', function () { 
  var q = connection.queue('example2', function (queue) { 
    var exchange = connection.exchange('', {});
    exchange.on('open', function(){
      var publishReturn = exchange.publish('example3', {txt: 'hello, world'}, {mandatory: true});
      exchange.on('basicReturn', function(x) {
        console.log('handling basic return');
        console.log(x);
      });
    });
  });
});

Thanks

I'm trying to set up a round-robin style worker queue and am not seeing any direct messages arrive at any subscribers. In the spirit of creating a simple test case, I modified the test-simple.js sample to create a new direct exchange: https://gist.github.com/ab3e637c0717a7a8e096. I'm not seeing any messages show up.

Fanout messages seem to propagate just fine.

Is there something missing here?

Thanks,

Matt

Hello,

I tried to use the subscribe() method and when I received the message in a variable called m, I tried to use the methods m.addListener() and m.acknowledge()

But I had an error saying that these 2 methods did not exist. The only way I found to use these methods was to use them into "subscribeRaw()" and not "subscribe()".

So I needed to make the object being a string then to parse it into a json object.

We should be able to acknowledge() or use the other methods available for subscribeRaw() into the subscribe() method to be able to acknowledge simple json/application object type.

because subscribeRaw() sends messages in some type like octet/stream which I didn't need but I was obliged to use it in order to access to the needed method "m.acknowledge"

When I start at first, a server in listening for messages, and THEN, a client publishing 4 messages :
I see 4 messages received at server side

BUT there is a problem, when I start a client publishing 4 messages (while the subscriber is off, but the daemon RabbitMQ is started of course), and THEN I start the server in order to subrscribe to the queue and to receive these 4 same messages, I receive only 3 messages, and every other messages are received normally.

The fact is that the FIRST message is never seen at the server side if I publish before subscribing.
How can I resolve this problem ?

In AMQP, the exchange know as the "default exchange" is that referenced by not supplying an exchange name (usually interpreted in client libraries as an empty string). Its purpose is to allow messages to be published directly to queues.

node-amqp, from its early days, has used the exchange "amq.topic" as the target when an exchange name is not supplied to procedures.

"amq.topic" is something of an odd choice. It is not guaranteed to exist -- the spec asks that it be initially present in each vhost (and so it is in rabbitmq), but it is otherwise not special, and may be deleted for example.

Ideally, node-amqp would follow the semantics as indicated by the specification, and a procedure that doesn't use an exchange name would publish to the actual default exchange. I'm thinking of Connection.publish specifically. However, it may be that applications rely on the current behaviour.

The choices are at this point:

1. Correct the behaviour of Connection.publish
2. Keep the current behaviour of Connection.publish, and
   a. Supply queue.publish, for publishing directly to a queue
   b. Supply Connection.publishToQueue
   c. Require people to use Connection.exchange('').publish(queueName, ...)

I've implemented 2a, but it's unsatisfactory as it requires a channel creation to get the queue, which is not actually needed for the publish. Of the 2s, 2b is probably best. But 1 is better still from my point of view.

In any case, the README ought to be fixed up -- when my changeset doing 1 above was merged, the behaviour was reverted, but not the README apparently.

I'm happy to do the work for this, but I need to know which option is going to be acceptable.

We have severe performance problems with node-amqp when under load in production. To reproduce I created this little publisher program:

var amqp = require('amqp');

var conn = amqp.createConnection({url: "amqp://guest:guest@localhost:5672"});
conn.on('ready', function(){

    for(var i = 0; i < 50000; i++){
        conn.publish('labs', {my: "paylaod" + i});
    }

    console.log('published ' + i + ' messages');
});

On the other end of RabbitMQ this little program reads messages as they are published and display some timing statistics:

var amqp = require('amqp');

var conn = amqp.createConnection({url: "amqp://guest:guest@localhost:5672"});

conn.on('ready', function(){
    var n = 0;
    conn.queue('labs', function(queue){
        var prev = new Date().getTime();
        queue.subscribe(function (message, headers, deliveryInfo) {
            n++;
            if(n % 1000 === 0){
                var next = new Date().getTime();
                console.log('read ' + n + ' messages in ' + (next - prev) + " ms");
                prev = next;
            }
        });
    });
});

As you can see the test run results show that performance is significantly deteriorated as more and more messages are published:

read 1000 messages in 352 ms
read 2000 messages in 395 ms
read 3000 messages in 418 ms
read 4000 messages in 500 ms
read 5000 messages in 459 ms
read 6000 messages in 479 ms
read 7000 messages in 469 ms
...
read 46000 messages in 2778 ms
read 47000 messages in 2767 ms
read 48000 messages in 2818 ms
read 49000 messages in 2814 ms
read 50000 messages in 2847 ms

I re-wrote the publisher program in Python using pika, for comparison:

import pika

def main():
    connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
    channel = connection.channel()

    for i in range(50000):
        channel.basic_publish(
            exchange='',
            routing_key='labs',
            body='{"my": "payload"}')

    print " [x] Sent " + str(i) + " messages"

    connection.close()


if __name__ == '__main__':
    main()

As you can see the test run with pika shows much better performance that stays constant for the whole run:

read 1000 messages in 232 ms
read 2000 messages in 235 ms
read 3000 messages in 221 ms
read 4000 messages in 223 ms
read 5000 messages in 227 ms
read 6000 messages in 224 ms
read 7000 messages in 225 ms
...
read 46000 messages in 237 ms
read 47000 messages in 218 ms
read 48000 messages in 247 ms
read 49000 messages in 225 ms
read 50000 messages in 229 ms

Would you be able to look into why the difference in performance between two technologies is so significant and if this can be addressed? Thanks!

I am opening my queue like this:
var q = connection.queue('MyQueue, {passive: true},function(queue) { console.log("Queue " + queue.name + " is open");});

Whether I set passive to true or false I get the error:

Error: NOT_FOUND - no queue 'MyQueue' in vhost '/'

It is my understanding from the readme that if I set the passive to true the queue will be created if it does not exist. But this does not seem to be the case.

Hi,

I made a class named Queue.js that is using node-amqp and I do a "require" of this class into a client.js and a server.js

The class Queue.js contains a constructor and 2 methods :

• addTaskToQueue(hereIsTheObjectToSend)
• subscribeToQueue() // this method returns an object

In this way I am able to use node-amqp messaging more easily.

here is client.js :

var Queue = require('./Queue.js'); // the class that I use to manage easily message sending/received
var MyClass = require('./MyClass.js'); // a simple class that has only a constructor that has the attribute MyClass::message
var myObject = new MyClass("Hi, here is my message"); // Now I have myObject.message containing some text

var queue = new Queue("localhost", "salut"); // creation of the queue on localhost, to queue named "salut"
queue.addTaskToQueue(myObject); // Here I send 4 times the same messages
queue.addTaskToQueue(myObject);
queue.addTaskToQueue(myObject);
queue.addTaskToQueue(myObject);

// this timeout waits 3 seconds, then send another message
setTimeout(function () {
// wait 3 sec to send another message
queue.addTaskToQueue(myObject); // this message should be sent, but it never displays when I execute the program
console.log("It should have 5 messages sent now"); // this console.log is correctly displayed after 3 seconds
}, 3000);

In the linux terminal, I start the server in listening, then the client, so the client send this

$ node client.js
publishing the json message...
publishing the json message...
publishing the json message...
publishing the json message...
#3 seconds after it adds the line :

It should have 5 messages sent now

And at the linux terminal using server.js :

$ node server.js
{ message: 'Hi, here is my message' }
{ message: 'Hi, here is my message' }
{ message: 'Hi, here is my message' }
{ message: 'Hi, here is my message' }

but I don't see the 5th message. The message is not send while it is in a setTimeout function. But I need to use setTimeout because I need to implement the possibility when a message is not received to the server (so, if the server doesn't ACKnowledge the message), the client should wait 5 minutes to send the message again.

How should I do ?

Also added the ability to close a connection via

Connection.prototype.closeConnection = function () {
//
// 0 is the control channel
//
this._sendMethod(0, methods.connectionClose, {'replyText': 'Goodbye from node',
'replyCode': 200,
'classId': 0,
'methodId': 0});
//this.end();
};

then on _onMethod

case methods.connectionCloseOk:
this.end();
this._onMethod(0, methods.connectionClose, args);
break;

I end the connection. I don't know how to do the social commit or things that make github great. I can push these to you if you like.

I noticed that in the comments, you have experation,

./amqp/amqp.js:// - experation
./amqp/amqp.js:// - experation
./amqp/amqp.js:// - experation
./amqp/index.js:// - experation
./amqp/index.js:// - experation
./amqp/index.js:// - experation

but in the AMQP XML definitions it specifically ONLY has.

If you are going to list possible options of arguments in the comments for user to follow, could you please correct it if its wrong. Or do some magic and make both work ;-)

Cheers

Raul

Error -

=ERROR REPORT==== 3-Jun-2011::11:07:58 ===
exception on TCP connection <0.1026.0> from 127.0.0.1:34321
{bad_header,<<65,77,81,80,0,0,9,1>>}

Connection code -

var amqp_conn = amqp.createConnection({ host: 'localhost', login: 'guest', password: 'guest', vhost : '/' });

Great module by the way. Keep up the great work.

The example could never work now.
q.bind and q.subscribe should be called when the queue is ready - on callback in connection.queue as it does in test harness test file - test-queue-creation.js
Also it says that amq.topic default exchange is used, but it's defaultExchangeName is set to '' now.

While writing a new example for rabbit.js, I ran into this problem: there's no way to unsubscribe from a queue, meaning that messages will keep being delivered even if you have removed the listener.

In general this is OK if not ideal -- the messages just get dropped on the floor if there's no listener. The case in which it matters is when you have more than one subscriber. RabbitMQ (and all those other AMQP brokers that there are) will deliver messages round-robin to the subscribers. If you stop handling some messages they'll just get lost -- what you really want is for those messages to go to one of the other subscribers.

In test.js the line

q.bind(exchange, "*").addCallback(function () {

causes

TypeError: Cannot call method 'addCallback' of undefined

** This behavior is on linux 32bit with node v0.5.0-pre

See: https://github.com/postwait/node-amqp/blob/master/amqp.js#L907
You should add var before urlo otherwise it is considered as a global variable.

Perhaps a silly question but: when I get a message back from a subscribed queue it looks like:

{ data: <Buffer 54 65 73 74 20 54 69 63 6b 6c 65>,
contentType: 'text/plain' }

printing just message.data is:
<Buffer 54 65 73 74 20 54 69 63 6b 6c 65>

How do I get that data back as actual plain text?

Hi,

I can install amqp normally:

$ sudo npm install amqp -g
Password:
npm http GET https://registry.npmjs.org/amqp
npm http 304 https://registry.npmjs.org/amqp
[email protected] /usr/local/lib/node_modules/amqp

But it doesn't work when i try to start with node.js

node.js:201
        throw e; // process.nextTick error, or 'error' event on first tick
              ^
Error: Cannot find module 'amqp'
    at Function._resolveFilename (module.js:332:11)

Any ideas of what i'm doing wrong?

I'm running node.js v0.6.12 on Lion.

Thanks.

I am using the module node-amqp by postwait : https://github.com/postwait/node-amqp

I am able to publish/subscribe to a queue some messages, but I would like to acknowledge the messages manually.

For example, I want the message to be read, and not acknowledged, then to execute some calculation on this message, and THEN send a q.shift() to acknowledge the message and go through the second message.

I want the acknowledges to be manually used.

Actually I have a function which permits to subscribe with the flag {ack: false} then I have a function to manually make a q.shift() (as said in the doc).

But when I publish 2 messages, and then I read 2 messages, without acknowledging, I see the 2 messages. But I would like the subrscribe to repeat the same message that was received at first, until I didn't acknowledge it.

How can I use the methods ?

I need to collect messages to be processed in batch on remote service, i also want to be sure that messages safely stored in durable queue until have not been processed by service.
To implement this approach i use durable queue with prefetchsize = batchsize and manual acknowledge.

  var batch = new Array();
   var q = connection.queue('Q', {durable : true});

   // HERE I NEED TO SAY    q.basicQos(5);

    q.on('queueDeclareOk', function (args) {
        q.bind(e, "key");
        q.subscribeRaw({ack:true}, function(message) {
            batch.push(message);
            if(batch.length == BATCH_SIZE){
                self.batch.forEach(function(m){
                    m.acknowledge();
                });
                self.batch.length = 0;
            }
        });
    });

I've made temporary patch in local copy:

Queue.prototype.basicQos = function(prefetchCount){
this.connection._sendMethod(this.channel, methods.basicQos,
{ reserved1: 0
, prefetchSize: 0
, prefetchCount: prefetchCount
, global: false
});
};

Hi,

I'm using ack: true and prefetchCount: 0 in my queue. I know that i have to use queue.shift() to ack my messages but from i've read this will ack the last message.

Is there a way to ack a specific message? Example: using message variable in the callback of queue.subscribe.

Currently when binding to a queue you MUST match the queue parameters exactly or it will not work at all. For example, if I have queue "a" that is durable and not auto-delete, the following code will never work:

var q = conn.queue('a');

q.subscribe(function(msg){
  console.log(msg);
});

But if I match what it really is:

var q = conn.queue('a', {durable:true, autoDelete:false});

q.subscribe(function(msg){
  console.log(msg);
});

It works.

I'd like to be able to just listen on a queue without knowing the explicit details of it. Or, if I get the options wrong it'd be nice to make a lot of noise rather than silently failing. :)

Thanks,
James

As seen here: https://github.com/postwait/node-amqp/blob/v0.1.0/amqp.js#L1703

The error emitting code is commented out, the code itself is correct - although it should probably throw an exception rather than printing to stdout.

It would also be nice to document the close/error events on the channel objects, as this took me a long time to track down and involved dumping packets and reading the binary protocol by hand :)

If i setup a connection and just publish a lot of messages. All works fine -> messages get published to the queue.

But if i look at memory usage it goes up and stays at the high level. I didn't found out where the problem is.

Sample Code i used:

var amqp = require('amqp')
  , connection = amqp.createConnection({url: "amqp://guest:guest@localhost:5672"});

connection.on('ready', function () {

    for (i = 1; i <= 300000; i++) {
        connection.publish('sample', {msg: i + ' hello world'});
    }

});

This might be related to receiving a large message, it doesn't seem to happen all the time. Looks to be related to some code that was recently committed.

buffer.js:494
    throw new Error('sourceEnd out of bounds');
          ^ 
Error: sourceEnd out of bounds
    at Buffer.copy (buffer.js:494:11)
    at frame (/smartdc/node_modules/amqp/amqp.js:169:10)
    at header (/smartdc/node_modules/amqp/amqp.js:159:14)
    at frameEnd (/smartdc/node_modules/amqp/amqp.js:204:16)
    at frame (/smartdc/node_modules/amqp/amqp.js:171:14)
    at header (/smartdc/node_modules/amqp/amqp.js:159:14)
    at frameEnd (/smartdc/node_modules/amqp/amqp.js:204:16)
    at frame (/smartdc/node_modules/amqp/amqp.js:171:14)
    at AMQPParser.header [as parse] (/smartdc/node_modules/amqp/amqp.js:159:14)
    at AMQPParser.execute (/smartdc/node_modules/amqp/amqp.js:230:21)

I'm using {passive:false} to test if a queue exists. As expected, if the queue doesn't exist, I get an exception. However, it's not "catchable". Shouldn't this error be caught on the connection object if connection.on('error. . .is setup?

var amqp = require('amqp');
var connection = null;

var get_connection = function(cb) {
if (connection === null) {
connection = amqp.createConnection({host: "localhost"});
connection.on('ready', function() {
console.log('ready');
connection.exchange("mog");
cb(connection);
});
connection.on('error', function(e) {
console.log("error: " + e);
log.error("---->AMQP connection closed");
connection = null;
});
connection.on('end', function() {
connection = null;
});
connection.on('close', function(){
console.log("closed");
});
}
else {
cb(connection);
}
};

get_connection(function(conn){
conn.queue("foo2", {'passive':true},function(q){
console.log(q);
});
});

process.on("uncaughtException", function(e){
// caught here
console.log(e);
});

Error: NOT_FOUND - no queue 'foo2' in vhost '/'
at Queue._onMethod (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:1703:15)
at Queue._onChannelMethod (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:1348:14)
at Connection._onMethod (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:917:28)
at AMQPParser.onMethod (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:792:12)
at AMQPParser._parseMethodFrame (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:441:10)
at frameEnd (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:186:16)
at frame (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:171:14)
at AMQPParser.header as parse
at AMQPParser.execute (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:230:21)
at Connection. (/Users/rich/dev/foo/foojs/node_modules/amqp/amqp.js:832:12)

When running npm install amqp (using node 0.6.0)

I get installed this;

{ "name" : "amqp", "version" : "0.0.2" }

I guess you have to update your package info to include node engine 0.6 , and to future proof it, add >0.4

Sorry if this is more a question than a bug.

I'm publishing to a topic exchange from a 'fire and forget' type script, and cant find a way to cleanup when the publish has occurred. Making do with a setTimeout block, but that feels hacky (and error prone).

A lot of the API methods seem to take a callback that fires after the operation, but exchange.publish doesn't seem to.
What's the best way to know when the publish method has completed? Thanks.

When I publish a message using Exchange.publish(), it returns a promise. That promise never has success emitted, even if the message is delivered successfully to the server. In fact, it is never called even when my consumer process on the other end logs that the message was delivered.

To recreate:

// assuming you have a connection and exchange is a valid exchange object
var promise = exchange.publish('everyone', 'hello world');

promise.on('success', function(){
console.log('you will never see this');
});

promise.addCallback(function(){
console.log('...or this');
});

The Protobuf C++ module for node generates SlowBuffers, rather than Buffers (I believe that most modules with a native component will do the same ... Buffers appear to be more difficult to manipulate from C++). These can't be passed along to AMQP, because of the check on amqp.js line 1135 for body instanceof Buffer. That check should probably be Buffer.isBuffer(body) instead, otherwise the check fails and AMQP regards the SlowBuffer as JSON and tries to encode it. There are a few more cases in the source where instanceof Buffer is used, and most of them should probably be changed.

This is a problem resulting from caching queues and hiding channels: message prefetch is defined per channel, but a queue (= one channel) may have more than one consumer. If queue.subscribe and the option autoAck: false are used, it sets the prefetch to 1, meaning that another message won't be sent until the previous has been acknowledged.

If there's more than one consumer, then it's easy for one of them to unjustly starve the others by not acknowledging a message. Say, for example, each consumer is piping messages through a stream, and only acknowledging them once the message has successfully written; if the stream is paused, the acknowledgment won't be made, and no other consumer will receive a message either, because they are all sharing the channel and thus the prefetch.

One possible solution to this is to unhide channels, so to allow a channel per consumer. The API as is can be kept as a convenience, and channel exposed for when more fine-grained control is needed. Thoughts? (or would you prefer to wait for a pull request ..)

When calling "connection.exchange(...)" or "connection.queue(...)" the callback isn't being executed. I can profile the amqp.js file and see it in the Exchange and Queue objects, but it's not being executed. It's only invoked if the Exchange or Queue names already exist.

amqp v0.1
node v0.4.11
rabbitmq v2.6.1

When creating a new Queue, it is never registered in RabbitMQ. I have the web mgmt console running and I can see amqp create the Exchange properly, but the Queue does't get created after the Exchange. When profiling the library, I can see that the calls to create a Queue and Exchange are nearly identity, so I'm not sure why one would be created but not the other. I do see that the code continues through fine and doesn't skip the Queue creation (no exceptions that I can see). I can alternatively create the queue via the web mgmt console, without problem. I have also tried using rabbit.js (https://github.com/squaremo/rabbit.js) with [email protected], and it DID seem to make the queue. I thought that maybe it wouldn't be created until a message came through, so I tried from a client sending to the Exchange, but again, no Queue was created.

Here's an example:

var amqp=require('amqp');
var connection=amqp.createConnection({host:'localhost'});
connection.on('ready', function(){
    var exchange = connection.exchange('echo-exchange'); // will create the exchange
    var queue = connection.queue('echo-queue'); // will NOT create the queue
    queue.bind('echo-exchange', 'foo.*');
    queue.subscribe( {ack:true}, function(message){
        console.log(message); // never called because the queue is never created
        queue.shift();
    });

});

I'm getting occasional crashes inside amqp.js in the following place (around line 832):

  self.addListener('data', function (data) {
    parser.execute(data);
  });

self.addListener('end', function () {
    self.end();
    // in order to allow reconnects, have to clear the
    // state.
    parser = null;
  });

This is my stack trace:

/usr/local/marquee-web/node_modules/amqp/amqp.js:851
    parser.execute(data);
           ^
TypeError: Cannot call method 'execute' of null
    at Connection.<anonymous> (/usr/local/marquee-web/node_modules/amqp/amqp.js:851:12)
    at Connection.emit (events.js:67:17)
    at TCP.onread (net.js:347:14)

Just before that I'm also getting an 'error' event from AMQP connection object. As you can see from the code above the parser is indeed set to null when connection ends. Is this a race condition of some sort?

addListener to 'end' but it doesn't work when connection is shutdown(maybe network problem or something)
I'm trying to use node.js and amqp on webOS, network switching frequently will be a big problem

the code at https://github.com/xaviershay/node-amqp seems support 0.2.x node.js, why this one must be node.js 0.4 or later?