Error event is emitted due to normal connection close from RabbitMQ side

[xaka]

Hi there,

I was verifying how service behaves when RabbitMQ gets restarted, etc. and I've got the following:

Error: Connection closed: 320 (CONNECTION-FORCED) with message "CONNECTION_FORCED - broker forced connection closure with reason 'shutdown'"
    at Object.accept (../node_modules/amqplib/lib/connection.js:89:32)
    at Connection.mainAccept [as accept] (../node_modules/amqplib/lib/connection.js:62:33)
    at Socket.go (../node_modules/amqplib/lib/connection.js:459:48)
    at Socket.emit (events.js:92:17)
    at emitReadable_ (_stream_readable.js:426:10)
    at emitReadable (_stream_readable.js:422:5)
    at readableAddChunk (_stream_readable.js:165:9)
    at Socket.Readable.push (_stream_readable.js:127:10)
    at TCP.onread (net.js:528:21)

It was absolutely usual RabbitMQ restart procedure and service crashed because it was expecting to get close event, but not error.

In my opinion there should be no error event when library gets 320 code from RabbitMQ. Even though it's called CONNECTION-FORCED, there is nothing wrong happened.

[squaremo]

I see what you mean. Would your code be happy if it got a 'close' event instead? (You imply this, just making sure)

[xaka]

It gets close event, but too late, when everything is about to crash due to unhandled error :) The point is 320 code from RabbitMQ shouldn't be treated as an error, but as usual connection close flow IMHO.

[vicneanschi]

Hi squaremo,

did you have a chance to fix that?

[squaremo]

I (think I) have fixed this in master, if you would like to give it a try @vicneanschi @xaka

[jgato]

Hi there,

I would like to detect correctly this connection-forced (close connection) to enable a manual reconnection process. But I have two issues:

• If I use the .on('error'...) the received object is an error object, but not correctly composed. I mean, only the message attribute is filled, so, if I have to distinguish different errors this will be a problem:

Somewhere, this error object is not been created correctly.

• If I use the .on('close', function(msg)... ) but the invoked callback does not receive any parameter.

What should be the best option to detect this closing connection with the server?

[jgato]

I think it is related to: #149

[squaremo]

@jgato Is this still a source of problems? My test program

var amqp = require('amqplib/callback_api');

amqp.connect(onOpen);

function onOpen(err, conn) {
  if (err !== null) {
    return console.error(err);
  }
  conn.on('error', function(err) {
    console.log(err);
  });
  conn.connection.stream.write(new Buffer('garbage'));
}

prints out a "proper" error so far as I can tell. (By the way I've added a bit to put the replyCode on the error, and to give the close event the message, as you suggested above)

[mike-lang]

Is this now expected behavior? Your API documentation seems to clearly state:

#on('error', function (err) {...})

Emitted if the connection closes for any reason other than #close being called; such reasons include:

a protocol transgression the server detected (likely a bug in this library)
a server error
a network error
the server thinks the client is dead due to a missed heartbeat
a human closed the connection with an admin tool

I was going to attach a handler to the error event in my client to attempt to re-establish its connection a fixed number of times upon closure caused by error or by action on the server. Using node 4.1.2 with amqp.node 0.4.0, talking to rabbitMQ 3.5.6, when I close the connection through the server side admin tool, on the client end the close event fires, but the error event does not.

[VMBindraban]

It seems that this is still an issue on 0.5.1.

[cressie176]

When I run the following script then gracefully stop the broker I get a channel close event followed by a connection close event. The connection close event still provides an error object though.

const amqp = require('amqplib');

(async () => {
  const connection = await amqp.connect();
  connection.on('error', (err) => {
    console.log('Connection Error', err);
  })
  connection.on('close', (err) => {
    console.log('Connection Closed', err);
  })

  const channel = await connection.createChannel();
  channel.consume('test', (message) => {
    console.log({ message });
  })

  channel.on('error', (err) => {
    console.log('Channel Error', err);
  })
  channel.on('close', (err) => {
    console.log('Channel Closed', err);
  })
})();

Channel Closed undefined
Connection Closed Error: Connection closed: 320 (CONNECTION-FORCED) with message "CONNECTION_FORCED - broker forced connection closure with reason 'shutdown'"
at Object.accept (/Users/steve/Development/cressie176/amqplib-110/node_modules/amqplib/lib/connection.js:91:15)
at Connection.mainAccept (/Users/steve/Development/cressie176/amqplib-110/node_modules/amqplib/lib/connection.js:64:33)
at Socket.go (/Users/steve/Development/cressie176/amqplib-110/node_modules/amqplib/lib/connection.js:478:48)
at Socket.emit (events.js:400:28)
at emitReadable_ (internal/streams/readable.js:555:12)
at processTicksAndRejections (internal/process/task_queues.js:81:21) {
code: 320
}