Bug or Feature? amqp: SendToChannel without Listener => Error 404 - no exchange

me23 commented 2 years ago

Prerequisites

Please answer the following questions for yourself before submitting an issue.

[x ] I am runno exchangening the latest version
[ x] I checked the documentation and found no answer
[ x] I checked to make sure that this issue has not already been filed
[ x] I'm reporting the issue to the correct repository

Current Behavior

Starting with an fresh instance of rabbitmq and trigger sendToChannel from moleculer i got follow Error: [2022-05-10T07:30:40.939Z] ERROR my-client/CHANNELS: AMQP channel error Error: Channel closed by server: 404 (NOT-FOUND) with message "NOT_FOUND - no exchange 'something.done' in vhost '/'"

and the client exits with unhandled Promise-rejection.

As soon if i start a listener for this channel (somthing.done) once, even if i stop the listener again, then it works like expected.

Expected Behavior

I don't know if its an bug or a feature, but i expected the channel to be created either if the first listener register or if the first producer send some messages in.

My idea was to send some events with a ttl-value, so if nobody cares about it, it will be deleted. As soon as one consumer came up, he can use the stored events. no exchange

Failure Information

[2022-05-10T07:30:40.939Z] ERROR my-client/CHANNELS: AMQP channel error Error: Channel closed by server: 404 (NOT-FOUND) with message "NOT_FOUND - no exchange 'something.done' in vhost '/'"
at Channel.C.accept (/home/me/public_html/moleculer-channel-test/node_modules/amqplib/lib/channel.js:422:17)
    at Connection.mainAccept [as accept] (/home/me/public_html/moleculer-channel-test/node_modules/amqplib/lib/connection.js:64:33)
    at Socket.go (/home/me/public_html/moleculer-channel-test/node_modules/amqplib/lib/connection.js:478:48)
    at Socket.emit (node:events:527:28)
    at Socket.emit (node:domain:475:12)
    at emitReadable_ (node:internal/streams/readable:601:12)
    at processTicksAndRejections (node:internal/process/task_queues:82:21) {
  code: 404,
  classId: 60,
  methodId: 40
}
[2022-05-10T07:30:40.941Z] ERROR my-client/CHANNELS: AMQP channel closed.

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

start a fresh instance of rabbitmq
start producer that trigger sendToChannel("event.occured")
=> Error

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

Moleculer version: 0.14.21
NodeJS version: 17.9.0
Operating System: Ubuntu 22.04
"@moleculer/channels": "0.1.2",
"amqplib": "^0.8.0"

Failure Logs

icebob commented 2 years ago

Good question, but I don't think it's a bug. The publish doesn't create queues just puts the message to existing queues. Libraries of other adapters auto-create the queues if not exist. I will check what we can do, because in RabbitMQ there is several settings of the queues, so it means, you should define these settings in every publish (because you don't know whether the queue is exist or not). But I think it's not a good solution.

me23 commented 2 years ago

Maybe we could define a auto-create option and if it set, the service will check and create the necessary channels on startup?