TLDR: The relevant information can be found here: https://www.rabbitmq.com/access-control.html. However, since the rabbitmq documentation is very verbose, below I will describe what seems like the only solution to locking down access to resources. Summary Virtual hosts As Michael Dillon mentions, you should start by making everything happen inside vhosts (virtual hosts) and block the generic … Read more
RabbitMQ uses a custom DB to store the messages, the db is usually located here: /var/lib/rabbitmq/mnesia/rabbit@hostname/queues Starting form the version 3.5.5 RabbitMQ introduced the new New Credit Flow https://www.rabbitmq.com/blog/2015/10/06/new-credit-flow-settings-on-rabbitmq-3-5-5/ Let’s take a look at how RabbitMQ queues store messages. When a message enters the queue, the queue needs to determine if the message should be … Read more
Things that MT adds on top of just using RabbitMQ: Optimized, asynchronous multithreaded, concurrent consumers Message serialization, with support for interfaces, classes, and records, including guidance on versioning message contracts Automatic exchange bindings, publish conventions Saga state machines, including persistent state via Entity Framework Core, MongoDB, Redis, etc. Built-in metrics, Open Telemetry, Prometheus Message headers … Read more
An AMQP channel is closed on a channel error. Two common things that can cause a channel error: Trying to publish a message to an exchange that doesn’t exist Trying to publish a message with the immediate flag set that doesn’t have a queue with an active consumer set I would look into setting up … Read more
I would recommend amqp.node and bramqp over node-amqp. node-amqp has a lot of bugs and is poorly maintained, and it hides the “channel” concept which introduces a lot of problems for rabbitmq servers (because they are never closed).
One possible solution is to use non blocking connection and consume messages. import pika def callback(channel, method, properties, body): print(body) channel.basic_ack(delivery_tag=method.delivery_tag) def on_open(connection): connection.channel(on_open_callback=on_channel_open) def on_channel_open(channel): channel.basic_consume(queue=”queue1″, on_message_callback=callback) channel.basic_consume(queue=”queue2″, on_message_callback=callback) parameters = pika.URLParameters(‘amqp://guest:guest@localhost:5672/%2F’) connection = pika.SelectConnection(parameters=parameters, on_open_callback=on_open) try: connection.ioloop.start() except KeyboardInterrupt: connection.close() This will connect to multiple queues and will consume messages accordingly.
Short answer: To requeue specific message you can pick both basic.reject or basic.nack with multiple flag set to false. basic.consume calling may also results to messages redelivering if you are using message acknowledge and there are un-acknowledged message on consumer at specific time and consumer exit without ack-ing them. basic.recover will redeliver all un-acked messages … Read more
Rabbitmq uses the hostname as part of the folder name in the mnesia directory. Maybe add a –hostname some-rabbit to your docker run? I had the same issue and I found the answer here.
There does not seem to be a direct AMQP-way to manage the server but there is a way you can do it from Python. I would recommend using a subprocess module combined with the rabbitmqctl command to check the status of the queues. I am assuming that you are running this on Linux. From a … Read more
Usually I use very simple approach to memorize something. I will provide all details below, but here is a simple picture of BasicProperties field and values. I’ve also tried to properly highlight queue/server and application context. If you want me to enhance it a bit – just drop a small comment. What I really want … Read more