FAQ — RabbitMQ

What is the difference between quorum queues and classic queues?

RabbitMQ offers two main types of queues:

• Quorum queues: based on the Raft consensus protocol, data is replicated across multiple cluster nodes. They guarantee message durability and high availability. Recommended for production.
• Classic queues: stored on a single node, faster for writes but without replication. If the node fails, messages are lost.

tip

With 3 or more replicas (replicas: 3), RabbitMQ uses quorum queues by default, ensuring message durability in case of a node failure.

What are virtual hosts (vhosts) used for?

Virtual hosts (vhosts) provide logical isolation within a single RabbitMQ cluster:

• Each vhost has its own exchanges, queues, and bindings
• Permissions are managed per vhost, allowing access control per application
• A user can have different roles depending on the vhost (admin on one, readonly on another)

Configuration example with multiple vhosts:

rabbitmq.yaml

vhosts:
  production:
    roles:
      admin: ["admin"]
      readonly: ["monitoring"]
  staging:
    roles:
      admin: ["admin", "dev"]

How do exchanges work in RabbitMQ?

An exchange receives messages from producers and routes them to queues according to binding rules:

Type	Behavior
direct	Routes the message to the queue whose routing key matches exactly
fanout	Broadcasts the message to all bound queues, without filtering
topic	Routes based on a routing key pattern (e.g., orders.*, logs.#)
headers	Routes based on message headers rather than the routing key

The producer publishes to an exchange, never directly to a queue.

What protocols are supported?

RabbitMQ on Hikube supports the following protocols:

Protocol	Port	Usage
AMQP	5672	Main messaging protocol
Management HTTP API	15672	Web interface and management API

What is the difference between resourcesPreset and resources?

The resourcesPreset field applies a predefined CPU/memory configuration, while resources allows you to specify explicit values. If resources is defined, resourcesPreset is ignored.

Preset	CPU	Memory
nano	100m	128Mi
micro	250m	256Mi
small	500m	512Mi
medium	500m	1Gi
large	1	2Gi
xlarge	2	4Gi
2xlarge	4	8Gi

Example with explicit resources:

rabbitmq.yaml

replicas: 3
resources:
  cpu: 2000m
  memory: 4Gi
size: 20Gi

How to access the management interface?

The RabbitMQ management interface is accessible on port 15672. Two options:

Option 1 — Port-forward (local access):

kubectl port-forward svc/<rabbitmq-name> 15672:15672

Then open http://localhost:15672 in your browser.

Option 2 — External access:

Enable external: true in your manifest to expose the service via a LoadBalancer:

rabbitmq.yaml

apiVersion: apps.cozystack.io/v1alpha1
kind: RabbitMQ
metadata:
  name: rabbitmq
spec:
  external: true
  replicas: 3
  resourcesPreset: small
  size: 10Gi

warning

External access exposes AMQP (5672) and Management (15672) ports on the Internet. Make sure to use strong passwords for all users.