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 protocol, data is replicated across several nodes of the cluster. They guarantee message durability and high availability. Recommended for production.
- Classic queues: stored on a single node, without replication between nodes. If that node fails, the messages are no longer available.
The queue type is chosen by the application when the queue is declared (argument x-queue-type: quorum).
To benefit from quorum queue replication, create the cluster with 3 (Max High Availability) or 5 (Ultra High Availability) replicas.
What are virtual hosts (vhosts) for?
Virtual hosts (vhosts) provide logical isolation within the same RabbitMQ cluster:
- Each vhost has its own exchanges, queues and bindings
- Rights are managed per vhost, which lets you control access per application
- A user can have different rights depending on the vhost (Administrator on one, Read-only on another)
Vhosts are created in the creation wizard (VHosts step) or later with Add a VHost on the cluster page. See Manage vhosts and users.
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 according to a routing key pattern (e.g. orders.*, logs.#) |
headers | Routes according to the message headers rather than the routing key |
The producer publishes to an exchange, never directly to a queue. Exchanges and bindings are declared by your applications.
Which port should I connect to?
AMQP clients connect on port 5672, at one of the addresses in the cluster's Connection section: the host in the Internal zone from the project's VMs and Kubernetes clusters, the address in the External zone from the Internet (when External Access is enabled).
Can the number of replicas or the preset be changed after creation?
No. The Number of replicas (and therefore the standalone or cluster mode) and the Preset are set at creation. The version (to a higher version), the disk size (upwards) and external access remain editable. See Change a cluster's configuration.
I have lost a user's password. How do I recover it?
The password is displayed only once and cannot be read again. Generate a new one with the user's Change Password action, then update your applications: the old password is revoked immediately.
What rights do "Administrator" and "Read-only" grant?
- Administrator: read, write and configure on the vhost (declare exchanges and queues, publish, consume).
- Read-only: read-only on the vhost.
A user without access to a vhost cannot connect to it.
How do I access the RabbitMQ management interface?
The Hikube console does not provide access to the RabbitMQ web management interface. With External Access, port 15672 of this interface is reachable at the cluster address, over unencrypted HTTP, but users created from the console do not have the RabbitMQ administration tag that it requires: they cannot log in to it. Vhosts and users are managed from the console; exchanges and queues, from your applications. For a specific need, contact support.
How is the cost of a cluster estimated?
The creation wizard displays a monthly and hourly Estimated Cost, calculated from the preset, the number of replicas, the disk size and external access. Actual billing is calculated per hour of use.