Virtual Hosts (vhosts)

Overview

A virtual host (vhost) in RabbitMQ is a logical partition of the broker — it has its own exchanges, queues, bindings, user permissions, and policies. Resources in one vhost are invisible to connections in another, just like separate databases in a relational DB server. The default vhost is "/". Vhosts are ideal for multi-tenant deployments, environment separation (dev/staging on one broker), or team isolation without spinning up separate brokers. Each user is granted access to specific vhosts with configure, write, and read permission regexes.

Creating and Connecting to Vhosts

# Create a vhost
rabbitmqctl add_vhost orders

# Grant user "order-svc" full access to /orders vhost
rabbitmqctl set_permissions -p orders order-svc ".*" ".*" ".*"

# Connection URI with vhost
# amqp://user:password@host:5672/orders

# Spring Boot application.yml
spring:
  rabbitmq:
    host: rabbitmq.internal
    port: 5672
    username: order-svc
    password: secret
    virtual-host: orders

Vhost Isolation in Practice

# Development environment: vhost = /dev
rabbitmqctl add_vhost /dev
rabbitmqctl set_permissions -p /dev dev-user ".*" ".*" ".*"

# Staging environment: vhost = /staging
rabbitmqctl add_vhost /staging
rabbitmqctl set_permissions -p /staging staging-user ".*" ".*" ".*"

# Both vhosts can have an exchange named "orders" — fully isolated
# /dev/orders exchange and /staging/orders exchange never interact

# List vhosts
rabbitmqctl list_vhosts

Vhost Policies and Limits

# Apply a policy to all queues in /orders vhost (max 100k messages)
rabbitmqctl set_policy -p orders MaxLen ".*"   '{"max-length": 100000, "overflow": "reject-publish"}'   --apply-to queues

# Limit connections per vhost (management HTTP API)
PUT /api/vhost-limits/orders
{ "max-connections": 50, "max-queues": 200 }

# List policies for a vhost
rabbitmqctl list_policies -p orders

Key Points to Remember

• 1Vhosts provide complete isolation: exchanges, queues, and bindings are scoped to a single vhost
• 2Default vhost is "/"; connect with virtual-host: / in Spring or amqp://host/vhost in URIs
• 3User permissions are per-vhost with configure (declare), write (publish), read (consume) regexes
• 4Use vhosts for environment separation (dev/staging) or team isolation on a shared broker
• 5Policies (TTL, max-length, HA) are applied at vhost level and affect only resources within it
• 6Vhost limits (max-connections, max-queues) prevent one tenant from monopolising broker resources