ExchangeDescriptor¶

ExchangeDescriptor describes a RabbitMQ exchange.

It derives from ServiceDescriptor, so it inherits the naming model based on Prefix, Name and FullName.

Inheritance¶

classDiagram
    direction TB

    class ServiceDescriptor {
        +string Prefix
        +string Name
        +string FullName
    }

    class ExchangeDescriptor {
        +ExchangeTypes Type
        +bool Durable
        +bool AutoDelete
        +IDictionary~string, object~ Arguments
    }

    ServiceDescriptor <|-- ExchangeDescriptor

Purpose¶

Use ExchangeDescriptor when a client needs to describe an exchange that participates in a subscriber binding or topology definition.

For publisher topologies, ExchangeBoundDescriptor extends this model with binding composition.

Naming¶

ExchangeDescriptor uses the default prefix:

esb/exchange

Example:

new ExchangeDescriptor
{
    Name = "orders"
};

The physical RabbitMQ exchange name is:

esb/exchange/orders

The provider uses FullName when declaring the exchange.

Properties¶

Property	Description
`Name`	Logical exchange name.
`Prefix`	Exchange namespace prefix.
`FullName`	Physical RabbitMQ exchange name.
`Type`	RabbitMQ exchange type.
`Durable`	Indicates whether the exchange survives broker restarts.
`AutoDelete`	Indicates whether the exchange can be automatically deleted.
`Arguments`	RabbitMQ exchange declaration arguments.

Exchange Type¶

Type defines how RabbitMQ routes messages through the exchange.

Common values are:

direct
topic
fanout
headers

Example:

var exchange = new ExchangeDescriptor
{
    Name = "orders",
    Type = ExchangeTypes.Topic,
    Durable = true,
    AutoDelete = false
};

Runtime Behavior¶

graph LR

    ExchangeDescriptor --> FullName

    FullName --> RabbitMQExchange["RabbitMQ Exchange"]

The descriptor does not route messages directly.

It describes the exchange that the provider should declare and use.

When To Use¶

Use ExchangeDescriptor when configuring subscriber-side exchange binding.

Use ExchangeBoundDescriptor when the exchange also needs to describe queues or child exchanges in a publisher topology.

ServiceDescriptor
ExchangeBoundDescriptor
SubscriberBoundDescriptor
BinderDescriptor