Chapter 7. Configuring the address space for message routing

AMQ Interconnect provides flexible application-layer addressing and delivery semantics. By configuring addresses, you can route messages in anycast (closest or balanced) or multicast patterns.

7.1. Routing messages between clients

By default, AMQ Interconnect distributes messages in a balanced anycast pattern (each message is delivered to a single consumer, and AMQ Interconnect attempts to balance the traffic load across the network). This means you only need to change the address configuration if you want to apply non-default semantics to an address or range of addresses.

Procedure

This procedure configures an address to use multicast distribution. The router network will distribute a copy of each message sent to this address to every consumer that is subscribed to the address.

  1. Start editing the Interconnect Custom Resource YAML file that describes the router deployment.

    $ oc edit -f router-mesh.yaml
  2. In the spec section, define the semantics to be applied to addresses.

    Sample router-mesh.yaml file

    apiVersion: interconnectedcloud.github.io/v1alpha1
    kind: Interconnect
    metadata:
      name: router-mesh
    spec:
      ...
      addresses:
      - pattern: */orders  1
        distribution: multicast

    1
    Messages sent to any address that ends with “orders” will be distributed in a multicast pattern.

    The Operator applies the changes to the router network and restarts each Pod.

  3. If you have additional router deployment Custom Resources that define routers in the router network, repeat this procedure for each CR.

    Each router in the router network must have the same address configuration.

Additional resources

7.2. Routing messages through brokers

If you need to store and forward messages, you can route them through a queue on a message broker. In this scenario, message producers send messages to a router, and the router sends the messages to a broker queue. When a consumer connects to the router to receive the messages, the router retrieves them from the broker queue.

You can route messages to brokers running in the same OpenShift cluster as the router network, or to brokers that are running outside of the cluster.

Prerequisites

  • You must have access to a message broker.

Procedure

  1. Start editing the Interconnect Custom Resource YAML file that describes the router deployment.

    $ oc edit -f router-mesh.yaml
  2. In the spec section, add a connector to connect to the broker, a waypoint address to point to the broker queue, and autolinks to create the links to the queue.

    Sample router-mesh.yaml file

    apiVersion: interconnectedcloud.github.io/v1alpha1
    kind: Interconnect
    metadata:
      name: router-mesh
    spec:
      ...
      addresses:
      - prefix: my-queue  1
        waypoint: true
      autoLinks:  2
      - address: my-queue
        direction: in
        connection: my-broker
      - address: my-queue
        direction: out
        connection: my-broker
      connectors:  3
      - name: my-broker
        host: broker
        port: 5672
        routeContainer: true

    1
    The address (or set of addresses) for which messages should be stored on a broker queue.
    2
    The autolink configuration. It defines the incoming and outgoing links and connection to be used to send and receive the messages on the broker.
    3
    The connection to be used to connect the routers to the message broker.

    The Operator applies the changes to the router network and restarts each Pod.

  3. Verify that the router has established the autolinks to the message broker.

    $ oc exec router-mesh-6d6dccb57f-x5cqf -it -- qdstat --autolinks
    AutoLinks
      addr      dir  phs  extAddr  link  status  lastErr
      ====================================================
      my-queue  in   1             26    active
      my-queue  out  0             27    active
  4. If you have additional router deployment Custom Resources that define routers in the router network, repeat this procedure for each CR.

    Each router in the router network must have the same address configuration.

Additional resources