Chapter 2. Getting started

Procedure

1. Ensure your subscription has been activated and your system is registered.

   For more information about using the Customer Portal to activate your Red Hat subscription and register your system for packages, see Appendix B, Using your subscription.

2. Subscribe to the required repositories:

   Red Hat Enterprise Linux 6

   $ sudo subscription-manager repos --enable=amq-interconnect-1-for-rhel-6-server-rpms --enable=amq-clients-2-for-rhel-6-server-rpms

   Red Hat Enterprise Linux 7

   $ sudo subscription-manager repos --enable=amq-interconnect-1-for-rhel-7-server-rpms --enable=amq-clients-2-for-rhel-7-server-rpms

   Red Hat Enterprise Linux 8

   $ sudo subscription-manager repos --enable=amq-interconnect-1-for-rhel-8-x86_64-rpms --enable=amq-clients-2-for-rhel-8-x86_64-rpms

3. Use the yum or dnf command to install the qpid-dispatch-router, qpid-dispatch-tools, and qpid-dispatch-console packages and their dependencies:

   $ sudo yum install qpid-dispatch-router qpid-dispatch-tools qpid-dispatch-console

4. Use the which command to verify that the qdrouterd executable is present.

   $ which qdrouterd
   /usr/sbin/qdrouterd

   The qdrouterd executable should be located at /usr/sbin/qdrouterd.

Procedure

1. Open the following file: /etc/qpid-dispatch/qdrouterd.conf.

   When AMQ Interconnect is installed, qdrouterd.conf is installed in this directory. When the router is started, it runs with the settings defined in this file.

2. Review the default settings in qdrouterd.conf.

   Default Configuration File

   router {
       mode: standalone 

   1

   
       id: Router.A 

   2

   
   }
   
   listener { 

   3

   
       host: 0.0.0.0
       port: amqp
       authenticatePeer: no
   }
   
   address { 

   4

   
       prefix: closest
       distribution: closest
   }
   
   address {
       prefix: multicast
       distribution: multicast
   }
   
   address {
       prefix: unicast
       distribution: closest
   }
   
   address {
       prefix: exclusive
       distribution: closest
   }
   
   address {
       prefix: broadcast
       distribution: multicast
   }

   1

   By default, the router operates in standalone mode. This means that it can only communicate with endpoints that are directly connected to it. It cannot connect to other routers, or participate in a router network.

   2

   The unique identifier of the router. This ID is used as the container-id (container name) at the AMQP protocol level. If it is not specified, the router shall generate a random identifier at startup.

   3

   The listener entity handles incoming connections from client endpoints. By default, the router listens on all network interfaces on the default AMQP port (5672).

   4

   By default, the router is configured to use the message routing mechanism. Each address entity defines how messages that are received with a particular address prefix should be distributed. For example, all messages with addresses that start with closest will be distributed using the closest distribution pattern.

   Note

   If a client requests a message with an address that is not defined in the router’s configuration file, the balanced distribution pattern will be used automatically.

Procedure

1. To start the router, use the qdrouterd command.

   This example uses the default configuration to start the router as a daemon:

   $ qdrouterd -d

   The router starts, using the default configuration file stored at /etc/qpid-dispatch/qdrouterd.conf.

2. View the log to verify the router status:

   $ qdstat --log

   This example shows that the router was correctly installed, is running, and is ready to route traffic between clients:

   $ qdstat --log
   Fri May 20 09:38:03 2017 SERVER (info) Container Name: Router.A
   Fri May 20 09:38:03 2017 ROUTER (info) Router started in Standalone mode
   Fri May 20 09:38:03 2017 ROUTER (info) Router Core thread running. 0/Router.A
   Fri May 20 09:38:03 2017 ROUTER (info) In-process subscription M/$management
   Fri May 20 09:38:03 2017 AGENT (info) Activating management agent on $_management_internal
   Fri May 20 09:38:03 2017 ROUTER (info) In-process subscription L/$management
   Fri May 20 09:38:03 2017 ROUTER (info) In-process subscription L/$_management_internal
   Fri May 20 09:38:03 2017 DISPLAYNAME (info) Activating DisplayNameService on $displayname
   Fri May 20 09:38:03 2017 ROUTER (info) In-process subscription L/$displayname
   Fri May 20 09:38:03 2017 CONN_MGR (info) Configured Listener: 0.0.0.0:amqp proto=any role=normal
   Fri May 20 09:38:03 2017 POLICY (info) Policy configured maximumConnections: 0, policyFolder: '', access rules enabled: 'false'
   Fri May 20 09:38:03 2017 POLICY (info) Policy fallback defaultApplication is disabled
   Fri May 20 09:38:03 2017 SERVER (info) Operational, 4 Threads Running

Procedure

1. Navigate to the AMQ Python examples directory.

   $ cd <install-dir>/examples/python/

   <install-dir>

   The directory where you installed AMQ Python.

2. Start the simple_recv.py receiver client.

   $ python simple_recv.py -a 127.0.0.1:5672/examples -m 5

   This command starts the receiver and listens on the examples address (127.0.0.1:5672/examples). The receiver is also set to receive a maximum of five messages.

   Note

   In practice, the order in which you start senders and receivers does not matter. In both cases, messages will be sent as soon as the receiver comes online.

3. In a new terminal window, navigate to the Python examples directory and run the simple_send.py example:

   $ cd <install-dir>/examples/python/
   $ python simple_send.py -a 127.0.0.1:5672/examples -m 5

   This command sends five auto-generated messages to the examples address (127.0.0.1:5672/examples) and then confirms that they were delivered and acknowledged by the receiver:

   all messages confirmed

4. Verify that the receiver client received the messages.

   The receiver client should display the contents of the five messages:

   {u'sequence': 1L}
   {u'sequence': 2L}
   {u'sequence': 3L}
   {u'sequence': 4L}
   {u'sequence': 5L}