THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Prerequisite - Install Qpid Messaging
QMF uses Qpid Messaging as its means of communication. To use QMF, Qpid messaging must be installed somewhere in the network. Qpid can be downloaded as source from Apache, is packaged with a number of Linux distributions, and can be purchased from commercial vendors that use Qpid. Please see Download for information as to where to get Qpid Messaging.
Qpid Messaging includes a message broker (qpidd) which typically runs as a daemon on a system. It also includes client bindings in various programming languages. The Python-language client library includes the QMF console libraries needed for this tutorial.
Please note that Qpid Messaging has two broker implementations. One is implemented in C++ and the other in Java. At press time, QMF is supported only by the C++ broker.
If the goal is to get the tutorial examples up and running as quickly as possible, all of the Qpid components can be installed on a single system (even a laptop). For more realistic deployments, the broker can be deployed on a server and the client/QMF libraries installed on other systems.
Synchronous Console Operations
The Python console API for QMF can be used in a synchronous style, an asynchronous style, or a combination of both. Synchronous operations are conceptually simple and are well suited for user-interactive tasks. All operations are performed in the context of a Python function call. If communication over the message bus is required to complete an operation, the function call blocks and waits for the expected result (or timeout failure) before returning control to the caller.
Creating a QMF Console Session and Attaching to a Broker
For the purposes of this tutorial, code examples will be shown as they are entered in an interactive python session.
$ python Python 2.5.2 (r252:60911, Sep 30 2008, 15:41:38) [GCC 4.3.2 20080917 (Red Hat 4.3.2-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>
We will begin by importing the required libraries. If the Python client is properly installed, these libraries will be found normally by the Python interpreter.
>>> from qmf.console import Session
We must now create a Session object to manage this QMF console session.
>>> sess = Session()
If no arguments are supplied to the creation of Session, it defaults to synchronous-only operation. It also defaults to user-management of connections. More on this in a moment.
We will now establish a connection to the messaging broker. If the broker daemon is running on the local host, simply use the following:
>>> broker = sess.addBroker()
If the messaging broker is on a remote host, supply the URL to the broker in the addBroker function call. Here's how to connect to a local broker using the URL.
>>> broker = sess.addBroker("amqp://localhost")