Make sure the required jar files are in JMeter's lib directory. If they are not, shutdown JMeter, copy the jar files over and restart JMeter. See Getting Started for details.

In this section, you will learn how to create a Test Plan to test a JMS Point-to-Point messaging solution. The setup of the test is 1 threadgroup with 5 threads sending 4 messages each through a request queue. A fixed reply queue will be used for monitoring the reply messages. To construct the Test Plan, you will use the following elements: Thread Group , JMS Point-to-Point , and Graph Results .

General notes on JMS: There are currently two JMS samplers. One uses JMS topics and the other uses queues. Topic messages are commonly known as pub/sub messaging. Topic messaging is generally used in cases where a message is published by a producer and consumed by multiple subscribers. A JMS sampler needs the JMS implementation jar files; for example, from Apache ActiveMQ. See here for the list of jars provided by ActiveMQ 3.0.

The first step you want to do with every JMeter Test Plan is to add a Thread Group element. The Thread Group tells JMeter the number of users you want to simulate, how often the users should send requests, and the how many requests they should send.

Go ahead and add the ThreadGroup element by first selecting the Test Plan, clicking your right mouse button to get the Add menu, and then select Add --> ThreadGroup.

You should now see the Thread Group element under Test Plan. If you do not see the element, then "expand" the Test Plan tree by clicking on the Test Plan element.

Next, you need to modify the default properties. Select the Thread Group element in the tree, if you have not already selected it. You should now see the Thread Group Control Panel in the right section of the JMeter window (see Figure 11.1 below)

Figure 11.1. Thread Group with Default Values

Start by providing a more descriptive name for our Thread Group. In the name field, enter Point-to-Point.

Next, increase the number of users (called threads) to 5.

In the next field, the Ramp-Up Period, leave set the value to 0 seconds. This property tells JMeter how long to delay between starting each user. For example, if you enter a Ramp-Up Period of 5 seconds, JMeter will finish starting all of your users by the end of the 5 seconds. So, if we have 5 users and a 5 second Ramp-Up Period, then the delay between starting users would be 1 second (5 users / 5 seconds = 1 user per second). If you set the value to 0, then JMeter will immediately start all of your users.

Clear the checkbox labeled "Forever", and enter a value of 4 in the Loop Count field. This property tells JMeter how many times to repeat your test. If you enter a loop count value of 0, then JMeter will run your test only once. To have JMeter repeatedly run your Test Plan, select the Forever checkbox.

In most applications, you have to manually accept changes you make in a Control Panel. However, in JMeter, the Control Panel automatically accepts your changes as you make them. If you change the name of an element, the tree will be updated with the new text after you leave the Control Panel (for example, when selecting another tree element).

Start by adding the sampler JMS Point-to-Point to the Point-to-Point element (Add --> Sampler --> JMS Point-to-Point). Then, select the JMS Point-to-Point sampler element in the tree. In building the example a configuration will be provided that works with ActiveMQ 3.0.

Name	Value	Description
JMS Resources
QueueuConnectionFactory	ConnectionFactory	This is the default JNDI entry for the connection factory within active mq.
JNDI Name Request Queue	Q.REQ	This is equal to the JNDI name defined in the JNDI properties.
JNDI Name Reply Queue	Q.RPL	This is equal to the JNDI name defined in the JNDI properties.
Message Properties
Communication Style	Request Response	This means that you need at least a service that responds to the requests.
Content	test	This is just the content of the message.
JMS Properties		Nothing needed for active mq.
JNDI Properties
InitialContextFactory	org.apache.activemq.jndi.ActiveMQInitialContextFactory	The standard InitialContextFactory for Active MQ
Properties
queue.Q.REQ	example.A	This defines a JNDI name Q.REQ for the request queue that points to the queue example.A
queue.Q.RPL	example.B	This defines a JNDI name Q.RPL for the reply queue that points to the queue example.B
Provider URL
Provider URL	tcp://localhost:61616	This defines the URL of the active mq messaging system.

The final element you need to add to your Test Plan is a Listener . This element is responsible for storing all of the results of your JMS requests in a file and presenting a visual model of the data.

Select the Thread Group element and add a Graph Results listener (Add --> Listener --> Graph Results). Next, you need to specify a directory and filename of the output file. You can either type it into the filename field, or select the Browse button and browse to a directory and then enter a filename.

Figure 11.2. Graph Results Listener