Testing WebSphere MQ with LoadRunner

There are a couple of options for testing a WebSphere MQ-based system using LoadRunner, but this blog post shows my preferred approach: write some simple Java code to put a message on a queue (and get a message from a queue).

Note that this approach requires that you have a Java-based LoadRunner license such as the Java Tempate vuser or the Java Record-Replay vuser. You are not likely to need many virtual users, even if you want to generate a lot of messages.

If you need to test a message-based system, you might also be interested in reading about testing JMS with LoadRunner.

/*
 * Example WebSphere MQ LoadRunner script (written in Java)
 * 
 * Script Description: 
 *     This script puts a message on a queue, then gets a response message from 
 *     another queue.
 *
 * You will probably need to add the following jar files to your classpath
 *   - com.ibm.mq.jar
 *   - connector.jar
 *   - com.ibm.mq.jmqi.jar
 *   - com.ibm.mq.headers.jar
 *   - com.ibm.mq.commonservices.jar
 */
 
import lrapi.lr;
import com.ibm.mq.*;

public class Actions
{
    // Variables used by more than one method
    String queueMgrName = "TESTQMGR";
    String putQueueName = "TEST.INBOUND.QUEUE";
    String getQueueName = "TEST.REPLY.QUEUE";
    
    MQQueueManager queueMgr = null;
    MQQueue getQueue = null;
    MQQueue putQueue = null;
    MQPutMessageOptions pmo = new MQPutMessageOptions();
    MQGetMessageOptions gmo = new MQGetMessageOptions();
    MQMessage requestMsg = new MQMessage();
    MQMessage responseMsg = new MQMessage();
    String msgBody = null;

    public int init() throws Throwable {
        // Open a connection to the queue manager and the put/get queues
        try {
            // As values set in the MQEnvironment class take effect when the 
            // MQQueueManager constructor is called, you must set the values 
            // in the MQEnvironment class before you construct an MQQueueManager object.
            MQEnvironment.hostname="mqsvr.myloadtest.com";
            MQEnvironment.port=1414;
            MQEnvironment.channel = "WMQTOOL.ADMIN.CLIENT";
            queueMgr = new MQQueueManager(queueMgrName);
            
            // Access the put/get queues. Note the open options used.
            putQueue = queueMgr.accessQueue(putQueueName, MQC.MQOO_BIND_NOT_FIXED | MQC.MQOO_OUTPUT);
            getQueue= queueMgr.accessQueue(getQueueName, MQC.MQOO_INPUT_AS_Q_DEF | MQC.MQOO_OUTPUT);
        } catch(Exception e) {
            lr.error_message("Error connecting to queue manager or accessing queues.");
            lr.exit(lr.EXIT_VUSER, lr.FAIL);
        }
        
        return 0;
    }//end of init
 
    public int action() throws Throwable {
        // This is an XML message that will be put on the queue. Could do some fancy 
        // things with XML classes here if necessary.
        // The message string can contain {parameters} if lr.eval_string() is used.
        msgBody = lr.eval_string("{OrderNum}"); 
    	
        // Clear the message objects on each iteration.
        requestMsg.clearMessage();
        responseMsg.clearMessage();
        
        // Create a message object and put it on the request queue
        lr.start_transaction("test_message");
        try {
            pmo.options = MQC.MQPMO_NEW_MSG_ID; // The queue manager replaces the contents of the MsgId field in MQMD with a new message identifier.
            requestMsg.replyToQueueName = getQueueName; // the response should be put on this queue
            requestMsg.report=MQC.MQRO_PASS_MSG_ID; //If a report or reply is generated as a result of this message, the MsgId of this message is copied to the MsgId of the report or reply message.
            requestMsg.format = MQC.MQFMT_STRING; // Set message format. The application message data can be either an SBCS string (single-byte character set), or a DBCS string (double-byte character set). 
            requestMsg.messageType=MQC.MQMT_REQUEST; // The message is one that requires a reply.
            requestMsg.writeString(msgBody); // message payload
            putQueue.put(requestMsg, pmo);
        } catch(Exception e) {
        	lr.error_message("Error sending message.");
        	lr.exit(lr.EXIT_VUSER, lr.FAIL);
        }
        
        // Get the response message object from the response queue
        try {
            responseMsg.correlationId = requestMsg.messageId; // The Id to be matched against when getting a message from a queue
            gmo.matchOptions=MQC.MQMO_MATCH_CORREL_ID; // The message to be retrieved must have a correlation identifier that matches the value of the CorrelId field in the MsgDesc parameter of the MQGET call.
            gmo.options=MQC.MQGMO_WAIT; // The application waits until a suitable message arrives.
            gmo.waitInterval=60000; // timeout in ms
            getQueue.get(responseMsg, gmo);

            // Check the message content
            byte[] responseMsgData = responseMsg.readStringOfByteLength(responseMsg.getTotalMessageLength()).getBytes();
            String msg = new String(responseMsgData);
            lr.output_message(msg); // for debugging. Disable this for a load test.
            // TODO: add your own message checking here using string functions.
            // I have found that extracting XML fields and comparing them (rather than 
            // comparing the whole message body or substrings) is more resistant to change.
            // If no match is found, then lr.error_message() and lr.exit().
        } catch() {
            lr.error_message("Error receiving message.");
            lr.exit(lr.EXIT_VUSER, lr.FAIL);
        }
        lr.end_transaction("test_message", lr.AUTO);
        
        return 0;
    }//end of action
 
    public int end() throws Throwable {
        // 	Close all the connections
        try {
            putQueue.close();
            getQueue.close();
            queueMgr.close();
        } catch(Exception e) {
            lr.error_message("Exception in closing the connections");
            lr.exit(lr.EXIT_VUSER, lr.FAIL);
        }

        return 0;
    }//end of end
}

Please leave a comment if you find any errors in the code above, as I no longer have access to a WebSphere MQ environment to test this with.