Increasing the visibility of messages using WebSphere MQ application activity Trace

Brief introduction

This article uses multiple scenarios to demonstrate the potential use of IBMWEBSPHEREMQ application activity trace, including problem determination and maintenance of audit trails for WebSphere MQ messages. Two tools are used in each scenario to format the application activity Trace record for profiling:

Command line tool Amqsact, which is provided as an example with WebSphere MQ.

Event and Statistic Viewer included in Supportpac ms0p: WebSphere MQ explorer–extended Management plug-ins. Download Supportpac ms0p.

Open Application Activity Trace

Application activity Trace activation is controlled by a Queue manager property named Actvtrc. To turn on tracing, you use the RUNMQSC command ALTER QMGR actvtrc (ON). To turn off tracing, use the RUNMQSC command to ALTER QMGR actvtrc (off). Starting or stopping application activity Trace does not require a restart of the queue Manager.

In WebSphere MQ Explorer, you can also turn application activity Trace on or off in the online monitoring section of the Queue Manager properties, as shown in Figure 1:

Figure 1. Enable application activity Trace with WebSphere MQ Explorer

You can also open application activity Trace in a mqconnx call. For more information, see the MQCONNX option for the WebSphere MQ Information Center.

Configuring Application Activity Trace

The profile Mqat.ini allows you to control the frequency and verbosity of application activity Trace. The Mqat.ini file is located in the Queue Manager data directory:

:/var/mqm/qmgrs/<qm_name> on Linux and Unix

On the microsoftwindows: C:\Program files\ibm\websphere mq\qmgrs\<qm_name>

The <qm_name> is the name of the queue manager.

You can dynamically modify the INI file without restarting the Queue Manager. All you need to do is close application activity Trace and reopen it, and the change will take effect.

Select Application activity Trace level

There are a number of options for configuring the verbosity level in the application activity Trace output. The configuration options in the Mqat.ini file include:

The ability to limit the applications for which tracing is run. For example, you can specify the application to be tracked by specifying Applname in the Applicationtrace section. Because the WebSphere MQ V7.5 Java client currently contains the real application name rather than the Java-oriented general-purpose WebSphere MQ client, there is more flexibility in tracking Java applications now.

Select to include message data in the application Activity Trace message.

The ability to configure the time interval between trace messages and batch processing of multiple trace records into a single message. This feature allows you to modify the number of messages that are generated by application activity Trace, given the need to prioritize performance. The default is to generate a application activity Trace record for each message queue Interface (MQI) call that connects to the queue manager. Each application activity trace message contains 100 trace records.

The ability to configure the level of detail that is contained in application activity Trace, as described in the next section.