IBM Websphere Message Broker : Starting user trace and Stopping user trace - Middleware News

Use user trace for debugging your applications; you can trace brokers, execution groups, and deployed message flows. Start user trace facilities using the mqsichangetrace command or the WebSphere® Message Broker Explorer.

Before you start:

Before you start to trace a broker, or one of its execution groups or message flows, the broker must be running, and you must have deployed the message flows by using the WebSphere Message BrokerExplorer. Follow the instructions in the Packaging and deploying topic.

To start a user trace:

1. Start WebSphere Message Broker user trace facilities by using the mqsichangetrace command, or, for execution groups and assigned message flows, from the WebSphere Message Broker Explorer.You can select only one broker on each invocation of the command, but you can activate concurrent traces for more than one broker, by invoking the command more than once.
2. Specify an individual execution group or message flow within the specified broker to limit the scope of a trace. The events that are recorded when you select the message flow option include:
   • Sending a message from one Message Processing node to the next
   • Evaluating expressions in a Compute or Filter node
3. Start your trace. You can start trace at two levels:

   normal

   This tracks events that affect objects that you create and delete, such as nodes.

   debug

   This tracks the beginning and end of a process, as well as monitoring objects that are affected by that process.

Example: starting user trace for the default execution group

To start normal level user tracing for the default execution group on a broker that you have created with the name MB8BROKER, on distributed systems, enter the command

mqsichangetrace MB8BROKER -u -e default -l normal

where:

-u specifies user trace
-e specifies the execution group (in this case, the default execution group)
-l specifies the level of trace (in this case, normal)

 On z/OS®, enter the command

F MQP1BRK,ct u=yes, e='default', l=normal

Example: starting user trace on all the message flows in the default execution group from the WebSphere Message Broker Explorer

To start normal level user tracing on all the message flows in the default execution group from theWebSphere Message Broker Explorer:

1. In the Navigator view, expand the Brokers folder and right-click the execution group with which you want to work.
2. Click User Trace All Flows > Normal

Example: starting user trace for a message flow from the WebSphere Message Broker Explorer

To start normal level user tracing for one of your message flows from the WebSphere Message BrokerExplorer:

1. In the Navigator view, expand the Brokers folder and right-click the message flow with which you want to work.
2. Click User Trace > Normal

An alert saying Message Flow is tracing at level 'normal' is displayed in the Alert Viewer.

Stopping user trace

Use user trace for debugging your applications; you can trace brokers, execution groups, and deployed message flows. Stop user trace facilities by using the mqsichangetrace command or the WebSphere® Message Broker Explorer.

Use the mqsichangetrace command with a trace level of none to stop an active trace. This action stops the trace activity for the component that you specify on the command. It does not affect active traces on other components. For example, if you stop tracing on the execution group test, an active trace on another execution group continues.

You can also stop an active trace for execution groups or assigned message flows by using theWebSphere Message Broker Explorer. If you redeploy a component from the WebSphere Message BrokerExplorer, trace for that component is returned to its default setting of none.

Example: stopping user trace on the default execution group

To stop the trace started by the command shown in Starting user trace, on distributed systems, enter the following command:

mqsichangetrace MB8BROKER -u -e default -l none 

where:

-u specifies user trace
-e specifies the execution group (in this case, the default execution group)
-l specifies the level of trace (in this case, none)

 On z/OS®, enter the following command:

F MQP1BRK,ct u=yes, e='default', l=none

Example: stopping user trace on a message flow from the WebSphere Message Broker Explorer

You can stop user trace on individual message flows, or select an execution group and stop user trace on all the message flows in the execution group.

To stop trace for one of your message flows from the WebSphere Message Broker Explorer:

1. In the Navigator view, expand the Brokers folder and right-click the message flow with which you want to work.
2. Click User trace > None.