Attaching the flow debugger to an execution group for debugging

Before you can debug your message flow, you must attach the flow debugger to the execution group where your flow is deployed, and then start a debugging session.

Before you start:

From a single workbench, you can attach the flow debugger to multiple execution groups that are running on the same or on different host computers, and debug their flows (and therefore multiple messages) simultaneously.

Start of changeAn execution group can be debugged by only one user at a time. Therefore, if you attach your debugger to an execution group, another user cannot attach a debugger to that same execution group until you have ended your debugging session.End of change

The flow debugger can debug runtime brokers from previous versions. Select the version of the broker that you want to debug by checking the corresponding option on the Engine Selection panel in the Debug wizard, as described previously.

For details of which version of Rational Agent Controller (RAC) you must install on each of the broker operating systems, see Installing Rational Agent Controller.

You cannot debug flows that you have deployed to a 64-bit execution group; only 32-bit execution groups are supported by the flow debugger.

To attach the debugger to an execution group:

  1. Switch to the Broker Administration perspective. Note the name of your message flow as it is displayed in the Domains pane.
  2. Open the message flow that you want to debug in the Message Flow editor by double-clicking its name in the Broker Administration Navigator pane.
  3. Add a breakpoint to a connection that leads out of the input node to ensure that the message flow does not run to completion before you can begin to debug it.

    The breakpoint appears as Enabled breakpoint. For information about adding a breakpoint, see Working with breakpoints in the flow debugger.

  4. Switch to the Debug perspective.
  5. Click the down-arrow on the Debug icon Launch Debug on the toolbar, and click Debug to invoke the Debug (Create, manage, and run configurations) wizard.
    You are now creating a debug launch configuration. If you have created one previously, you can relaunch it by clicking directly on the Debug icon Launch Debug itself. This action generates an error if any of the following conditions are true:
    • You have not already created a debug launch configuration.
    • The broker and execution group to which you previously attached are no longer running.
    • The broker and execution group have been restarted and therefore have a new process ID (see below).
  6. In the list of configurations, select Message Broker Debug and click New. A set of tabbed panels is shown, beginning with Connect.

    You cannot click Debug until you complete the fields on the Connect panel. You can then choose to complete the fields on the other panels, or click Debug straight away.

    The panels in the wizard are:
    • Connect: use this panel to establish a connection to the execution group through the Rational Agent Controller. You must complete all the fields on this panel before you can click Debug to start a debugging session.
      Agent Controller port number
      Enter the port number that you want to use.
      Flow Project
      Select your flow project.
      HostName
      Select the host computer that the execution group is running on. If the host is not listed, enter the host name or IP address of the host computer in the HostName field (if the HostName field is not available, first click Reset, then make your changes).
      Execution group
      Select the broker and execution group that you want to debug. In the list box that opens when you click the Browse button, each execution group is listed as its process ID, followed by the name of the broker and the name of the execution group separated by a colon (referred to here as the "Engine name", for example:
      ProcessID    Engine name
      ---------    ---------------
      5984         WMBV6BR:default
      If the execution group does not appear in the list box, click Refresh to update the list box with the names of all execution groups that are currently deployed and available on the host computer. If the execution group still does not appear in the list box, try restarting RAC on the host computer.

      You are presented with the option of attaching to any execution group that is running on the target host. The list of execution groups includes those that do not have any flows deployed.

      The process number is theWindows® PID, as listed in the Task Manager on the Processes page. The PID was reported to you in the Event Log when you deployed, as described in Deploying a publish/subscribe topology.

      Now click Debug to go the next step, or complete the other panels.

      To debug a JavaCompute node, or a user-defined node containing Java™ code, configure the broker JVM with a debug port number. To set this value, issue the following command (all on one line):

      mqsichangeproperties <broker-name> -e <execution-group-name>
       -o ComIbmJVMManager -n jvmDebugPort -v <port-number>
      Restart the broker when this command has completed.
  7. Click Debug. In the Debug view, the name of the selected host computer and execution group are displayed.
  8. When the next message comes into your flow and arrives at breakpoint you added after the input node, the flow pauses, the breakpoint icon is highlighted: Enabled paused breakpoint, and you can start debugging.
  9. In the Debug view, double-click the message flow that you want to debug. The message flow opens in the Message Flow editor. You can now add more breakpoints, start stepping over the flow, and so on.

Next:

Continue with one of the following tasks:

Related concepts
Flow debugger overview
Related tasks
Installing Rational Agent Controller
Deploying
Debugging a message flow
Debug: ending a session
Related reference
Flow debugger shortcuts
Flow debugger icons and symbols
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Copyright IBM Corporation 1999, 2009Copyright IBM Corporation 1999, 2009.
Last updated : 2009-01-07 15:21:54

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