Before you start
To complete this task, you must have
completed the following tasks:
Before you can debug your message flow,
you must attach the flow debugger to the flow engine (execution group) where
your flow is deployed. If you want to, you can attach the flow debugger to
multiple flow engines that are running on the same or different host machines
and then simultaneously debug their flows.
To attach to the flow engine:
- Switch to the Flow Debug
perspective.
- Click the Attach to Flow Runtime icon
on
the toolbar to invoke the Attach to the Flow Engine wizard.
- If the host computer that contains the flow engine does not appear
in the Hosts list box, enter the host name or IP address
of the host computer in the Hostname or IP field, then
click Add to add the host to the Hosts list
box.
- In the Hosts list box, select the host computer
that the flow engine is running on and click Next.
- In the list box that opens, each flow engine is listed as the name
of the broker, followed by a colon, followed by the name of the execution
group, followed by the process number in brackets, for example: WMQIV5BR:default[2724].
If the flow engine does not appear in the list box, click Refresh to
update the list box with the names of all flow engines that are currently
deployed and available on the host computer. (If the flow engine still does
not appear in the list box, try restarting IBM Agent Controller on the host
computer).
Tip: The process number is the Windows
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 topology configuration.
- In the list box, select the flow engine containing the flow that
you want to debug, then click Finish. In
the Flow Debug view, the names of the selected host computer and flow engine
are displayed, as well as the names of the flows that are deployed in the
flow engine.
- In the Flow Debug view of the Flow Debug
perspective,
double-click the message flow that you want
to debug. The message flow opens in the Message
Flow editor.
- In the Message Flow editor, add a breakpoint to a connection that
leads out of the input node of the message flow. Adding this breakpoint ensures that the message flow does
not run to completion before you can begin to debug it.
The breakpoint
appears as
. (For information about adding a breakpoint, see Working with breakpoints).
- When the next message comes into your flow and arrives at the breakpoint,
the flow pauses, the breakpoint icon changes to
, and
you can start debugging.
Tip: From a single workbench,
the debugger can attach to more than one execution group, and debug multiple
flows in different execution groups (and therefore multiple messages) at the
same time. However, a deployed flow in one execution group can be debugged
by only one user at a time, so if you attach your debugger to it, another
user cannot also attach a debugger at the same time.