Resolving trace problems when developing message flows

Follow this advice to deal with some common trace problems that can arise when you develop message flows.

About this task

Scenario: You have generated a service trace file for your message flow, to trace the path of a message. However, you cannot determine which node is being referenced in the trace file.
Explanation: In the trace file you might see text such as:
```
Video_Test#FCMComposite_1_1 ComIbmMQInputNode , Video_Test.VIDEO_XML_IN
```
The elements in the text have the following meanings:

Video_Test

is the name of the message flow

FCMComposite_1_1

is the internal name for the node

ComIbmMQInputNode

is the type of node

VIDEO_XML_IN

is the node label, and is the name you see in your flow

The number at the end of the internal name is incremented; for example, FCMComposite_1_4 would be the fourth node you added to your flow. In the example, this section of the trace is referring to the first node in the message flow.

Scenario: You cannot see any alerts for an integration server or message flow in the Alerts viewer when you use the mqsichangetrace command to change the user trace setting.
Explanation: No alert is generated when an integration server runs user trace at normal or debug level. Alerts are generated only for message flow trace. For message flow trace, the IBM® Integration Toolkit is not notified of trace changes that are initiated by the mqsichangetrace command.
Solution: To see the alert, refresh the message flow, or disconnect, then reconnect to the domain.

Scenario: You are using a Trace node on UNIX and have set the Destination property to Local Error Log. You send a message to the Trace node that consists of multiple lines, but the message that appears in the syslog is truncated at the end of the first line.
Explanation: On UNIX, syslog entries are restricted in length and messages that are sent to the syslog are truncated by the new line character.
Solution: To record a large amount of data in a log on UNIX, set the Destination property on the Trace node to File or User Trace instead of Local Error Log.