Service trace

Service trace is a type of optional trace that is available in IBM® App Connect Enterprise, and it provides more information than that provided by the entries that are written to the Event Log or to user trace. Service trace is inactive by default; you must activate it explicitly by using a command.

With service trace, you can activate more comprehensive tracing of an integration node or server. You can also trace the execution of all the commands described in Commands, including the trace commands themselves.

Activate service trace only when you receive an error message that instructs you to, or when you are directed to do so by your IBM Support Center. You use the mqsichangetrace command to start service trace; you cannot start it through the IBM App Connect Enterprise Toolkit. For more information about how to use service trace, see Starting service trace.

When you activate service trace, you cause additional processing for every activity in the component that you are tracing. Large quantities of data are generated by the components, so you can expect performance to be affected while service trace is active. You can limit this additional processing by being selective about what you trace, and by restricting the time during which trace is active.

The location of the trace log depends on whether it is the trace for a command, an integration node (or integration server managed by an integration node), or an independent integration server:

Command trace:
The location of the trace log for a command is determined by the file name and path that you specify on the --trace parameter of the command. When you run a command with trace turned on, you specify the file in which the trace output will be written, as shown in the following example:
```
mqsilist myIntegrationNode --trace c:\tmp\listtrace.txt
```
The trace data is written to the specified file in plain text format (in this example, c:\tmp\listtrace.txt). The output is appended to the end of the file; if the file does not exist, it is created automatically.
Integration node trace:
The location of the trace logs for an integration node (or for an integration server that is managed by an integration node) depends on your environment:

Windows

If you have set the work path by using the -w parameter of the mqsicreatebroker command, the location is workpath\log.

If you have not specified the integration node work path, the default location is %PROGRAMDATA%\IBM\MQSI\Common\log where %PROGRAMDATA% is the environment variable that defines the system working directory. The default directory depends on the operating system.

Linux

/var/mqsi/common/log
When the log file is created, its file name is based on the integration node and integration server to which it relates; for example:
```
myIntegrationNodeName.myIntegrationServerName.trace.n.txt
```
where n is a number between 0-3, indicating this specific file in the series of four equally-sized files into which the trace log is divided.
Integration server trace:
For an independent integration server (which is not managed by an integration node), the trace logs are written to the following location:
```
<workdir>/config/common/log
```
The name of the log file takes the following form:
```
integration_server.myIntegrationServerName.trace.n.txt
```
where n is a number between 0-3, indicating this specific file in the series of four equally-sized files into which the trace log is divided.

The directory to which the service trace logs are written must be able to hold all the logs for that computer. You might want to place it on a separate file system, if that is allowed by your system operator.